eLife assessment
This study provides useful information on the function of a ciliary and flagellar-associated protein, CFAP52, in the assembly of sperm head-tail connecting apparatus (HTCA) and tail formation in humans and mice. The significance is to identify CFAP52 as a genetic factor for asthenoteratozoospermia with a mixed acephalic spermatozoa syndrome (ASS) and multiple morphological abnormalities of the sperm flagella (MMAF) phenotype. The strength of the study is that the experimental evidence using CFAP52 loss-of-function in mice is solid to support that CFAP52 is essential for sperm motility and male fertility by contributing to HTCA and 9+2 axoneme, corroborating the sperm phenotypes of human patients with compound heterozygous mutations in CFAP52.