Background: The XX male syndrome Testicular Disorder of Sexual Differentiation (DSD) is a rare condition characterized by a spectrum of clinical presentations, ranging from ambiguous to normal male genitalia. The project Genetics of Human Disorders of Sexual Development is funded by Swiss National Science Foundation and fulfilled by the University of Geneva Medical School, the Medical Centers from Armenia, Poland and Ukraine. The goal is to identify mutations underlying unresolved DSD phenotypes in novel DSD genes, or regulatory regions that lead to atypical gene expression. During 2 years Armenian part collected four patients with SRY-positive 46,XX. The physical examination included the measurement of height, potential gynecomastia and the inspection of external sex organs. Bilateral volume was calculated as the sum of the volume of both testes. Serum levels of testosterone and anti-Müllerian hormone (AMH) were assessed. Genomic DNA from peripheral blood of the patients using QIAamp DNA Blood Kits was extracted. The three discrete regions, AZFa, AZFb and AZFc, located on the long arm of the Y chromosome, were performed by multiplex PCRs amplification. The set of PCR primers for the diagnosis of microdeletion of the AZFa, AZFb and AZFc region included: sY84, sY86, sY127, sY134, sY254, sY255, SRY and ZFX/ZFY.
Results: Our research reported that four patients had a female karyotype but were phenotypically male (46,XX males) and two of them were twins. They had normal external genitalia and masculinization, all males were SRY-positive, which translocated on the short arm of X chromosome, and absent of the spermatogenic factors encoding gene on Yq, such as AZFa, AZFb and AZFc region in Y chromosome. Endocrinological data indicated that the patients had a lower testosterone and a low level of AMH.
Conclusion: Our reports adds cases on the four new 46,XX male individuals with sex reversal and further verifies the view that the presence of SRY gene and the absence of major regions in Y chromosome should lead to the expectance of a completely masculinised phenotype, abnormal hormone levels and infertility.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology