Novel inactivating mutations of the DCAF17 gene in American and Turkish families cause male infertility and female subfertility in the mouse model.

Loss-of-function DCAF17 variants cause hypogonadism, partial alopecia, diabetes mellitus, mental retardation, and deafness with variable clinical presentation. DCAF17 pathogenic variants have been largely reported in the Middle Eastern populations, but the incidence in American families is rare and animal models are lacking. Exome sequencing in 5 women with syndromic hypergonadotropic hypogonadism from 2 unrelated families revealed novel pathogenic variants in the DCAF17 gene. DCAF17 exon 2 (c.127-1G > C) novel homozygous variants were discovered in 4 Turkish siblings, while 1 American was compound heterozygous for 1-stop gain variant in exon 5 (c.C535T; p.Gln179*) and previously described stop gain variant in exon 9 (c.G906A; p.Trp302*). A mouse model mimicking loss of function in exon 2 of Dcaf17 was generated using CRISPR/Cas9 and showed female subfertility and male infertility. Our results identify 2 novel variants, and show that Dcaf17 plays a significant role in mammalian gonadal development and infertility.

Neurokinin B signalling in human puberty.

Recent identification of TAC3 or TACR3 (encoding neurokinin B and its receptor, NK3R, respectively) mutations as the causes of normosmic idiopathic hypogonadotrophic hypogonadism has provided compelling evidence for the involvement of neurokinin B (NKB) signalling in puberty. A surge of subsequent studies pointing towards an understanding of the exact mechanism through which NKB signalling exerts its effects in puberty led to a postulated sketch of the GnRH pulse generator, in which kisspeptin, NKB and dynorphin work in concert to elicit pulsatile gonadotrophin-releasing hormone release in the median eminence.