Ali Imtiaz, Yang Meng-Lei, Rahim Fazal, Ali Haider, Zeb Aurang, Ahmad Nisar, Raza Yousaf, Yue Wang, Shoaib Muhammad, Abbas Tanveer, Shah Wasim, Ma Hui, Zhang Huan, Yin Hao, Shi Qing-Hua
Centre for Reproduction and Genetics, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Biomedical Sciences and Health Laboratory of Anhui Province, Institute of Health and Medicine, Hefei Comprehensive National Science Centre, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
Department of Molecular Biology, Massachusetts General Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02114, USA.
Asian J Androl. 2025 Jun 3. doi: 10.4103/aja202538.
The syndrome of multiple morphological abnormalities of the sperm flagella (MMAF) is one of the most serious kinds of sperm defects, leading to asthenoteratozoospermia and male infertility. In this study, we use whole-exome sequencing to identify genetic factors that account for male infertility in a patient born from a consanguineous Pakistani couple. A homozygous frameshift mutation (c.1399_1402del; p.Gln468ArgfsTer2) in axonemal dynein light chain domain containing 1 (AXDND1) was identified in the patient. Sanger sequencing data showed that the mutation was cosegregated recessively with male infertility in this family. Papanicolaou staining and scanning electron microscopy analysis of the sperm revealed severely abnormal flagellar morphology in the patient. Immunofluorescence and western blot showed undetectable AXDND1 expression in the sperm of the patient. Transmission electron microscopy analysis showed disorganized sperm axonemal structure in the patient, particularly missing the central pair of microtubules. Immunofluorescence staining showed the absence of sperm-associated antigen 6 (SPAG6) and dynein axonemal light intermediate chain 1 (DNALI1) signals in the sperm flagella of the patient. These findings indicate that AXDND1 is essential for the organization of flagellar axoneme and provide direct evidence that AXDND1 is a MMAF gene in humans, thus expanding the phenotypic spectrum of AXDND1 frameshift mutations.
精子鞭毛多重形态异常综合征（MMAF）是最严重的精子缺陷类型之一，可导致弱畸精子症和男性不育。在本研究中，我们使用全外显子组测序来鉴定导致一名出生于巴基斯坦近亲结婚夫妇的患者出现男性不育的遗传因素。在该患者中鉴定出轴丝动力蛋白轻链结构域包含1（AXDND1）的纯合移码突变（c.1399_1402del；p.Gln468ArgfsTer2）。桑格测序数据表明，该突变在这个家族中与男性不育呈隐性共分离。对该患者精子进行巴氏染色和扫描电子显微镜分析，发现其鞭毛形态严重异常。免疫荧光和蛋白质印迹显示，该患者精子中未检测到AXDND1表达。透射电子显微镜分析显示，该患者精子轴丝结构紊乱，特别是缺少中央微管对。免疫荧光染色显示，该患者精子鞭毛中不存在精子相关抗原6（SPAG6）和动力蛋白轴丝轻中间链1（DNALI1）信号。这些发现表明，AXDND1对鞭毛轴丝的组织至关重要，并提供了直接证据证明AXDND1是人类中的一个MMAF基因，从而扩展了AXDND1移码突变的表型谱。
