PDF(Pubmed)
Abstract：
OBJECTIVE: To identify the genetic causes of multiple morphological abnormalities in sperm flagella (MMAF) and male infertility in patients from two unrelated Han Chinese families.
METHODS: Whole-exome sequencing was conducted using blood samples from the two individuals with MMAF and male infertility. Hematoxylin and eosin staining and scanning electron microscopy were performed to evaluate sperm morphology. Ultrastructural and immunostaining analyses of the spermatozoa were performed. The HEK293T cells were used to confirm the pathogenicity of the variants.
RESULTS: We identified two novel homozygous missense ARMC2 variants: c.314C > T: p.P105L and c.2227A > G: p.N743D. Both variants are absent or rare in the human population genome data and are predicted to be deleterious. In vitro experiments indicated that both ARMC2 variants caused a slightly increased protein expression. ARMC2-mutant spermatozoa showed multiple morphological abnormalities (bent, short, coiled, absent, and irregular) in the flagella. In addition, the spermatozoa of the patients revealed a frequent absence of the central pair complex and disrupted axonemal ultrastructure.
CONCLUSIONS: We identified two novel ARMC2 variants that caused male infertility and MMAF in Han Chinese patients. These findings expand the mutational spectrum of ARMC2 and provide insights into the complex causes and pathogenesis of MMAF.
METHODS: Whole-exome sequencing was conducted using blood samples from the two individuals with MMAF and male infertility. Hematoxylin and eosin staining and scanning electron microscopy were performed to evaluate sperm morphology. Ultrastructural and immunostaining analyses of the spermatozoa were performed. The HEK293T cells were used to confirm the pathogenicity of the variants.
RESULTS: We identified two novel homozygous missense ARMC2 variants: c.314C > T: p.P105L and c.2227A > G: p.N743D. Both variants are absent or rare in the human population genome data and are predicted to be deleterious. In vitro experiments indicated that both ARMC2 variants caused a slightly increased protein expression. ARMC2-mutant spermatozoa showed multiple morphological abnormalities (bent, short, coiled, absent, and irregular) in the flagella. In addition, the spermatozoa of the patients revealed a frequent absence of the central pair complex and disrupted axonemal ultrastructure.
CONCLUSIONS: We identified two novel ARMC2 variants that caused male infertility and MMAF in Han Chinese patients. These findings expand the mutational spectrum of ARMC2 and provide insights into the complex causes and pathogenesis of MMAF.
摘要：
目的：确定两个无关的汉族家庭患者精子鞭毛（MMAF）多重形态异常和男性不育的遗传原因。
方法：使用来自两个患有MMAF和男性不育症的个体的血液样本进行全外显子组测序。进行苏木精和伊红染色和扫描电子显微镜以评估精子形态。进行精子的超微结构和免疫染色分析。HEK293T细胞用于确认变体的致病性。
结果：我们鉴定了两个新的纯合错义ARMC2变体：c.314C>T：p.P105L和c.2227A>G：p.N743D。两种变体在人类群体基因组数据中不存在或罕见,并且被预测为有害的。体外实验表明，两种ARMC2变体均导致蛋白质表达略有增加。ARMC2-突变体精子表现出多种形态异常（弯曲，短,盘绕,缺席,和不规则）在鞭毛中。此外,患者的精子经常缺乏中央对复合体，并破坏了轴突超微结构。
结论：我们发现了两种新的ARMC2变异体在中国汉族患者中引起男性不育和MMAF。这些发现扩展了ARMC2的突变谱，并为MMAF的复杂原因和发病机理提供了见解。
方法：使用来自两个患有MMAF和男性不育症的个体的血液样本进行全外显子组测序。进行苏木精和伊红染色和扫描电子显微镜以评估精子形态。进行精子的超微结构和免疫染色分析。HEK293T细胞用于确认变体的致病性。
结果：我们鉴定了两个新的纯合错义ARMC2变体：c.314C>T：p.P105L和c.2227A>G：p.N743D。两种变体在人类群体基因组数据中不存在或罕见,并且被预测为有害的。体外实验表明，两种ARMC2变体均导致蛋白质表达略有增加。ARMC2-突变体精子表现出多种形态异常（弯曲，短,盘绕,缺席,和不规则）在鞭毛中。此外,患者的精子经常缺乏中央对复合体，并破坏了轴突超微结构。
结论：我们发现了两种新的ARMC2变异体在中国汉族患者中引起男性不育和MMAF。这些发现扩展了ARMC2的突变谱，并为MMAF的复杂原因和发病机理提供了见解。
