Elaine M.F. Costa

Most of the patients with 5α-RD 2 deficiency are reared in the female social sex due to their severely undervirilized external genitalia but ~60% who have not been submitted to orchiectomy in childhood undergo male social sex change at puberty. In our cohort of 30 cases from 18 families, all subjects were registered in the female social sex except for two children—one who had an affected uncle and the other who was diagnosed before being registered. The majority of the patients were satisfied with the long-term results of their treatment and surprisingly, penile length was not associated with satisfactory or unsatisfactory sexual activity. Steroid 5α-RD2 deficiency should be included in the differential diagnosis of all newborns with 46,XY DSD with normal testosterone production before gender assignment or any surgical intervention because these patients should be considered males at birth.

A síndrome de insensibilidade aos andrógenos (AIS) é uma doença com herança ligada ao cromossomo X que afeta pacientes com cariótipo 46,XY, nos quais há prejuízo total (forma completa, CAIS) ou parcial (PAIS) do processo de virilização intra-útero devido à alteração funcional do receptor de andrógenos (AR). Apresentamos uma revisão da AIS e do AR com os dados clínicos, hormonais e moleculares de 33 casos. Analisamos a região codificadora do gene do AR em 33 pacientes de 21 famílias, com quadro clínico e hormonal sugestivo de AIS. Onze pacientes (9 famílias) com diagnóstico de CAIS e 22 pacientes (12 famílias) com diagnóstico de PAIS. Identificamos mutações no gene do receptor androgênico e a etiologia da síndrome de insensibilidade aos andrógenos em 86% das 21 famílias estudadas: 100% das famílias com insensibilidade completa aos andrógenos e 75% das famílias com insensibilidade parcial aos andrógenos. Identificamos 9 mutações no AR descritas anteriormente na literatura (N705S, W741C, M742V, R752X, Y763C, R779W, M807V, R855C e R855H) e 7 mutações foram descritas pela primeira vez nesta casuística (S119X, T602P, L768V, R840S, I898F, P904R e IVS3 - 60 G>A).

Mutations of the androgen receptor gene causing androgen insensitivity syndrome in 46, XY individuals, result in phenotypes ranging from complete female to ambiguous genitalia to males with minor degrees of undervirilization. We studied two Brazilian brothers with partial androgen insensitivity syndrome. They were born with perineal hypospadias, bifid scrotum, small penis and cryptorchidism, and developed gynecomastia at puberty. Genomic DNA was extracted and denaturinggradient gel electrophoresis of exon 7 of the androgen receptor gene followed by sequence analysis revealed a new mutation, a C A transversion, altering codon 840 from arginine (CGT) to serine (AGT). R840 is located in the androgen binding domain, in a “hot spot” region, important for the formation and function of the hormone receptor-complex and within the region that is involved in androgen receptor dimerization. Replacement of arginine (basic) by serine (neutral and polar) is a nonconservative substitution. Three mutations in this residue (R840C, R840G nonconservative and R840H, conservative) were previously reported in patients with partial androgen insensitivity syndrome and when expressed “in vitro” lead to a subnormal transactivation of a reporter gene. We conclude that the novel R840 mutation in the androgen receptor is the cause of partial androgen insensitivity syndrome in this Brazilian family. Hum Mutat 14:353, 1999.