Correlation of the abundance of mutant alleles with the pathological abnormalities in ovarian tissue from a young girl with McCune–Albright syndrome and precocious puberty. A cross-section from a paraffin-embedded section of ovary from a patient (patient 1 in (22)) with McCune–Albright syndrome is shown in the centre (× 50). The two outlined areas, shown at × 120, were dissected and analysed independently; area A shows ovarian cortex containing primordial follicles, and area B shows follicular cyst lining containing stimulated luteinized theca. On the right are blots showing the results of allele-specific oligonucleotide hybridization of DNA with wild type (R201) or mutant (R201C) radioactively labelled primers after PCR amplification; DNA was isolated from total ovary (centre) or specific regions as shown. (From Weinstein LS, Shenker A, Gejman PV, Merino MJ, Friedman E, Spiegel AM. Activating mutations of the stimulatory G protein in the McCune-Albright syndrome. N Engl J Med, 1991; 325: 1688–95 (22).)