Deleterious variants in X-linked CFAP47 induce asthenoteratozoospermia and primary male infertility
Deleterious variants in X-linked CFAP47 induce asthenoteratozoospermia and primary male infertility
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X连锁CFAP47的有害变异会诱发弱精子症和原发性男性不育症。
DOI：
10.1016/j.ajhg.2021.01.002
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发表时间：
2021-02-04
影响因子：
9.8
通讯作者：
Zhang, Feng
中科院分区：
文献类型：
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作者：
Liu, Chunyu;Tu, Chaofeng;Zhang, Feng
以多发鞭毛形态异常为特征的弱精子症(MMAF)被认为是男性不育的一个亚型。最近的进展已经在人类受影响的个体中发现了几个与MMAF相关的基因具有常染色体隐性遗传，但大约40%的受影响个体的病因仍然未知。在这里，我们进行了全外显子测序(WES)，并在三名无血缘关系的MMAF中国人中发现了X连锁CFAP47的半合子错义变异。这三个CFAP47变异在人类对照人群基因组数据库中缺失，并通过多种生物信息学工具预测是有害的。CFAP47编码一种纤毛和鞭毛相关蛋白，在睾丸中高表达。免疫印迹和免疫荧光分析显示，携带有害的CFAP47错义变体的三名男性的精子中CFAP47的水平都明显降低。此外，来自澳大利亚的另外一组严重虚弱-畸形精子症男性的WES数据允许鉴定出Xp21.1半合子缺失，移除了整个CFAP47基因。所有携带半合子CFAP47变异的男性都表现出典型的MMAF表型。我们还建立了Cfap47突变的小鼠模型，成年雄性不育，表现为精子活力降低，鞭毛形态和运动异常。然而，通过使用胞浆内单精子注射(ICSI)可以挽救生育能力。总之，我们在人类和小鼠身上的实验观察表明，CFAP47的半合子突变可以诱导X连锁的MMAF和弱畸形精子症，这提示ICSI预后良好。这些发现将为遗传咨询和辅助生殖治疗提供重要的指导。
Asthenoteratozoospermia characterized by multiple morphological abnormalities of the flagella (MMAF) has been identified as a sub-type of male infertility. Recent progress has identified several MMAF-associated genes with an autosomal recessive inheritance in human affected individuals, but the etiology in approximately 40% of affected individuals remains unknown. Here, we conducted whole-exome sequencing (WES) and identified hemizygous missense variants in the X-linked CFAP47 in three unrelated Chinese individuals with MMAF. These three CFAP47 variants were absent in human control population genome databases and were predicted to be deleterious by multiple bioinformatic tools. CFAP47 encodes a cilia- and flagella-associated protein that is highly expressed in testis. Immunoblotting and immunofluorescence assays revealed obviously reduced levels of CFAP47 in spermatozoa from all three men harboring deleterious missense variants of CFAP47. Furthermore, WES data from an additional cohort of severe asthenoteratozoospermic men originating from Australia permitted the identification of a hemizygous Xp21.1 deletion removing the entire CFAP47 gene. All men harboring hemizygous CFAP47 variants displayed typical MMAF phenotypes. We also generated a Cfap47-mutated mouse model, the adult males of which were sterile and presented with reduced sperm motility and abnormal flagellar morphology and movement. However, fertility could be rescued by the use of intra-cytoplasmic sperm injections (ICSIs). Altogether, our experimental observations in humans and mice demonstrate that hemizygous mutations in CFAP47 can induce X-linked MMAF and asthenoteratozoospermia, for which good ICSI prognosis is suggested. These findings will provide important guidance for genetic counseling and assisted reproduction treatments.