Background The genetic causes for most male infertility due to severe oligoasthenoteratozoospermia (OAT) remain unclear.
Objective To identify the genetic cause of male infertility characterised by OAT.
Methods Variant screening was performed by whole-exome sequencing from 325 infertile patients with OAT and 392 fertile individuals. In silico and in vitro analyses were performed to evaluate the impacts of candidate disease-causing variants. A knockout mouse model was generated to confirm the candidate disease-causing gene, and intracytoplasmic sperm injection (ICSI) was used to evaluate the efficiency of clinical treatment.
Results We identified biallelic CFAP61 variants (NM_015585.4: c.1654C>T (p.R552C) and c.2911G>A (p.D971N), c.144–2A>G and c.1666G>A (p.G556R)) in two (0.62%) of the 325 OAT-affected men. In silico bioinformatics analysis predicted that all four variants were deleterious, and in vitro functional analysis confirmed the deleterious effects of the mutants. Notably, H&E staining and electron microscopy analyses of the spermatozoa revealed multiple morphological abnormalities of sperm flagella, the absence of central pair microtubules and mitochondrial sheath malformation in sperm flagella from man with CFAP61 variants. Further immunofluorescence assays revealed markedly reduced CFAP61 staining in the sperm flagella. In addition, Cfap61-deficient mice showed the OAT phenotype, suggesting that loss of function of CFAP61 was the cause of OAT. Two individuals accepted ICSI therapy using their own ejaculated sperm, and one of them succeeded in fathering a healthy baby.
Conclusions Our findings indicate that CFAP61 is essential for spermatogenesis and that biallelic CFAP61 variants lead to male infertility in humans and mice with OAT.
- reproductive health
- genetic research
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information. Not applicable.
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TH and LM contributed equally.
Correction notice This article has been corrected since it was published Online First. A statement about equal contributorship has been added.
Contributors Y-QT designed the research; TH, LM, CT and CL performed research; W-BH, CT, HN, HZ, JD and GL performed the bioinformatics analysis; JD, GL and G-XL analysed the data; Y-QT, TH and LM analysed the data and wrote the paper; Y-QT is the guarantor of the research.
Funding This work was supported by grants from the National Key Research & Developmental Program of China (2018YFC1004901), the National Natural Science Foundation of China (81771645 and 81971447), the Key Grant of Prevention and Treatment of Birth Defect from Hunan Province (2019SK1012), Hunan Provincial Grant for Innovative Province Construction (2019SK4012) and the Research Grant of CITIC-Xiangya (YNXM-202004, YNXM-202006).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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