Novel NLRP14 Mutations Induce Azoospermia

Abstract

Background. LR family pyrin domain-containing 14 (NLRP14 or NALP14) is one of the important members of the NLR family and was mainly expressed in testis. It is reported that deficiency in the NALP14 gene in mice can cause spermatogenic failure, and several NALP14 mutations have been found in oligospermia and infertile men. Case Presentation. This study reported two novel NALP14 mutations (c.2076delC: p.L697X and c.T2963C: p.F988S) in our patients with azoospermia. The exonic deletion mutation (c.2076delC) and one missense mutation (c.T2963C) were firstly screened out by whole-exome sequencing (WES) and further verified by amplifying and sequencing the specific exons 5 and 10. Histological analysis of testicular biopsy revealed that NALP14 expression was detected strongly in spermatogonia and weakly in early spermatocytes. Additionally, mutations in this gene caused meiotic arrest, and no postmeiotic round spermatids and mature spermatozoa were observed in the seminiferous tubules. Conclusions. This study and previous literatures showed that NLRP14 mutations are closely related to male infertility; we discovered two novel NALP14 mutations and summarized the kinds of literatures on NLRP14 mutations and male infertility. This is the first report that deletion mutation (c.2076delC) and one missense mutation (c.T2963C) in NALP14 all lead to azoospermia, which is still significant to the clinical auxiliary diagnosis of male infertility.

Investigating the role of a testis-expressed gene Tex2 in spermatogenesis in mice

“…In addition to Tex2, knockout of Tex33, Tex36, or Tex37 also leaves fertility unaffected, supporting that the functional compensation effect in the Tex gene family [30,31]. Indeed, several genes, including Tex11, Tex12, Tex14, Tex15, Tex17, Tex18 and Tex40, are essential in spermatogenesis, and deletion of which results in mouse infertility or subfertility, respectively [32,33]. Therefore, these genes play a crucial role in spermatogenesis, thereby compensating for the absence of certain genes, such as Tex2, and enabling knockout mice to maintain normal fertility.…”

Histological patterns of testicular biopsy in patients with azoospermia: single-institution experience

“…Azoospermia affects 10-15% of men experiencing infertility, and it is defined as a total lack of sperm cells in the semen. Depending on the presence of the obstruction in the extratesticular excurrent ducts, it is classified into obstructive (OA) and non-obstructive azoospermia (NOA), where 60% of cases are attributed to NOA [2,3].…”