A novel homozygous nonsense variant of STX2 underlies non-obstructive azoospermia in a consanguineous Chinese family.

Male infertility is a widespread population health concern, causing various degrees of adverse fertility outcomes. We determined the genetic cause of an infertile male from a consanguineous family, expanding the mutant spectrum of male infertility. A non-obstructive azoospermia (NOA) patient was recruited, and histological type of human testicular tissue of the patient categorized as maturation arrest. We identified a novel loss-of-function variant of syntaxin 2 (STX2) (c.142C>T:p.Gln48*) by performing Whole-exome sequencing (WES) on the NOA patient from a consanguineous Chinese family. Sanger sequencing confirmed the p.Gln48* variant was maternally and paternally inherited. The variant was predicted to be deleterious and resulted in aberrant changes to structure and function of STX2 by In silico analysis. In summary, we reported for the first time that a nonsense variant occurred in the exon region of STX2 in an infertile male presenting with NOA, which was beneficial for diagnosis and therapies of NOA.