RESUMO
To determine the mechanism for the coexistence of XX chromosomal maleness and true hermaphroditism in the same family, we performed cytogenetic and molecular genetic analyses, using DNA probes from the short arm of the Y chromosome. These studies excluded the following possible mechanisms: (1) an inherited, mitotically unstable Y chromosome that results in chromosomal mosaicism, (2) an inherited Y-to-X or Y-autosomal translocation, (3) recurrent Y-to-X translocation, and (4) incomplete inactivation of the X chromosomal homolog for the testicular determining factor. We conclude that the disorder of sexual differentiation observed in this family can be best explained by a dominant autosomal gene with variable expressivity.
Assuntos
Transtornos do Desenvolvimento Sexual/genética , Aberrações dos Cromossomos Sexuais/genética , Translocação Genética , Cromossomo X , Cromossomo Y , Southern Blotting , Mapeamento Cromossômico , DNA/análise , Sondas de DNA , Feminino , Humanos , Masculino , LinhagemRESUMO
Reported here is a family with which 46,XX males and 46,XX true hermaphrodites coexist. The propositus was a paternal uncle with 46,XX true hermaphroditism. One of his brothers fathered a 46,XX daughter with true hermaphroditism; a second brother fathered two 46,XX males. Both fathers have normal male karyotypes and phenotypes. No evidence for chromosomal mosaicism or any additional chromosomal abnormalities was obtained. We conclude that inheritance of the abnormality is most likely via paternal transmission of an autosomal testis-determining factor. This family provides evidence to support the hypothesis that 46,XX true hermaphrodites and 46,XX males represent alternative manifestations of the same genetic defect.