Clinical, cytogenetic, and molecular analysis with 46,XX male sex reversal syndrome: case reports.

Purpose: To investigate the clinical characteristics of different categories of sex-reversed 46,XX individuals and their relationships with chromosomal karyotype and the SRY gene.

Methods: Chromosome karyotyping for peripheral blood culture and multi-PCR and FISH were performed.

Results: Endocrinological data showed that their endocrine hormone levels were similar to that observed for Klinefelter syndrome, with higher FSH and LH levels and lower T levels. Chromosome karyotyping for peripheral blood culture revealed 46, XX complement for 11 males. Molecular studies showed that there were locus deletions at SY84, SY86, SY127, SY134, SY254 and SY255 in AZF on chromosome Y in 9 cases, with the SRY gene present at the terminus of the X chromosome short arm. In one case, besides 6 locus deletions in AZF, there was also SRY gene deletion. In another case, there were locus deletions only at SY254 and SY255, with SY84, SY86, SY127 SY134 loci and SRY present.

Conclusions: The majority (10/11) of 46,XX males were SRY positive, with the SRY gene translocated into the terminus of the X chromosome short arm. These patients were caused mainly by an X/Y chromosomal inter-change during paternal meiosis, leading to the differentiation of primary gonads into testes. Only a single patient (1/11) was SRY-negative, in which there might be some unknown downstream genes involved in sex determination.