A homozygous loss-of-function mutation in CEP250 is associated with acephalic spermatozoa syndrome in humans.

Background: The presence of predominantly headless sperm in semen is a hallmark of acephalic spermatozoa syndrome, which is primarily caused by gene mutations in humans.

Purpose: To identify genetic causes for acephalic spermatozoa syndrome.

Methods: Polymerase chain reaction and Sanger sequencing were performed to define mutations in SUN5 and PMFBP1. Whole-exome sequencing was performed on the patients to identify pathogenic mutations for infertility. Western blotting and immunofluorescence analysis detected the expression level and localization of CEP250. Co-immunoprecipitation detected the protein-protein interactions. Cep250-KI mice were generated by the CRISPR-Cas9 system.

Results: Here, 10 patients diagnosed with acephalic spermatozoa syndrome were recruited, and a homozygous loss-of-function mutation in CEP250 (NM_007186: c. 4710_4723del: p. E1570fs*39) was identified from a consanguineous Han Chinese family. Immunofluorescence experiments revealed a decreased CEP250 signal in the neck region of the patient's sperm compared with the normal. Co-immunoprecipitation results indicated reduced interaction between SUN5/PMFBP1 and mutant CEP250 compared with the wild-type, possibly due to the absence of complete 2272-2442 amino acids. Besides, the patient can be effectively treated with intracytoplasmic sperm injections. Nevertheless, Cep250-KI male mice exhibit non-obstructive azoospermia, which indicates the different functions in CEP250 between human and mouse spermatogenesis.

Conclusion: Collectively, CEP250 may represent a novel pathogenic gene for acephalic spermatozoa syndrome in humans, and we provide precise genetic diagnosis and treatment strategies for the patient.