Essential for spermiogenesis and male fertility (By similarity). Involved in the formation of sperm acrosome during spermatogenesis. Shift from Golgi to sperm acrosome. Expressed in testis. The disease is caused by variants affecting the gene represented in this entry. An autosomal recessive variation of SPATA16 has been shown to be responsible for the disease in a consanguineous family with members homozygous for the variation. Association analysis reveals significant frequency of a synonymous (Ser-225) sequence polymorphism among clinical groups with different sperm traits: the donor group, which has the highest sperm count and motility level, has a significant higher polymorphism frequency compared to normal and asthenozoopermia groups. Belongs to the SPATA16 family.