7.1.4 Management of differences and disorders of sex development in the newborn

The birth of a new baby is one of the greatest wonders of nature. The first question that is usually posed by the new parent is 'is it a boy or a girl?'; without this information the parents cannot even formulate the second question, which is usually 'is he/she alright?'. It is no wonder that the birth of a child with an abnormality of genital development where the sex of rearing is uncertain at birth, presents difficult clinical and ethical issues. However, the recognition of genital ambiguity may depend on the expertise of the observer. The prevalence of genital anomalies at birth may be as high as 1 in 300 births (1), the prevalence of complex anomalies that may lead to true genital ambiguity may be as low as 1 in 5000 births (2). Rather than treating every affected child as a medical emergency, it is paramount that such a child is first assessed by an expert with adequate knowledge about the range of variation in the physical appearance of genitalia, the underlying pathophysiology of disorders of sex development, and the strengths and weaknesses of the tests that can be performed in early infancy. This expert should be able to ensure that the parents’ needs for information are comprehensively addressed, while appropriate investigations are performed in a timely fashion. This expert also needs to have immediate access to the multidisciplinary team that is essential for the management of such a child. Finally, in the field of rare conditions, it is imperative that the clinician shares the experience with others through national and international clinical and research collaboration.

The use of terminology that is clear and easy to use and understand by all health professionals, patients, and their families, is fundamental to the understanding, investigation and management of affected newborns and children. In addition, terminology should respect the individual and avoid terms that might cause offence. The term ‘intersex’ has had variable connotations even within professionals; some employed it as a term that covered all affected newborns, while at the other end of the spectrum, some believed that the term should only apply to those where there is complete mismatch between chromosomal and anatomic sex. The consensus reached in 2005 on management of these patients, stressed the importance of the aspect of terminology and recommended the substitution of the term ‘intersex’ with ‘disorder of sex development (DSD)’, which is defined as any congenital condition in which development of chromosomal, gonadal, or anatomic sex is atypical (3). It also recommended the abandonment of terms such as ‘pseudohermaphroditism’ and ‘true hermaphroditism’. Whilst the new nomenclature (Table 7.1.4.1) is easier to use and understand, and helps the professional planning investigations, it will nevertheless evolve over time as our understanding of long-term outcome, as well as molecular aetiology, improves. Given that genital anomalies may occur as commonly as 1 in 300 births and may not always be associated with a functional abnormality, some have advocated the use of ‘differences’ in preference to the term ‘disorder’ (4, 5). The strength of the acronym ‘DSD’ is that it can be used to cover both differences and disorders of sex development. However, the likelihood of this difference existing as a disorder will depend on the functional implications of the condition, which may be heavily influenced by the social and cultural framework within which the child exists.

Optimal clinical management of infants with DSD should comprise the following principles:

The initial contact with the parents of a child with a DSD is important as first impressions from these encounters often persist. A key point to emphasize is that the child with a DSD has the potential to become a well-adjusted, functional member of society. The use of the phrase ‘differences in sex development’ may be particularly beneficial in introducing the concept of the range of variation in sex development that can be encountered to those with little prior knowledge of the field. It should be emphasized that DSD is not shameful. In those cases where there are no doubts about sex assignment, it should not be assumed that the parents’ need for information and psychological help are any less; the parents’ perception of risk may be quite different from the clinical perception of the severity of illness (6). In those cases where there is true genital ambiguity, it should be explained to the parents that the best course of action may not initially be clear, but the health care team will work with the family to reach the best possible set of decisions in the circumstances. The health care team should discuss with the parents what information to share in the early stages with family members and friends. It is essential that the parents do not register the birth until the sex of rearing is established. Parents need to be informed about sex development; they should be provided with written information and directed to Internet-based information (Box 7.1.4.1). Ample time and opportunity should be made for continued discussion with review of information previously provided.

Optimal care for children with DSD requires an experienced multidisciplinary team that is generally found in regional centres. The team may exist as a clinical network with links to other children’s centres (Scottish Genital Anomaly Network: www.sgan.nhsscotland.com). Ideally, the team includes paediatric subspecialists in endocrinology, surgery and/or urology, psychology/psychiatry, gynaecology, genetics, neonatology, nursing and, if possible, social work, and medical ethics. Core composition will vary according to DSD type, local resources, developmental context, and location. Ongoing communication with the family’s primary care physician is important. The team has a responsibility to educate other health care staff in the appropriate initial management of affected newborns and their families, and should also have the ability to review and discuss its own performance through the audit of clinical activity, and attendance at joint clinics and education events. For new infants with a DSD, the team should develop a plan for clinical management with respect to diagnosis, gender assignment, and treatment options before making any recommendations. Ideally, discussions with the family are conducted by one professional with appropriate communication skills. Transitional care should be organized with the multidisciplinary team operating in an environment comprising specialists with experience in both paediatric and adult practice. Support groups have an important role to play, and their contact details should be supplied to the parents; it is possible that affected parents may prefer to talk to local families affected in a similar way. The availability of such a local pool of voluntary helpers who had some support from the specialists would complete the composition of the multidisciplinary team.

The infant with a suspected DSD may need evaluation for four broad reasons. First, there may be a need to determine the sex of rearing. Secondly, there may be concerns about immediate, life-threatening metabolic conditions that are more likely to be associated with certain diagnoses that are, for instance, associated with adrenal insufficiency. Thirdly, an improved knowledge of the aetiology of the underlying condition may allow the development of a long-term management plan. Finally, continued evaluation over the longer-term will allow the affected individuals and their care-providers to understand issues, such as fertility, sexual function, and the risk of tumour development, and help with informed disclosure of the diagnosis itself.

It is very likely that the clinician from whom a specialist opinion is sought will encounter the infant and the parents after the family have already been seen by other health professionals. Their anticipation of meeting someone who can answer all their questions, provide them with reassurance, and solve all the problems, can be a daunting and impossible task for a single clinician, irrespective of their level of expertise. It is likely that this clinician will form a long-lasting relationship with this family and over time with the help of the multidisciplinary team will be able to address most of the issues above. It is, therefore, very important to have a positive and systematic approach that starts the first encounter with the family with emphasis on the general well-being of the child.

An adequate history should concentrate particularly on:

Family history: parental consanguinity, history of an infant with salt-losing, unexplained infant deaths, or DSD in relatives. These elements may indicate autosomal recessive genetic disorders associated with disturbed steroidogenesis (usually CAH). In contrast, an X-linked recessive mode of inheritance is suggestive of androgen insensitivity syndrome (AIS).

Antenatal history: maternal ingestion of drugs, which may cause fetal virilization (androgens), or signs of maternal androgen excess, which may indicate a maternal androgen secreting tumour. Exposure to specific environmental factors able to inhibit virilization of the fetus. Some assisted conception techniques include progestagen containing drugs and these methods increase the likelihood of male offspring with genital anomalies.

Information about antenatal counselling and results of prenatal tests: knowledge of what has already been discussed with the parents by health professionals, and their understanding of the information, is essential:

The general physical examination should determine whether there are any dysmorphic features and the general health of the baby. Affected infants, particularly those who have XY DSD, are more likely to be small for gestational age and may display other developmental anomalies (1). Examples of some known syndromes that are associated with genital anomalies and their characteristic features in early infancy are listed in Table 7.1.4.2. In addition to a systematic examination, the affected infant should be examined for mid-line defects, which may point towards an abnormality of the hypothalamopituitary axis. The state of hydration and blood pressure should be assessed as various forms of adrenal steroid biosynthetic defects can be associated with differing degrees of salt loss, varying degrees of masculinization in girls or under-masculinization in boys, or hypertension. Although the cardiovascular collapse with salt loss and hyperkalaemia in congenital adrenal hyperplasia does not usually occur until the second week of life (with salt loss usually evident from day 4) and so will not be apparent at birth in a well neonate, it should be anticipated in a suspected case. Jaundice (both conjugated and unconjugated) may be observed in cases of hypopituitarism or cortisol deficiency. The urine should be checked for protein as a screen for any associated renal anomaly (for example, Denys–Drash/Frasier syndromes) and a prefeed blood glucose should be checked for hypoglycaemia (suggestive of hypopituitarism, or occasionally in CAH, e.g. 3β-HSD deficiency). Renal tract anomalies, such as ureteropelvic junction obstruction, vesico-ureteric reflux, pelvic or horseshoe kidney, crossed renal ectopia, and renal agenesis may occur in as many as 1 and 5% of cases with isolated distal and proximal hypospadias, respectively (7).

A detailed physical examination and documentation of the genitalia is necessary to evaluate the degree of genital anomaly. The first step is a careful inspection and palpation. In a number of infants, gonads or swellings may be visible in the labioscrotal folds or the inguinal regions, but they may disappear on palpation. In those presenting with apparently normal female external genitalia, bilateral hernias containing testes (and, rarely uterus or fallopian tubes) should be sought by palpation. In any case, if gonads are palpated externally, these will be testes (ovaries tend to remain in the pelvic position) or, rarely, ovotestes. A careful measurement of the phallus (stretched dorsal length) and comparison to published normative data (3) is recommended to assess the extent of deviation of the appearance from normal and to explain this difference to the parents. The presence or absence of a chordee should be noted; the location of two (urethral and vaginal) or one orifice (urethral or urogenital sinus) that opens on the dorsal (epispadias) or ventral surface (hypospadias) of the phallic structure should be noted. An epispadias is a very rare condition and is usually part of a spectrum of conditions (bladder and cloacal exstrophy) where there can be a failure of fusion of a number of lower abdominal and pelvic organs including external genitalia. Hypospadias is a much commoner condition where the location of the urethral orifice may be proximal and close to the perineum, mid-shaft or distal and close to the coronal sulcus or the glans. The description of the degree of labioscrotal fold fusion, i.e. complete absence of scrotal fusion, a posterior fusion of labia majora, a partially fused hemiscrotum or completely fused scrotum is also very important. Finally, the nature of the skin of the genitalia and labioscrotal folds (texture and pigmentation) and the shape of the folds and whether they are sac-like provides helpful information on androgenization and the possibility of finding testes.

Although scoring systems such as the Prader score for XX DSD (8) and modifications of this system for XY DSD (9, 10) may provide an integrated summary description of the genitalia, these scoring systems are not sufficiently discriminative to portray the full spectrum of the variation encountered in the external genitalia. The external masculinization score (EMS), which scores external genitalia individually for scrotal fusion, microphallus, location of urethral meatus, and location of each gonad may be a more discriminative and objective method of describing the external appearance (11) (Fig. 7.1.4.1).

There are clear reasons for investigating an infant with genital anomalies and these include determination of sex of rearing, concerns about early medical problems, concerns about medical and surgical problems in later childhood, and development of a long-term plan that anticipates future health issues, such as sexual development and function, tumour risk, and fertility. A clear knowledge of the underlying aetiology may also facilitate explanation of the condition to the parent and the older child. Thus, investigations should be performed with these different objectives in mind, and should be split into first-line and second-line investigations. First-line investigations should, in most cases, be sufficient to guide sex of rearing, exclude early medical problems and provide an idea of the nature of the problem. In the newborn infant, detailed dynamic endocrine investigations should only be performed if they can alter the management of the child; in most cases, these investigations can be performed after 3 months when many reproductive and adrenal-related hormones have reached a status quo and the results are easier to interpret. Furthermore, collecting blood samples maybe simpler in the older child and collection of multiple blood samples from an otherwise well infant may exert unnecessary stress on the child’s parents.

Most infants with a suspected DSD will present with:

The greatest amount of debate regarding the need for investigation involves the case of the boy presenting with hypospadias and/or cryptorchidism, i.e. the under-masculinized boy. Considerable variation exists about the extent to which these infants should be investigated (12). Routine systematic examination of 423 consecutive newborn boys in one hospital revealed that 412 (98%) had an EMS of 12. The median (10th centile) EMS for the group of 11 infants with an EMS of less than 12 was 11(11). One infant with isolated micropenis had an EMS of 9; three infants with isolated glandular hypospadias had an EMS of 11; three infants with absent unilateral testis also had an EMS of 11; four infants with a unilateral inguinal testis had an EMS of 11.5. Thus, an EMS of less than 11 was only encountered in 1/423 boys (11). These data are similar to population data suggesting that genital anomalies occur in about 1:300 total births and 75% of these patients have an associated hypospadias (1). Population studies also suggest that approximately 50% of hypospadias cases affect the distal penis (glandular or coronal) (13). The largest study to date of karyotype analysis in children with isolated cryptorchidism, isolated hypsopadias or a combination of the two anomalies revealed chromosomal anomalies in 27 of the 916 patients with cryptorchidism (2.94%), in 7 of the 100 with hypospadias (7%), and in 4 of the 32 with a combination of cryptorchidism and hypospadias (12.5%) (14). The incidence of chromosome aberrations was 1.8% in cases of isolated cryptorchidism and 6.7% in those of other associated anomalies. In patients with hypospadias, abnormal karyotypes were only detected when there were additional congenital abnormalities. In one specialist centre, out of 63 unselected cases with proximal hypospadias (penoscrotal, scrotal, perineal) who were studied for all known causes of hypospadias with clinical, as well as molecular biological techniques, in 31% of cases an underlying aetiology was identified and this included complex genetic syndromes in 17%, chromosomal anomalies in 9.5%, vanishing testes syndrome in 1, the androgen insensitivity syndrome in 1, and 5α-reductase type 2 deficiency in 1, respectively (15). Thus, infants who require further evaluation and investigation should include all children with EMS of less than 11 and all children with familial hypospadias. This will avoid detailed investigations of boys with isolated glandular hypospadias and boys with isolated inguinal testes.

Typically, in the young infant with DSD, gonadal palpability combined with karyotyping, ultrasound examination for müllerian structures and determination of 17-hydroxyprogesterone level should provide a reasonable guide for the initial practical management of the newborn with a DSD (Fig. 7.1.4.2). The results of the karyotype and the ultrasound should be available within 48 h of presentation. While fluorescent in situ hybridization (FISH) or polymerase chain reaction (PCR) analysis using X and Y specific probes is sufficient for initial management it is recommended that these tests are confirmed by a formal karyotype. It also needs to be borne in mind that any mosaicism that is evident may be tissue dependent. Finally, karyotype should be repeated in cases of prenatal karyotype mismatch. While ultrasound examination is the commonest modality that is used for imaging of the internal sex organs, there are occasions when it may provide misleading results, especially when the infant is unwell, does not have a full bladder or the operator lacks experience. In such situations, there may be a need to consider other methods of imaging including MRI, a genitogram, or a laparoscopy (16, 17).

Due to the effects of stress of labour and insufficient time for accumulation of hormone in CAH, a sample for 17-hydroxyprogesterone may be difficult to interpret in an infant who is less than 36 hours old. Besides 17-hydroxyprogesterone, biochemistry tests should include serum testosterone, anti-müllerian hormone (AMH), cortisol, androstenedione, ACTH, and gonadotropins, in addition, a sample for DNA extraction and urine for analysis and steroid profile. It is likely that the biochemistry results will be available within a week. Any spare sample should be stored for analysis at a later date. The clinician needs to have an intimate knowledge of assays and normal values for age, and should establish a close liaison with the specialist biochemistry laboratory. Given that steroid hormones and gonadotropins fluctuate over the first few weeks of life, serial measurements are particularly valuable. This also applies to urea and electrolyte estimations; infants with salt-losing forms of congenital adrenal hyperplasia may start to show biochemical signs of salt loss from day 4, with a rise in potassium being the earliest sign. While it is safest to provide salt and mineralocorticoid where salt loss is suspected, it is also important to establish the diagnosis for long-term management. Urinary electrolytes are unhelpful. Sending a sample for plasma renin activity prior to treatment can be helpful retrospectively, and genetic analysis in CAH is informative. Monitoring weight is useful in any infant where there is a risk of salt loss.

Serum testosterone estimation has often been used as a marker of functioning testes, as well as a sign of intact pathways for the synthesis of testosterone. However, given that many commercially available testosterone assays are nonspecific in the early neonatal period (18) and can cross-react with other conjugated steroids, it is possible that for the newborn infant serum AMH level is a more diagnostically reliable marker of testes than serum testosterone. The use of serum AMH has been widely advocated as a method of assessment of genital anomalies especially as it can be a clear discriminator in cases of anorchia, 46, XY complete gonadal dysgenesis and cases of persistent müllerian duct syndrome (PMDS) with a defect of the AMH gene. There is a clear difference between AMH concentrations in boys and girls, especially in early childhood. In boys under the age of 8 years, a serum AMH concentration ≥ 200 pmol/l may be an appropriate cut-off mark to denote normality, given that it was the approximate 10th centile for this age range. However, AMH concentrations are generally higher in the young boy before they fall in late childhood (Fig. 7.1.4.3). It should also be noted that AMH concentrations tend to rise over the first 3 months in some young infants (19) and may in some cases be lower than 200 pmol/l at initial evaluation, although still above 25 pmol/l, which approximately represents the 90th centile for girls (20).

Second-line investigations will be guided by the results of the first-line investigations. In most cases, these tests are performed to investigate the underlying aetiology, but are usually not necessary to determine the sex of rearing.

These investigations could include:

Although controversy exists regarding the optimal regimen, stimulation with human chorionic gonadotropin (hCG) has been used to assess the presence of functioning testicular tissue and the detection of defects in testosterone biosynthesis and action for over 40 years (23). In the UK, a number of different protocols are used for hCG stimulation, but most use intramuscular hCG 1000–1500 units on 3 consecutive days for a standard test (12). If there is a poor response, this test can be followed by prolonged hCG stimulation 1500 units on 3 consecutive days for the first week followed by 1500 units on 2 days a week for the two following weeks. The combined regimen that is employed in our unit is outlined in Fig. 7.1.4.4. The definition of a normal response may depend on the age of the child and the regimen itself. In infants and older children, who have a more active gonadotropin axis, the Leydig cells may be more responsive to hCG stimulation and the shorter duration of hCG stimulation may be sufficient (24). Recently, in an older group of children with suspected hypogonadotrophic hypogonadism, cut-off for a normal testosterone response has been reported to be at 3.5 nmol/l after 3 days of stimulation and 9.5 nmol/l after the 3 week stimulation regimen (25). Besides testosterone, other androgens that should be assessed include dihydrotestosterone and androstenedione. For these two metabolites, the day 4 sample is more important than the day 1 sample. There is no additional benefit of collecting a sample for these two metabolites on day 22.

46, XX DSD can be divided into disorders of ovarian development, disorders of androgen synthesis, disorders of müllerian development, and other conditions affecting sex development.

Rarely, the developing ovary may contain some testicular tissue (ovotesticular DSD) or may develop as a functioning testis that secretes adequate amounts of testosterone for adequate virilization and AMH for regression of the müllerian ducts (testicular DSD). Ovotesticular DSD can be subclassified according to the type and location of the gonads. Lateral cases (20%) have a testis on one side and an ovary on the other. Bilateral cases (30%) have testicular and ovarian tissues present bilaterally as ovotestes. Unilateral cases (50%) have an ovotestis present on one side and a normal ovary or testis present on the other side. In ovotesticular DSD, the initial manifestations are ambiguous genitalia in almost all cases and the internal duct structures display gradations between male and female, and there is often a urogenital sinus, and a uterus or a hemi-uterus, or a rudimentary uterus on the side of the ovary or ovotestis. Breast development will occur in puberty and even menses may occur in a significant proportion when ovarian tissue is present. However, without removal of testicular tissue, these children will also proceed to virilization at puberty. Presence of functional testicular tissue can be investigated by checking AMH or testosterone levels following hCG stimulation. Assessment of functioning ovaries by biochemical markers has not been thoroughly explored and the utility of measuring estradiol after repeat FSH stimulation or measurement of an ovarian specific marker such as inhibin A requires further study. Two-thirds of affected children are raised as boys. If the testicular components are removed, serial AMH levels may allow adequate confirmation of complete removal of functioning testicular tissue. In contrast, 46,XX testicular DSD is usually associated with a normal male phenotype or a relatively mild abnormality of the male genitalia, such as distal or mid-shaft hypospadias. In adulthood, although testosterone synthesis is not affected, spermatogenesis is usually severely affected.

Ovarian Dysgenesis Ovarian dysgenesis is most frequently seen in association with sex chromosome aneuploidy such as Turner syndrome and related variants. However, these conditions do not present in infancy with physical abnormalities of sex development.

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is the commonest cause of 46,XX DSD and consensus guidelines exist for management of this condition in infancy, as well as in the older child (ref). The newborn girl with this condition can be virilized to a varying extent and as illustrated by the Prader classification (Fig. 7.1.4.1). High serum concentration of 17OH-progesterone (greater than 300 nmol/l) after the first 48 h of life, and high androstenedione and testosterone in the early neonatal period are the biochemical hallmarks of this condition. More than 75% of these infants will also be salt losers because of a deficiency of mineralocorticoid synthesis and the affected child will present with a salt losing crisis in the second or third week of life.

3β-hydroxysteroid dehydrogenase Type 2 catalyses the conversion of Δ⁵ steroids to Δ⁴ steroids and a deficiency of this enzyme results in adrenal insufficiency as well as accumulation of pregnenolone, dehydro-epiandrosterone (DHEA) and androstenediol. In peripheral tissues, as well as the placenta, the accumulating steroids, and particularly DHEA, can be converted to more potent androgens, such as testosterone, by the Type 1 isoenzyme. Most girls with this condition present with relatively mild signs of virilisation such as clitoromegaly, associated with adrenal deficiency.

Defects in P450 oxidoreductase (POR) can cause combined deficiencies of 21α-hydroxylase, 17α-hydroxylase, and aromatase enzymes, and this can be associated with abnormal genital development in both girls and boys. Children with this condition usually have cortisol deficiency, but have normal mineralocorticoid function.

This is the second commonest cause of virilizing congenital adrenal hyperplasia accounting for approximately 5% of all cases. Apart from a DSD, this condition may also be associated with hypertension and hypokalaemia, but these abnormalities are not universally present, particularly not in infancy. These abnormalities are due to the accumulation of 11-deoxycorticosterone, which is a weak mineralocorticoid. They may be associated with a low renin. Children with this condition usually have cortisol deficiency.

This is a rare condition, usually due to a heterozygous mutation in the glucocorticoid receptor α gene. The partial end-organ insensitivity leads to high ACTH, cortisol, mineralocorticoids, and androgens. One case of a girl with a homozygous mutation in this gene and a co-existing heterozygous mutation in CYP21 has been described to be associated with marked virilization at birth.

Aromatase deficiency is inherited as an autosmal recessive condition and has been described in approximately 10 girls with a variable extent of virilization. There is often a history of maternal virilization after the second trimester of pregnancy coupled with elevated maternal androgen levels that resolve after the pregnancy. In infancy and subsequently during puberty, these girls have high serum androgens and low oestrogen concentrations, show no signs of feminization and progressively virilize. In addition, inadequate oestrogen supplementation may be associated with osteoporosis and a failure of timely epiphyseal fusion.

Any maternal source of elevated androgens can induce virilization of the female fetus. Ovarian tumours include luteoma of pregnancy, arrhenoblastoma, hilar-cell tumour, masculinizing ovarian stromal cell tumour, and Krukenberg tumour. Discrepancy between the marked virilization of the mother and the minimal androgen effect in female offspring can be explained by the placental aromatase activity, which converts androgens to oestrogens, or to the metabolism of androgen, which thus becomes less active. Apart from untreated maternal virilizing CAH, androgen-secreting adrenal tumour in the mother is rare. In both cases, investigation of abnormal androgen production by the mother must be performed immediately after delivery. Maternal ingestion of androgens, progestagens, or other drugs is another cause of fetal virilization. Exogenous steroids administered during the pregnancy may cause posterior fusion of the labia, clitoral enlargement, and even increased degrees of androgenization. In the past, several oral progestational compounds given because of threatened abortion, have been implicated, such as 19-nor testosterone. Other drugs, like danazol or stilboestrol that are used in pregnancy, have also been associated with abnormalities of the genitalia.

Abnormalities in uterine development can result in bicornuate uterus, uterine hemiagenesis, hypoplasia, or agenesis. These can be associated with renal, cardiac, or spine abnormalities as part of the Mayer–Rokitansky–Kuster–Hauser (MRKH) syndrome or MURCS (mullerian, renal, cervical spine syndrome). On rare occasions, absence of müllerian structures and the presence of co-existing hyperandrogenaemia, has been associated with a mutation in the WNT4 gene (26). Other conditions, such as maturity onset diabetes of the young 5, the hand-foot-genital syndrome, and Laurence–Moon–Biedl syndrome have also been associated with abnormalities of müllerian development.

Complex urogenital abnormalities, such as cloacal anomalies, can affect both sexes and require major reconstructive surgery.

Clitoral lengths are variable and, when in doubt, should be compared with published norms (3). In addition, the clitoris may be enlarged in conditions such as neurofibromatosis. In any newborn girl, the labial folds may be very swollen and oedematous immediately after birth and may look like scrotal sacs. In premature babies, the lack of labial adipose tissue may make the relative size of the clitoris more pronounced so that it is mistaken for clitoromegaly. Labial adhesions and vaginal bleeding in the newborn are signs of the normal oestrogen surge in the newborn period.

46,XY DSD can be divided into disorders of testis development, disorders of androgen synthesis, disorders of androgen action, and other conditions affecting sex development. Biochemically, based on AMH and the hCG stimulation test, these disorders can also be divided into conditions where (1) AMH levels are low and testosterone levels do not rise following hCG stimulation–abnormalities of testis development or maintenance, (2) AMH levels are normal and testosterone levels do not rise following hCG stimulation–abnormalities of testosterone synthesis, (3) AMH levels are normal and testosterone levels do rise following hCG stimulation–abnormalities of testosterone action, dihydrotestosterone synthesis, persistent mullerian duct syndrome, or nonspecific disorders of masculinization, (4) AMH levels are low and testosterone levels do rise following hCG stimulation—persistent müllerian duct syndrome (Fig. 7.1.4.5). However, in many cases, the biochemical assessment will not allow clear delineation of cases into any of the four categories.

These disorders can have a spectrum of phenotypes and presentations. In the most extreme case, complete testicular dysgenesis, infants raised as girls do not present until adolescence with primary amenorrhoea. These girls will have normal external female genitalia and müllerian structures, and this condition is also often called Swyer's syndrome. Partial gonadal dysgenesis may be associated with a variable and internal phenotype even extending to a phenotype of simply male infertility. Accordingly, there will be a variable reduction in AMH and testosterone response to hCG stimulation. Given that several single gene disorders, as well as chromosomal rearrangements, have been described to be associated to the clinical picture of gonadal dysgenesis, the latter should not necessarily be considered the final diagnosis. These disorders are often associated with abnormalities in other systems and a thorough clinical evaluation of the affected infant will prove very useful in directing appropriate genetic analysis that can lead to the correct diagnosis. Currently, a genetic diagnosis is only reached in approximately 30% of cases of gonadal dysgenesis. The importance of reaching a genetic diagnosis in these cases is highlighted by conditions, such as those associated with a mutation in the steroidogenic factor (SF1) gene, which may occasionally be associated with adrenal deficiency or a mutation of the Wilms’ tumour-related gene-1 (WT1), where the DSD may be the first sign of conditions such as WAGR syndrome, Denys–Drash syndrome and Frasier syndrome.

Defects anywhere along the pathway of androgen synthesis and target organ action can result in an XY DSD.

A deficiency of 7-dehydrocholesterol reductase (DHCR7) results in a failure of cholesterol synthesis and results in the Smith–Lemli–Opitz syndrome, which is associated with a wide range of clinical features including microcephaly, cardiac defects, micrognathia, cleft palate, polydactyly, and syndactyly. These children may display mental retardation and growth failure. The genitalia in the affected XY infant may range from hypospadias to completely normal female external genitalia with no mullerian ducts. The condition is diagnosed by low levels of cholesterol and elevated levels of its precursor, 7-dehydrocholesterol, as well as an androgen deficiency, and a normal AMH. Adrenal insufficiency may occur in some cases and needs evaluation. Mutational analysis of the DHCR7 gene will provide confirmation of the diagnosis.

A defect of the luteinizing hormone receptor leads to impaired sensitivity to hCG and luteinizing hormone leading to Leydig cell agenesis or hypoplasia. The genitalia in the affected XY infant may range from isolated hypospadias or micropenis to completely normal female external genitalia with no müllerian ducts. The biochemical picture may include high basal and luteinizing hormone-releasing hormone (LHRH)-stimulated luteinizing hormone and follicle-stimulating hormone (FSH) levels. There is a poor response to hCG stimulation and the AMH levels should be normal. Histology of the testes in the prepubertal child will show a marked lack of Leydig cells. Mutational analysis of the luteinizing hormone/hCG receptor gene will provide further confirmation of the diagnosis.

Defects in the steroidogenic acute regulatory protein (StAR) lead to deranged intracellular transport of cholesterol and abnormalities of steroid biosynthesis. Affected XY infants have severe adrenal failure and the external genitalia are female with no müllerian structures. The testes may be palpable in the labioscrotal folds, but are usually undescended. CT or MRI imaging of the adrenal glands, as well as histology, may reveal lipid accumulation. This condition is commoner in Japan and Korea. A nonclassical form of this condition also exists and is associated with progressive adrenal insufficiency in early childhood, but without any overt abnormalities of androgen synthesis. Mutational analysis of the StAR gene will provide confirmation of the diagnosis.

Defects in the P450 side chain cleavage (P450scc) enzyme result in a failure of conversion of cholesterol to pregnenolone, which is the first common step in steroid biosynthesis. Affected XY infants have a phenotype that is very similar to congenital lipoid adrenal hyperplasia due to defect of the StAR protein. Mutational analysis of the P450scc gene (also called CYP11A1) will provide confirmation of the diagnosis.

Defects in 3β-HSD type 2 results in a failure to convert Δ⁵-steroids to Δ⁴-steroids. The genitalia in the affected XY infant may range from isolated hypospadias or micropenis to more severe undermasculinization, but not completely normal female external genitalia. There are no müllerian ducts. Besides a poor androgen response to hCG stimulation, affected infants will have adrenal deficiency which may not necessarily include salt wasting. A urine steroid profile that shows high concentrations of Δ⁵-steroids (e.g. 17OH-pregnenolone, pregnenolone, dehydro-epiandrosterone) and low concentrations of Δ⁴-steroids (e.g. progesterone and cortisol) is helpful. However, there is a need for careful analysis and interpretation of the steroid profile as extra adrenal/gonadal 3β-HSD Type 1 enzyme may raise the levels of some Δ⁴-steroids, such as androstenedione and 17OH-progesterone. Mutational analysis of the 3β-HSD type 2 gene (also called HSD3B2) will provide confirmation of the diagnosis.

Defects of the P450c17 enzyme can lead to a variable extent of combined deficiency of 17α-hydroxylase and 17,20-lyase activity. In the affected XY infant, this will be associated with a variable degree of undermasculinization ranging from mild abnormalities of the genitalia to unambiguously female external genitalia. Besides a poor androgen response to hCG stimulation, affected infants will have a poor cortisol response to adrenal stimulation, but may not display adrenal insufficiency as they have highly raised deoxycorticosterone levels that may lead to a state of low renin hypertension and hypokalaemic alkalosis in the older child. Mutational analysis of the P450c17 gene (also called CYP17) will provide confirmation of the diagnosis.

The P450 oxidoreductase enzyme is necessary for electron transfer from NADP to many P450 enzymes and its deficiency can affect the activity of a number of P450 enzymes. Infants with XY DSD and an abnormality of this enzyme tend to present with a clinical picture consistent with combined deficiency of 21α-hydroxylase deficiency and 17,20-lyase deficiency. The genitalia in the affected XY infant may range from isolated hypospadias or micropenis to more severe undermasculinization, but not completely normal female external genitalia. There are no müllerian ducts. Besides a poor testosterone response to hCG stimulation, affected infants will have adrenal deficiency, which is usually restricted to glucocorticoid deficiency. The deficiency of this enzyme may be associated with a condition called Antley–Bixler syndrome, which is a skeletal dysplasia classically characterized by radiohumeral stenosis and craniosynostosis. This syndrome is not universally associated with abnormalities of the P450 oxidoreductase enzyme. Mutational analysis of the P450 oxidoreductase gene (also called POR) may provide confirmation of the diagnosis.

17β–HSD has 6 isoenzymes that convert androstenedione, DHEA, and oestrone to testosterone. Deficiency of 17β–HSD type 3 is associated with XY DSD and affected infants often present with female external genitalia or sometimes ambiguous genitalia. However, these children can undergo spontaneous virilization during puberty with a rise in testosterone levels, possibly due to increased activity of the other isoenzymes. Thus, early accurate diagnosis of this condition is important as the affected infant may need sex reassignment if initially raised as a girl. These infants will have a poor testosterone response to hCG, but may have a relatively high level of serum androstenedione such that the testosterone:androstenedione ratio may be less than 0.8. However, this is not an invariable finding in this condition and, furthermore, a low ratio may also be found in poorly functioning testes. Mutational analysis of the 17β–HSD type 3 gene (also called HSD17B3) will provide confirmation of the diagnosis.

5α-RD exists as two isoenzymes. Type 1 is expressed in skin and type 2 in the genitalia and converts 5α to 5α steroids. In XY DSD infants may present with a variable phenotype ranging from micropenis or hypospadias to female external genitalia. This phenotype is due to reduced activity of 5α-RD type 2 and a failure to convert testosterone to dihydrotestosterone. The classical biochemical profile includes normal or high testosterone:dihydrotestosterone ratio following hCG stimulation, which usually exceeds 30:1. An additional diagnostic feature is a urinary steroid profile, which shows a decreased ratio for 5α:5α-reduced C₂₁ and C₁₉ steroids. It may not be possible to detect this abnormality in the urine until late infancy. Like 17β–HSD type 3 deficiency, these children can undergo spontaneous virilization during puberty with a rise in testosterone levels, possibly due to increased activity of the type 1 isoenzymes. Thus, early accurate diagnosis of this condition is important as the affected infant may need sex reassignment if initially raised as a girl. Application of topical dihydrotestosterone cream may be a useful test of virilization, as well as help explain the condition to the family.

In XY DSD, a disorder of the androgen receptor (AR) leads to a phenotype that can range from a man with infertility through to a range of abnormalities of the genitalia in the newborn boy (PAIS) to completely female external genitalia (CAIS). Children with AIS should have normal testosterone and dihydrotestosterone response to hCG stimulation and should have a normal urinary steroid profile. However, a number of children with a confirmed genetic diagnosis of AIS may have a poor response to hCG stimulation, and this may be related to associated abnormalities of the testes or the test itself. The AMH level should be normal; sometimes it has been shown to be somewhat high for age-matched standards. Similarly, luteinizing hormone levels may be high especially following LHRH stimulation. There are no müllerian ducts. In the older infant, fixed treatment with testosterone may not be accompanied by changes in testosterone responsive effects, such as a fall in SHBG or change in the size of the phallus. Mutational analysis of the AR gene will provide confirmation of the diagnosis. Androgen binding studies may be helpful in directing mutational analysis, particularly in cases of PAIS. As the condition is inherited in an X-linked pattern, a consistent family history is very helpful. Furthermore, exploration of X-linked markers in affected and nonaffected family members can indicate the likelihood of the condition. A number of cases of XY DSD are incorrectly labelled as ‘PAIS’, when no firm biochemical or genetic abnormalities are identified in gonadal function, androgen synthesis, or androgen action. Strictly speaking, the term PAIS should be reserved for those children who have XY DSD and a genetic abnormality of the AR gene. The children without a genetic abnormality may be better described as ‘XY DSD with a nonspecific disorder of under-masculinization’.

AMH is secreted by the Sertoli cells from around 7 weeks gestation and subsequently acts through the AMH type 2 receptor to lead to regression of the Mullerian ducts. PMDS occurs due to a mutation of the AMH gene or its receptor. In XY infants with PMDS, boys are born with male external genitalia, but have persistence of internal müllerian structures. The diagnosis is usually suspected when a child has a repair of an inguinal hernia, orchidopexy, or coincidental intra-abdominal surgery. There are two anatomic forms. In the commoner type, there is one inguinal hernia, which contains the ipsilateral testis, and the ipsilateral fallopian tube and the uterus. In some of these herniae, the contralateral testis may also be present. In the less common form, all the structures including the testes are present in the pelvis. Affected children have normal testosterone response to hCG, but fertility and, sometimes, Leydig cell function may be compromised in adulthood due to unsuccessful attempts at orchidopexy and anatomical abnormalities of the epididymis and the vas deferens. Surgical opinion about the timing of salpingectomy and hysterectomy vary.

A number of different terminologies (bilateral vanishing testes, embryonic testicular regression, rudimentary testes, congenital anorchia) are used to describe a group of conditions which are characterized in infants with a XY karyotype and absent or rudimentary testes. The syndrome entails the presence of testes which vanish during embryogenesis. The aetiology of this syndrome is unclear: regression of the testes in utero may be due to a genetic mutation, a teratogenic factor, or a bilateral torsion. Clinically, the syndrome encompasses a spectrum of phenotypes, ranging in severity from genital ambiguity to a male phenotype with an empty scrotum. The management of patients with defects of testes maintenance is dictated by their position in the clinical spectrum of the disorder. Patients with rudimentary testes have a male phenotype with micropenis, small atrophic testes with pre-Sertoli and Leydig cells. Some patients present with perineal hypospadias and persistent müllerian derivatives. Congenital anorchia is characterized by the complete absence of testicular tissue at birth, but normal male sexual differentiation without müllerian derivatives.

Unlike the sex categories, male and female, gender has several aspects: gender assignment, gender role, gender identity, gender attribution, and sexuality. In most societies, gender assignment occurs at birth, long before we have a say in the matter, marking the beginning of the process of gender socialization. The process of gender socialization also includes society’s expectations of how males or females should behave, as expressed in their gender role behaviour. Gender identity is distinct from gender role behaviour and refers to the individual’s perception of one’s own gender and how it conforms to the male or female gender role in society. Gender attribution is what we all do when we meet someone and want to decide whether they are a man or a woman. This is often based on obtaining a number of cues that are symbolic manifestations of gender and that have traditionally included clothing, mannerisms, physical appearance, gait, and occupational choice. Finally, sexuality refers to erotic desires, sexual practices, or sexual orientation. In some cultures, individuals are often socially identified as homosexuals or heterosexuals as if a person’s sexual orientation encapsulates the total personality and identity. For most people, their gender identity, gender role, and the symbolic gender manifestations are congruent and, in addition, they will be sexually attracted to the opposite sex. However, it is also possible that a man may have gender manifestations that do not completely converge with his male gender identity and remains sexually attracted to a member of the opposite sex; of course, a number of other permutations may also exist. Some aspects of gender, such as role, assignment, the symbolic manifestations, as well as the different types of sexuality, may differ markedly from one society to another and continue to evolve within respective societies. In some cultures, the distinction is becoming less absolute and it may be better to consider these aspects as a continuum, with female characteristics at one extreme and male ones at the other. The development of gender identity is the result of a complex interaction between genetic, prenatal, and postnatal endocrine influences, and postnatal psychosocial and environmental experiences. Gender development consists of gender identity formation, such as gender knowledge, self-perception, preferences (toy, playmate), and gender role behaviours (27). By the end of the first year of life, infants may already be able to discriminate between the sexes, and some may be able to display sex-related toy preferences. By 2–3 years of age children are able to correctly label themselves and others according to gender. By the age of 3 years, preference for one sex role has emerged with the child having a clear sense of whether he/she is a boy or girl. Children fix on cues, such as clothing and hair in gender labelling exercises; even when genital cues are available they are used far less to make categorization decisions than these other cues, at least until the age of 8 years or so, possibly reflecting insufficient biological understanding of gender differences. By the age of 5 years, children learn that gender remains stable over time, becoming preoccupied with categorical differences between males and females. However, it is not until children have mastered the concept that gender remains constant (despite superficial changes in appearance), at the age of between 5 and 7, that many argue is when a gender identity has been fully attained. Theorists have suggested that once 'gender constancy' has been mastered, this becomes a motivator to shaping sex appropriate gender behaviour (28).

Initial gender uncertainty is unsettling and stressful for families, as well as the health professionals. Given that gender development is a relatively long-term process, clinical professionals involved in management need to be clear of the distinction between sex assignment and gender assignment; the latter cannot be achieved by the clinical team, and should be considered intrinsic to the child’s own development. However, expediting a thorough assessment and reaching a decision on sex assignment is required. Factors that influence sex assignment include the diagnosis, genital appearance, surgical options, need for lifelong replacement therapy, the potential for fertility, views of the family, and sometimes circumstances relating to cultural practices. More than 90% of 46,XX CAH patients and all 46XY CAIS assigned female in infancy identify as females. Evidence supports the current recommendation to raise markedly virilized 46,XX infants with CAH as female. In the late presenting virilized 46,XX child who has been raised as a boy, there are cases where gender reassignment has not been undertaken and there is a need for long-term outcome studies in these cases, as well as those where gender reassignment has occurred (29). Approximately, 60% of 5α-reductase (5αRD2) deficient patients assigned female in infancy and virilizing at puberty (and all assigned male) live as males. In 5αRD2 and possibly 17β-hydroxysteroid dehydrogenase (17β-HSD3) deficiencies, where the diagnosis is made in infancy, the combination of a male gender identity in the majority and the potential for fertility (documented in 5αRD2, but unknown in 17β-HSD3) should be discussed when providing evidence for gender assignment. Among patients with PAIS, androgen biosynthetic defects, and incomplete gonadal dysgenesis, there is dissatisfaction with the sex of rearing in about 25% of individuals whether raised male or female. Available data supports male rearing in all patients with micropenis, taking into account equal satisfaction with assigned gender in those raised male or female, but no need for surgery, and the potential for fertility in patients reared as male. The decision on sex of rearing in ovotesticular DSD should consider the potential for fertility based on gonadal differentiation and genital development, and assuming the genitalia are, or can be made consistent with the chosen sex. In the case of mixed gonadal dysgenesis (MGD), factors to consider include prenatal androgen exposure, testicular function at and after puberty, phallic development, and gonadal location. Individuals with cloacal exstrophy reared female show variability in gender identity outcome, but more than 65% appear to live as women.

The surgeon has a responsibility to outline the surgical sequence and subsequent consequences from infancy to adulthood. Only surgeons with expertise in the care of children and specific training in the surgery of DSD should perform these procedures. Parents now appear to be less inclined to choose surgery. As orgasmic function and erectile sensation may be disturbed by clitoral surgery, the surgical procedure should be anatomically based to preserve erectile function and the innervation of the clitoris Emphasis should be placed more on functional outcome, rather than a strictly cosmetic appearance. It is generally felt that surgery that is performed for cosmetic reasons in the first year of life relieves parental distress, and improves attachment between the child and the parents. However, systematic evidence for this belief is lacking. It is anticipated that surgical reconstruction in infancy will need to be refined at the time of puberty. Vaginal dilatation should not be undertaken before puberty. The surgeon must be familiar with a number of operative techniques in order to reconstruct the spectrum of urogenital sinus disorders. An absent or inadequate vagina (with rare exceptions) requires a vaginoplasty in adolescence when the patient is psychologically motivated and a full partner in the procedure. In the case of a DSD associated with hypospadias, standard techniques for surgical repair include chordee correction, urethral reconstruction, and the judicious use of testosterone supplementation. The magnitude and complexity of phalloplasty in adulthood should be taken into account during the initial counselling period. It should also be explained to parents that sexual contentment is not simply dependent on penetrative sex. Parents must not be given unrealistic expectations about penile reconstruction, including the use of tissue engineering. The testes in patients with CAIS and those with PAIS, raised female, need to be removed to prevent malignancy in adulthood, but this can be deferred until adolescence, which allows spontaneous feminization and an opportunity for the patient to have a say in the timing of removal. The streak gonad in a patient with MGD raised male should be removed in early childhood. Bilateral gonadectomy is performed in early childhood in females (bilateral streak gonads) with gonadal dysgenesis and Y chromosome material. In patients with androgen biosynthetic defects raised female, gonadectomy should be performed before puberty. A scrotal testis in patients with gonadal dysgenesis remains at risk for malignancy and there is little consensus on screening besides regular palpation in adolescence and adulthood.

Psychosocial care should be an integral part of management in order to promote positive adaptation, and allow parents to express and resolve their concerns. Whilst the mental health care staff should have some knowledge about DSD, in most cases, the early concerns of parents may be less to do with the long-term implications of the condition and more to do with coping and adjustment of the parents during early infancy and some of these issues are generic to many stressful neonatal situations (Table 7.1.4.2). Health care staff with this experience and who work as part of a clinical network, where they have access to others with more specialist knowledge and experience may be particularly valuable in providing generic psychosocial support. A common issue seems to be related to how the condition should be explained to friends and relatives (6). This expertise can facilitate team decisions about gender assignment/reassignment, timing of surgery, and sex hormone replacement. Psychosocial screening tools that identify families at risk for maladaptive coping with a child’s medical condition should be considered. It should be explained to the new parents that it is routine practice to involve mental health staff and that they will have access to these staff throughout the child’s development. Once the child is sufficiently developed for a psychological assessment of gender identity, such an evaluation must be included in discussions about gender reassignment. Gender identity development begins before the age of 3 years, but the earliest age at which it can be reliably assessed remains unclear. The generalization that the age of 18 months is the upper limit of imposed gender reassignment should be treated with caution and viewed conservatively. Atypical gender role behaviour is more common in children with DSD than in the general population, but should not be taken as an indicator for gender reassignment. It is important to emphasize the separability of sex-typical behaviour, sexual orientation, and gender identity. Thus, homosexual orientation (relative to sex of rearing) or strong cross-sex interest in an individual with DSD is not an indication of incorrect gender assignment. In the longer-term, most current studies suggest that affected individuals lead productive lives but a small proportion may have functional problems and may also suffer from gender identity disorders (30). Parents do need to be aware of these issues. The parents should be explained that the process of disclosure concerning facts about karyotype, gonadal status and prospects for future fertility is a collaborative ongoing action, which requires a flexible individual-based approach. It should be planned with the parents from the time of diagnosis. Medical education and counselling for children, as well as the parents shall be a recurrent gradual process of increasing sophistication which is commensurate with changing cognitive and psychological development.