The haplotypes of seven Y-chromosome STR loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) were determined in a sample of 634 healthy Brazilian males (190 adult individuals and 222 father-son pairs). The 412 adults were unrelated, and the 222 father-son pairs had their biological relationship confirmed using autosomal STRs (LR > 10,000). Among the 412 adults, a total of 264 different 7-loci haplotypes were identified, 210 of which were unique. The most frequent haplotype was detected in 31 instances, occurring with a frequency of 7.52%. The haplotype diversity index was calculated as 98.83%. Upon transmission of the 1,554 alleles, in 222 father-son pairs, six mutations were observed, with an average overall rate of 3.86 x 10-3 per locus. A haplotype with a duplicated DYS389I locus, and another with duplicated DYS389I, DYS389II, and DYS439 loci were detected in both fathers and their respective sons.

A síndrome de insensibilidade aos andrógenos é uma doença rara ligada ao X, causada por mutações no gene do receptor androgênico (AR), associada a uma variedade de fenótipos em indivíduos 46,XY. Avaliamos duas irmãs gêmeas de 23 anos com sexo social feminino encaminhadas por amenorréia primária, e que apresentavam gônadas palpáveis na região inguinal e cariótipo 46,XY. A ultra-sonografia pélvica não evidenciou útero. As dosagens basais revelaram concentrações elevadas de LH (35 e 42U/L), normais de FSH (7,9 e 7,8U/L) e altas de testosterona (1330 e 1660ng/dl). O estudo molecular identificou uma rara mutação missense no exon 5 do gene do AR com a troca de uma prolina por uma alanina na posição 766 da proteína. O aminoácido prolina 766 do AR é altamente conservado entre as espécies e situa-se em região correspondente ao domínio de ligação ao andrógeno.

Androgen insensitivity syndrome (AIS) is a rare X-linked disorder, caused by mutations in the androgen receptor gene (AR), associated with a variety of phenotypes in 46,XY individuals. We studied two 23 year-old twin-sisters with female social sex referred due to primary amenorrhea, who exhibited bilateral palpable gonads in the inguinal region and a 46,XY karyotype. The uterus was absent in pelvic sonograms. Basal LH levels were elevated (35 and 42U/L), with normal FSH (7.9 and 7.8U/L) and high testosterone levels (1330 and 1660ng/dl). The molecular analysis identified a missense mutation in exon 5 of AR gene that changed a proline to an alanine at position 766 of the protein. Proline 766 is a highly conserved amino acid in the AR of several species and is located in the androgen binding domain.