Skewed X-chromosome inactivation pattern in SRY positive XX maleness: a case report and review of literature.
XX maleness is the most common condition in which testes develop in the absence of a cytogenetically detectable Y chromosome. Using fluorescence in situ hybridization (FISH) or PCR, it was possible to detect the transfer of Yp fragments including SRY gene to the terminal part of X chromosome in the majority of XX males. We report a 32-year-old-male in whom a seminal analysis showed azoospermia, an X chromatin analysis showed 44% of Barr body positive nuclei and a chromosomal analysis revealed a 46,XX karyotype. Physical examination showed a normal sexual development and bilateral small testes. Hormonal studies revealed hypergonadotropic hypogonadism. Testis histological examination showed a profile of Sertoli Only Cell Syndrome. FISH study ruled out the presence of a Y-bearing cell line, and confirmed translocation of SRY to Xp terminal part. In order to confirm that the complete masculinized phenotype was related to a preferential inactivation of the no rearranged X chromosome, X-chromosome inactivation patterns (XCIP) were studied by analysis of methylation status of the androgen receptor gene. Highly skewed XCIP was observed by greater than 90% preferential inactivation involving one of the two X chromosomes, suggesting that the SRY-bearing X chromosome was the preferentially active X allowing for sufficient SRY expression for complete masculinization.
Bouayed Abdelmoula
Nouha
N
Laboratoire d'Histologie Embryologie, Faculté de Médecine de Sfax, Avenue Magida Boulila, CP 3029, Sfax, Tunisia. nouha_abdelmoulabouayed@yahoo.fr <nouha_abdelmoulabouayed@yahoo.fr>
Portnoi
Marie-France
MF
Keskes
Leila
L
Recan
Dominique
D
Bahloul
Ali
A
Boudawara
Tahia
T
Saad
Ali
A
Rebai
Tarek
T
D000328:Adult; D041321:Chromosomes, Human, X; D019175:DNA Methylation; D012734:Disorders of Sex Development / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D024282:Genes, sry; D006801:Humans; D007621:Karyotyping; D008297:Male; D009845:Oligospermia / Q000235:genetics; D011944:Receptors, Androgen / Q000235:genetics* / Q000378:metabolism; D012661:Semen / Q000378:metabolism*; D019849:Sex Determination Processes; D013577:Syndrome
D011944:Receptors, Androgen