Global gene profiling and comprehensive bioinformatics analysis of a 46,XY female with pericentric inversion of the Y chromosome

Ontogenic and morphological study of gonadal formation in genetically-modified sex reversal XY(POS) mice

Mammalian sexual fate is determined by the presence or absence of sex determining region of the Y chromosome (Sry) in the “bipotential” gonads. Recent studies have demonstrated that both male and female sexual development are induced by distinct and active genetic pathways. Breeding the Y chromosome from Mus m. domesticus poschiavinus (POS) strains into C57BL/6J (B6J) mice (B6J-XY^POS) has been shown to induce sex reversal (75%: bilateral ovary, 25%: true hermaphrodites). However, our B6N-XY^POS mice, which were generated by backcrossing of B6J-XY^POS on an inbred B6N-XX, develop as males (36%: bilateral testis with fertility as well as bilateral ovary (34%), and the remainder develop as true hermaphrodites. Here, we investigated in detail the expressions of essential sex-related genes and histological features in B6N-XY^POS mice from the fetal period to adulthood. The onsets of both Sry and SRY-box 9 (Sox9) expressions as determined spatiotemporally by whole-mount immunohistochemistry in the B6N-XY^POS gonads occurred 2–3 tail somites later than those in B6N-XY^B6 gonads, but earlier than those in B6J-XY^POS, respectively. It is possible that such a small difference in timing of the Sry expression underlies testicular development in our B6N-XY^POS. Our study is the first to histologically show the expression and ectopic localization of a female-related gene in the XY^POS testes and a male-related gene in the XY^POS ovaries. The results from these and previous experiments indicate that the interplay between genome variants, epigenetics and developmental gene regulation is crucial for testis development.

A rare cause of primary amenorrhoea, the XY female with gonadal dysgenesis

Disorders of sexual development are conditions where sexual phenotype and genotype are discordant. Genetic sex is determined at conception as the ovum is fertilised by a spermatozoon that contains either an X or Y chromosome. A complex pathway determined by genes and hormones leads to gonadal differentiation into testis or ovary and promotes the development of internal and external genitalia. We present a case of an 18-year-old woman who presented with primary amenorrhoea. She was a virgin, and apart from hirsutism and overweight, had no complaints. Her family history was insignificant. The patient was tall and had underdeveloped breasts. Her blood results showed hypergonadotropic hypogonadism. A 46, XY genotype was detected with karyotype analysis. Ultrasound and MRI demonstrated the presence of a uterus, but no overt gonads. Laparoscopy was performed, with bilateral removal of streak ovaries.