SUN5复合杂合突变导致无头精子症一例

doi:10.12280/gjszjk.20260048

摘要/Abstract

摘要：

无头精子症是一种严重的精子畸形，指精液中含有无头精子尾和一些松散的精子头部，主要表现为头颈部连接异常。报告1例因无头精子症就诊的男性不育患者，经家系全外显子组测序以及Sanger测序验证，发现该患者SUN5基因存在c.7C>T(p.Arg3Trp)和c.1043A>T(p.Asn348Ile)复合杂合突变，其父母是该突变位点的杂合携带者。进一步蛋白质功能分析显示SUN5复合杂合突变对SUN5蛋白功能具有破坏性，提示该患者可能是由于SUN5基因突变导致的无头精子症。患者的配偶通过卵胞质内单精子注射（intracytoplasmic sperm injection，ICSI）技术获得临床妊娠并活产，提示对于此类患者，ICSI是目前最直接的辅助生殖手段。

关键词: 无头精子症, 不育，男（雄）性, 突变, 遗传变异, 精子注射，细胞质内

Abstract:

Acephalic spermatozoa is a severe sperm malformation characterized by the presence of sperm without heads and detached sperm heads, and abnormal head-neck connections in the semen. Here we report a case of male infertility due to acephalic spermatozoa. Through family-based whole exome sequencing and Sanger sequencing verification, it was found that the patient has compound heterozygous mutations c.7C>T(p.Arg3Trp) and c.1043A>T(p.Asn348Ile) in the SUN5 gene. Both parents were the heterozygous carriers of these mutations. Further protein functional assays predicted that the compound heterozygous mutations in SUN5 are disruptive to protein function. These findings suggest that SUN5 mutation may be a causative factor for acephalic spermatozoa in this patient. The spouse of the patient achieved clinical pregnancy and live birth through intracytoplasmic sperm injection (ICSI) technology, indicating that ICSI is currently the most direct assisted reproductive method for such patients.

Key words: Acephalic spermatozoa, Infertility, male, Mutation, Genetic variation, Sperm injections, intracytoplasmic

陈海霞, 杨琳, 穆晓环, 宋学茹, 田文艳, 白晓红. SUN5复合杂合突变导致无头精子症一例[J]. 国际生殖健康/计划生育杂志, 2026, 45(4): 285-289.

CHEN Hai-xia, YANG Lin, MU Xiao-huan, SONG Xue-ru, TIAN Wen-yan, BAI Xiao-hong. Compound Heterozygous Mutations in SUN5 Cause Acephalic Spermatozoa: A Case Report[J]. Journal of International Reproductive Health/Family Planning, 2026, 45(4): 285-289.

图/表 4

图1 精子形态图注：A~D 显微镜下精子形态（×40）；E~H 改良巴氏染色后精子形态（×100）。

图2 患者及其父母Sanger测序结果及家系图注：A c.7C>T和c.1043A>T突变区域的Sanger测序图谱；B 家系图。

表1 全外显子组测序结果

基因	染色体位置	核酸改变	氨基酸改变	转录本	外显子/内含子	杂合性	人群频率	疾病及遗传模式	致病性
SUN5	chr20:g.31571697T>A	c.1043A>T	p.Asn348Ile	NM_080675.4	EXON 13	杂合	0.000 9	16型生殖功能障碍常染色体隐性遗传	临床意义未明
SUN5	chr20:g.31592140G>A	c.7C>T	p.Arg3Trp	NM_080675.4	EXON 1	杂合	0	16型生殖功能障碍常染色体隐性遗传	临床意义未明

图3 SUN5蛋白结构和功能分析注：A SUN5基因c.7C>T(p.Arg3Trp)和c.1043A>T(p.Asn348Ile)复合杂合突变对蛋白功能的影响；B 突变位点对蛋白结构的影响。

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