Clinical and molecular characterization of a cohort of 161 unrelated women with nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency and 330 family members.

CONTEXT: Nonclassical congenital adrenal hyperplasia (NC-CAH) due to partial 21-hydroxylase deficiency is one of the most frequent autosomal recessive diseases. OBJECTIVE: The aim of this study was to determine the genotype/phenotype relationship in probands and family members. PATIENTS AND METHODS: A total of 161 NC-CAH unrelated women diagnosed on late-onset symptoms, mainly hirsutism, and post-ACTH 17-hydroxyprogesterone more than 10 ng/ml, and 330 of their relatives was explored. CYP21A2 was genotyped in 124 probands. RESULTS: The most frequent mutation was V281L. One severe mutation was found in 63.7% of probands, and surprisingly two severe mutations in four probands. Contrasting with the absence of clinical differences, basal testosterone, and androstenedione, basal and post-ACTH 17-hydroxyprogesterone were significantly higher in probands carrying at least one severe mutation than in those with two mild mutations (P < 0.01). Among the 330 family members, 51 were homozygotes or compound heterozygotes, and 42 were clinically asymptomatic; 242 were heterozygotes and 37 unaffected. Post-ACTH 21-deoxycortisol (21dF) was significantly higher in heterozygotes than in unaffected, however, an overlap existed. In 12 heterozygotes, post-ACTH 21dF was below 0.55 ng/ml, the cutoff value usually accepted for suggesting heterozygosity. CONCLUSIONS: The study of family members underlines the variable expression of NC-CAH even within a family, suggesting that modifier factors may modulate phenotype expression. Post-ACTH 21dF cannot reliably detect heterozygous subjects. Considering the high frequency of heterozygotes in the general population, it is essential to genotype the partner(s) of the patients with one severe mutation to offer genetic counseling.

Aetiological diagnosis of male sex ambiguity: a collaborative study.

UNLABELLED: A collaborative study, supported by the Biomed2 Programme of the European Community, was initiated to optimise the aetiological diagnosis in genetic or gonadal males with intersex disorders, a total of 67 patients with external sexual ambiguity, testicular tissue and/or a XY karyotype. In patients with gonadal dysgenesis or true hermaphroditism, the incidence of vaginal development was 100%, a uterus was present in 60%; uni or bilateral cryptorchidism was seen in nearly all cases of testicular dysgenesis (99%) but in only 57% of true hermaphrodites. Mean serum levels of anti-mullerian hormone and of serum testosterone response to chorionic gonadotropin stimulation were significantly decreased in both conditions, by comparison with patients with unexplained male pseudohermaphroditism or partial androgen insensitivity (PAIS). Mutations in the androgen receptor, 90% within exons 2-8, were detected in patients with PAIS. Clinically, a vaginal pouch was present in 90%, cryptorchidism in 36%. In 52% of cases, no diagnosis could be reached, despite an exhaustive clinical and laboratory work-up, including routine sequencing of exons 2-8 of the androgen receptor. By comparison with PAIS, unexplained male pseudohermaphroditism was characterised by a lower incidence of vaginal pouch (55%) and cryptorchidism (22%) but a high incidence of prematurity/intrauterine growth retardation (30%) or mild malformations (14%). CONCLUSION: reaching an aetiological diagnosis in cases of male intersex is difficult because of the variability of individual cases. Hormonal tests may help to discriminate between partial androgen insensitivity and gonadal dysgenesis/true hermaphroditism but are of less use for differentiating from unexplained male pseudohermaphroditism. Sequencing of exons 2-8 of the androgen receptor after study of testosterone precursors following human chorionic gonadotrophin stimulation is recommended when gonadal dysgenesis and true hermaphroditism can be excluded.