A homozygous CEP135 mutation is associated with multiple morphological abnormalities of the sperm flagella (MMAF).

Multiple morphological abnormalities of the sperm flagella (MMAF) is a rare disease associated with primary infertility; however, ~50% of the genetic alterations associated with MMAF remain unclear. Here, we reported the case of a 30-year-old infertile male from a consanguineous family. Whole-exome sequencing identified a homozygous mutation in the CEP135 gene (c.A1364T:p.D455V), with CEP135 previously reported to play a role in centriole biogenesis and specifically central pair assembly. D455V-mutated proteins formed protein aggregates in the centrosome and the flagella, which might potentially affect the function of centriole assembly. Moreover, intracytoplasmic sperm injection was performed using sperm from this patient; however, pregnancy failed following embryo transfer. This represents the first report of a homozygous mutation of CEP135 associated with MMAF. These results provide researchers and clinicians with a deeper understanding of the gene involved with MMAF and will help predict and assess pregnancy outcomes associated with in vitro fertilization.