Biallelic mutations inCFAP65lead to severe asthenoteratospermia due to acrosome hypoplasia and flagellum malformations

Abstract

BackgroundThe genetic causes for most male infertility due to severe asthenozoospermia remain unclear.ObjectiveOur objective was to identify unknown genetic factors in 47 patients with severe asthenozoospermia from 45 unrelated Chinese families.MethodsWe performed whole exome sequencing of 47 individuals with severe asthenozoospermia from 45 unrelated families. Mutation screening was performed in a control cohort of 637 individuals, including 219 with oligoasthenospermia, 195 with non-obstructive azoospermia and 223 fertile controls. Ultrastructural and immunostaining analyses of patients’ spermatozoa were performed to characterise the effect of variants.ResultsOne homozygous non-sense mutation (NM_194302, c.G5341T:p.E1781X), two compound heterozygous mutations (c.C2284T:p.R762X and c.1751delC:p.P584fs) and two compound heterozygous mutations (c.5714_5721del:p.L1905fs and c.C3021A:p.N1007K) were identified in CFAP65 of three individuals with completely immotile spermatozoa, respectively. No biallelic deleterious variants of CFAP65 were detected in the control cohort of 637 individuals. Ultrastructural and immunostaining analyses of spermatozoa from two patients showed highly aberrant sperm morphology with severe defects such as acrosome hypoplasia, disruption of the mitochondrial sheath and absence of the central pair complex.ConclusionTo the best of our knowledge, we are the first to report that CFAP65 mutations may cause spermatozoa to be completely immotile.

Novel homozygous truncating variants in ZMYND15 causing severe oligozoospermia and their implications for male infertility

“…A total of 414 idiopathic male individuals with primary infertility, including 219 patients with SO and 195 patients with azoospermia, were recruited between June 2014 and December 2018 in the reproductive and genetic hospital of CITIC-Xiangya, as previously described (Tu et al, 2020;W. Wang et al, 2019).…”

“…Written informed consent was obtained from each participant. A total of 414 idiopathic male individuals with primary infertility, including 219 patients with SO and 195 patients with azoospermia, were recruited between June 2014 and December 2018 in the reproductive and genetic hospital of CITIC‐Xiangya, as previously described (Tu et al, 2020; W. Wang et al, 2019). The patients were recruited following the guidelines of the WHO laboratory manual for the examination and processing of human semen (Sanchez‐Alvarez et al, 2012).…”

An M1AP homozygous splice‐site mutation associated with severe oligozoospermia in a consanguineous family

“…Other infertility causes, such as hormonal levels and developmental effects, were excluded. We performed targeted look‐up for M1AP variants in 243 subjects with SO and 223 subjects with normal fertility, described in our previous study . Subsequently, genomic DNA samples were subjected to WES as previously described, followed by Sanger sequencing.…”

The Male Is Significantly Implicated as the Cause of Unexplained Infertility

“…79 In a recent screen of 90 asthenozoospermic patients, mutations in the dynein intermediate and heavy chain genes (DNAI1, DNAH5, and DNAH11) were found in 7.8% of cases. 79 Other genetic causes of severe asthenozoospermia include mutations in AK7 (adenylate kinase 7) 80 ; CCDC103 (coiled-coil domain containing 103) 81 ; DNAJB13 (DnaJ heat-shock protein family [Hsp40] member B13) 82 ; QRICH2 (glutamine rich 2) 83 ; CFAP43, CFAP44, CFAP65, CFAP69, and CFAP70 (cilia-and flagella-associated proteins 43 and 44, 65, 69, 70) [84][85][86] ; CEP135 (centrosomal protein 135) 87 ; FSIP2 (fibrous sheath interacting protein 2) 88 ; DZIP1 (DAZ interacting zinc finger protein 1) 89 ; and SPEF2 (sperm flagellar 2). 63 Not all of the genes associated with asthenozoospermia concern the flagellum itself, some studies have also suggested that deletions within the mitochondrial genome may also generate this phenotype 90 -which is unexpected given the human spermatozoon's heavy reliance on glycolysis rather than oxidative phosphorylation.…”