Clinical and molecular analysis of XX sex reversed patients

Abstract

Purpose: The XX male syndrome presents with a spectrum of clinical appearances from phenotypic male individuals to true hermaphrodites. Previous reports established the sex determining region of the Y chromosome (SRY) gene as the testis determining factor. However, a subset of XX sex reversed male individuals exists without a translocation of SRY deoxyribonucleic acid (DNA) material to the X chromosome. In addition to clinical or endocrinological criteria, Y DNA probe studies, and radiological and surgical evaluation as indicated are necessary for an accurate diagnosis.

Materials and methods: We evaluated 5 XX sex reversed patients (2 true hermaphrodites and 3 male individuals) by physical examination, pedigree analysis, endocrinological testing, molecular analysis of Y DNA, radiological studies and surgery (exploration and/or biopsy).

Results: All patients were SRY gene negative. Two patients were siblings. Complete endocrinological testing was negative in all cases. Two patients had a normal male phenotype. Radiological findings confirmed by cystoscopy or laparoscopy revealed a utricle, vesicoureteral reflux, and cervix and uterus in various patients. Gonadal biopsy showed ovotestes or ovary and testis in the 2 true hermaphrodites. The 3 XX male individuals had normal immature testes on biopsy.

Conclusions: Categories of XX sex reversal include classic XX male individuals with normal phenotypes, nonclassic XX male individuals with sexual ambiguity and XX true hermaphrodites. Simple translocation of the SRY gene to the X chromosome does not always account for testicular differentiation and a male phenotype. The masculinization of our patients in the absence of SRY suggests an alteration of 1 or more downstream Y, X or autosomal testis determining genes. We present another theory for male sex determination, including a downstream gene on the X chromosome in which expression is influenced by X inactivation. Y DNA genomic analysis, radiological studies and laparoscopic evaluation with gonadal biopsy as appropriate are recommended for complete assessment and treatment of these intersex patients.