Novel homozygous CFAP69 mutations in humans and mice cause severe asthenoteratospermia with multiple morphological abnormalities of the sperm flagella

2018 ◽  
Vol 56 (2) ◽  
pp. 96-103 ◽  
Author(s):  
Xiaojin He ◽  
Weiyu Li ◽  
Huan Wu ◽  
Mingrong Lv ◽  
Wangjie Liu ◽  
...  

BackgroundMale infertility is a major issue of human reproduction health. Asthenoteratospermia can impair sperm motility and cause male infertility. Asthenoteratospermia with multiple morphological abnormalities of the flagella (MMAF) presents abnormal spermatozoa with absent, bent, coiled, short and/or irregular-calibre flagella. Previous studies on MMAF reported that genetic defects in cilia-related genes (eg, AKAP4, DNAH1, CFAP43, CFAP44 and CFAP69) are the major cause of MMAF. However, the known MMAF-associated genes are only responsible for approximately 30% to 50% of human cases. We further investigated the cases with MMAF in search of additional genes mutated in this condition.Methods and resultsWe conducted whole exome sequencing in a male individual with MMAF from a consanguineous Han Chinese family. Sanger sequencing was also conducted in additional individuals with MMAF. Intriguingly, a homozygous frameshift mutation (p.Leu357Hisfs*11) was identified in the gene encoding CFAP69 (cilia and flagella-associated protein 69), which is highly expressed in testis. The subsequent Sanger sequencing of the CFAP69 coding regions among 34 additional individuals with MMAF revealed a case with homozygous nonsense mutation (p.Trp216*) of CFAP69. Both of these CFAP69 loss-of-function mutations were not present in the human population genome data archived in the 1000 Genomes Project and ExAC databases, nor in 875 individuals of two Han Chinese control populations. Furthermore, we generated the knockout model in mouse orthologue Cfap69 using the CRISPR-Cas9 technology. Remarkably, male Cfap69-knockout mice manifested with MMAF phenotypes.ConclusionOur experimental findings elucidate that homozygous loss-of-function mutations in CFAP69 can lead to asthenoteratospermia with MMAF in humans and mice.

2019 ◽  
Vol 19 (10) ◽  
pp. 758-765
Author(s):  
Yuan Wu ◽  
Yi Guo ◽  
Jinzhong Yuan ◽  
Hongbo Xu ◽  
Yong Chen ◽  
...  

Background: Alport syndrome (AS) is an inherited familial nephropathy, characterized by progressive hematuric nephritis, bilateral sensorineural hypoacusis and ocular abnormalities. X-linked AS (XLAS) is the major AS form and is clinically heterogeneous, and it is associated with defects in the collagen type IV alpha 5 chain gene (COL4A5). Objective: The purpose of this research is to detect the genetic defect responsible for renal disorder in a 3-generation Han-Chinese pedigree. Methods: Detailed family history and clinical data of the family members were collected and recorded. Whole exome sequencing (WES) was applied in the proband to screen potential genetic variants, and then Sanger sequencing was used to verify the variant within the family. Two hundred unrelated ethnically matched normal individuals (male/female: 100/100, age 37.5 ± 5.5 years) without renal disorder were recruited as controls. Results: Three patients (I:1, II:1 and II:2) presented microscopic hematuria and proteinuria, and the patient I:1 developed uremia and end stage renal disease (ESRD) by age 55 and showed sensorineural hearing loss. Patient II:2 developed mild left ear hearing loss. Cataracts were present in patients I:1 and II:1. A COL4A5 gene missense variant, c.2156G>A (p.G719E), located in the Gly-X-Y repeats of exon 28, was identified to co-segregate with the renal disorder in this family. The variant was absent in 200 ethnically matched controls. Conclusion: By conducting WES and Sanger sequencing, a COL4A5 missense variant, c.2156G>A (p.G719E), was identified to co-segregate with the renal disorder, and it is possible that this variant is the genetic cause of the disorder in this family. Our study may extend the mutation spectrum of XLAS and may be useful for genetic counseling of this family. Further functional studies associated with genetic deficiency are warranted in the following research.


2019 ◽  
Vol 57 (2) ◽  
pp. 89-95 ◽  
Author(s):  
Weiyu Li ◽  
Huan Wu ◽  
Fuping Li ◽  
Shixiong Tian ◽  
Zine-Eddine Kherraf ◽  
...  

BackgroundMale infertility is a prevalent issue worldwide, mostly due to the impaired sperm motility. Multiple morphological abnormalities of the sperm flagella (MMAF) present aberrant spermatozoa with absent, short, coiled, bent and irregular-calibre flagella resulting in severely decreased motility. Previous studies reported several MMAF-associated genes accounting for approximately half of MMAF cases.Methods and resultWe conducted genetic analysis using whole-exome sequencing in 88 Han Chinese MMAF probands. CFAP65 homozygous mutations were identified in four unrelated consanguineous families, and CFAP65 compound heterozygous mutations were found in two unrelated cases with MMAF. All these CFAP65 mutations were null, including four frameshift mutations (c.1775delC [p.Pro592Leufs*8], c.3072_3079dup [p.Arg1027Profs*41], c.1946delC [p.Pro649Argfs*5] and c.1580delT [p.Leu527Argfs*31]) and three stop-gain mutations (c.4855C>T [p.Arg1619*], c.5270T>A [p.Leu1757*] and c.5341G>T [p.Glu1781*]). Additionally, two homozygous CFAP65 variants likely affecting splicing were identified in two MMAF-affected men of Tunisian and Iranian ancestries, respectively. These biallelic variants of CFAP65 were verified by Sanger sequencing and were absent or very rare in large data sets aggregating sequence information from various human populations. CFAP65, encoding the cilia and flagella associated protein 65, is highly and preferentially expressed in the testis. Here we also generated a frameshift mutation in mouse orthologue Cfap65 using CRISPR-Cas9 technology. Remarkably, the phenotypes of Cfap65-mutated male mice were consistent with human MMAF.ConclusionsOur experimental observations performed on both human subjects and on Cfap65-mutated mice demonstrate that the presence of biallelic mutations in CFAP65 causes the MMAF phenotype and impairs sperm motility.


Author(s):  
Qi Qiao ◽  
Cui-Mei Zhao ◽  
Chen-Xi Yang ◽  
Jia-Ning Gu ◽  
Yu-Han Guo ◽  
...  

AbstractObjectivesDilated cardiomyopathy (DCM) represents the most frequent form of cardiomyopathy, leading to heart failure, cardiac arrhythmias and death. Accumulating evidence convincingly demonstrates the crucial role of genetic defects in the pathogenesis of DCM, and over 100 culprit genes have been implicated with DCM. However, DCM is of substantial genetic heterogeneity, and the genetic determinants underpinning DCM remain largely elusive.MethodsWhole-exome sequencing and bioinformatical analyses were implemented in a consanguineous Chinese family with DCM. A total of 380 clinically annotated control individuals and 166 more DCM index cases then underwent Sanger sequencing analysis for the identified genetic variation. The functional characteristics of the variant were delineated by utilizing a dual-luciferase assay system.ResultsA heterozygous variation in the MEF2A gene (encoding myocyte enhancer factor 2A, a transcription factor pivotal for embryonic cardiogenesis and postnatal cardiac adaptation), NM_001365204.1: c.718G>T; p. (Gly240*), was identified, and verified by Sanger sequencing to segregate with autosome-dominant DCM in the family with complete penetrance. The nonsense variation was neither detected in 760 control chromosomes nor found in 166 more DCM probands. Functional analyses revealed that the variant lost transactivation on the validated target genes MYH6 and FHL2, both causally linked to DCM. Furthermore, the variation nullified the synergistic activation between MEF2A and GATA4, another key transcription factor involved in DCM.ConclusionsThe findings firstly indicate that MEF2A loss-of-function variation predisposes to DCM in humans, providing novel insight into the molecular mechanisms of DCM and suggesting potential implications for genetic testing and prognostic evaluation of DCM patients.


2019 ◽  
Vol 39 (1) ◽  
Author(s):  
Qin Xiang ◽  
Yanna Cao ◽  
Hongbo Xu ◽  
Yi Guo ◽  
Zhijian Yang ◽  
...  

Abstract Stargardt disease (STGD1, OMIM 248200) is a common hereditary juvenile or early adult onset macular degeneration. It ultimately leads to progressive central vision loss. Here, we sought to identify gene mutations associated with STGD1 in a three-generation Han Chinese pedigree by whole exome sequencing and Sanger sequencing. Two novel potentially pathogenic variants in a compound heterozygous state, c.3607G>T (p.(Gly1203Trp)) and c.6722T>C (p.(Leu2241Pro)), in the ATP binding cassette subfamily A member 4 gene (ABCA4) were identified as contributing to the family’s STGD1 phenotype. These variants may impact the ABCA4 protein structure and reduce the retinal-activated ATPase activity, leading to abnormal all-trans retinal accumulation in photoreceptor outer segments and in retinal pigment epithelium cells. The present study broadens the mutational spectrum of the ABCA4 responsible for STGD1. A combination of whole exome sequencing and Sanger sequencing is likely to be a time-saving and cost-efficient approach to screen pathogenic variants in genetic disorders caused by sizable genes, as well as avoiding misdiagnosis. These results perhaps refine genetic counseling and ABCA4-targetted treatments for families affected by STGD1.


2019 ◽  
Vol 8 (8) ◽  
pp. 405-413
Author(s):  
Jianbo Huang ◽  
Xiaogang Bao ◽  
Wenjun Xia ◽  
Lingjun Zhu ◽  
Jin Zhang ◽  
...  

Objectives X-linked hypophosphataemic rickets (XLHR) is a disease of impaired bone mineralization characterized by hypophosphataemia caused by renal phosphate wasting. The main clinical manifestations of the disorder are O-shaped legs, X-shaped legs, delayed growth, and bone pain. XLHR is the most common inheritable form of rickets, with an incidence of 1/20 000 in humans. It accounts for approximately 80% of familial cases of hypophosphataemia and serves as the prototype of defective tubular phosphate (PO43+) transport, due to extra renal defects resulting in unregulated FGF23 activity. XLHR is caused by loss-of-function mutations in the PHEX gene. The aim of this research was to identify the genetic defect responsible for familial hypophosphataemic rickets in a four-generation Chinese Han pedigree and to analyze the function of this mutation. Methods The genome DNA samples of all members in the pedigree were extracted from whole blood. We sequenced all exons of the PHEX and FGF23 genes, as well as the adjacent splice site sequence with Sanger sequencing. Next, we analyzed the de novo mutation c.1692 del A of the PHEX gene with an online digital service and investigated the mutant PHEX with SWISS-MODEL, immunofluorescence, and protein stability detection. Results Through Sanger sequencing, we found a de novo mutation, c.1692 del A, in exon 16 of the PHEX gene in this pedigree. This mutation can make the PHEX protein become unstable and decay rapidly, which results in familial XLHR. Conclusion We have found a de novo loss-of-function mutation, c.1692 del A, in exon 16 of the PHEX gene that can cause XLHR. Cite this article: J. Huang, X. Bao, W. Xia, L. Zhu, J. Zhang, J. Ma, N. Jiang, J. Yang, Q. Chen, T. Jing, J. Liu, D. Ma, G. Xu. Functional analysis of a de novo mutation c.1692 del A of the PHEX gene in a Chinese family with X-linked hypophosphataemic rickets. Bone Joint Res 2019;8:405–413. DOI: 10.1302/2046-3758.88.BJR-2018-0276.R1.


2021 ◽  
Author(s):  
Xin Zhang ◽  
Jiang Sun ◽  
Yonggang Lu ◽  
Jintao Zhang ◽  
Keisuke Shimada ◽  
...  

Cilia and flagella are ancient structures that achieve controlled motor functions through the coordinated interaction based on microtubules, and some attached projections. Radial spokes (RSs) facilitate the beating motion of these organelles by mediating signal transduction between dyneins and a central pair (CP) of singlet microtubules. RS complex isolation from Chlamydomonas axonemes enabled the detection of 23 radial spoke proteins (RSP1-23), with the roles of some radial spoke proteins remained unknown. Recently, RSP15 has been reported to be located to the stalk of RS2, but its homolog in mammals has not been explored. Herein, we show that Lrrc23 is an evolutionarily conserved testis-enriched gene encoding an RSP15 homolog in mice. We found that LRRC23 localizes to the RS complex within murine sperm flagella and interacts with RSPH3A/B. The knockout of Lrrc23 resulted in male infertility due to RS disorganization and impaired motility in murine spermatozoa, whereas the ciliary beating was unaffected significantly. These data indicate that LRRC23 is a key regulator underpinning the integrity of RS complex within the flagella of mammalian spermatozoa, whereas it is dispensable in cilia.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Shuai Lu ◽  
Yayun Gu ◽  
Yifei Wu ◽  
Shenmin Yang ◽  
Chenmeijie Li ◽  
...  

AbstractInner dynein arm (IDA), composed of a series of protein complex, is necessary to cilia and flagella bend formation and beating. Previous studies indicated that defects of IDA protein complex result in multiple morphological abnormalities of the sperm flagellum (MMAF) and male infertility. However, the genetic causes and molecular mechanisms in the IDAs need further exploration. Here we identified two loss-of-function variants of WDR63 in both MMAF and non-obstructive azoospermia (NOA) affected cohorts. WDR63 encodes an IDA-associated protein that is dominantly expressed in testis. We next generated Wdr63-knockout (Wdr63-KO) mice through the CRISPR-Cas9 technology. Remarkably, Wdr63-KO induced decreased sperm number, abnormal flagellar morphology and male infertility. In addition, transmission electron microscopy assay showed severely disorganized “9 + 2” axoneme and absent inner dynein arms in the spermatozoa from Wdr63-KO male mice. Mechanistically, we found that WDR63 interacted with WDR78 mainly via WD40-repeat domain and is necessary for IDA assembly. Furthermore, WDR63-associated male infertility in human and mice could be overcome by intracytoplasmic sperm injection (ICSI) treatment. In conclusion, the present study demonstrates that bi-allelic variants of WDR63 cause male infertility via abnormal inner dynein arms assembly and flagella formation and can be used as a genetic diagnostic indicator for infertility males.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Ying Shen ◽  
Feng Zhang ◽  
Fuping Li ◽  
Xiaohui Jiang ◽  
Yihong Yang ◽  
...  

2019 ◽  
Vol 56 (10) ◽  
pp. 678-684 ◽  
Author(s):  
Wensheng Liu ◽  
Yanwei Sha ◽  
Yang Li ◽  
Libin Mei ◽  
Shaobin Lin ◽  
...  

BackgroundMultiple morphological abnormalities of the sperm flagella (MMAF) is a kind of severe teratozoospermia. Patients with the MMAF phenotype are infertile and present aberrant spermatozoa with absent, short, coiled, bent and/or irregular flagella. Mutations in several genes can explain approximately 30%–50% of MMAF cases and more genetic pathogenies need to be explored. SPEF2 was previously demonstrated to play an essential role in sperm tail development in mice and pig. Dysfunctional mutations in SPEF2 impair sperm motility and cause a short-tail phenotype in both animal models.ObjectiveBased on 42 patients with severe infertility and MMAF phenotype, we explored the new genetic cause of human MMAF phenotype.Methods and resultsBy screening gene variants in 42 patients with MMAF using whole exome sequencing, we identified the c. 12delC, c. 1745-2A > G, c. 4102 G > T and c. 4323dupA mutations in the SPEF2 gene from two patients. Both of these mutations are rare and potentially deleterious. Transmission electron microscope (TEM) analysis showed a disrupted axonemal structure with mitochondrial sheath defects in the patients’ spermatozoa. The SPEF2 protein level was significantly decreased in the spermatozoa of the patients revealed by Western blot (WB) and immunofluorescence (IF) analyses.ConclusionOur experimental findings indicate that loss-of-function mutations in the SPEF2 gene can cause the MMAF phenotype in human.


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