Purpose

Acephalic spermatozoa syndrome (ASS) is known as a severe type of teratozoospermia, defined as semen composed of mostly headless spermatozoa that affect male fertility. In this regard, this systematic review aimed to discuss gene variants associated with acephalic spermatozoa phenotype as well as the clinical outcomes of intracytoplasmic sperm injection (ICSI) treatment for the acephalic spermatozoa-associated male infertility.

Methods

A systematic search was performed on PubMed, Embase, Scopus, and Ovid databases until May 17, 2020. This systematic scoping review was reported in terms of the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) statement.

Results

Twenty articles were included in this systematic review. Whole-exome and Sanger sequencing have helped in the identification of variants in SUN5, PMFBP1, BRDT, TSGA10, DNAH6, HOOK1, and CEP112 genes as possible causes of this phenotype in humans. The results of the ICSI are conflicting due to both positive and negative reports of ICSI outcomes.

Conclusion

ASS has a genetic origin, and several genetic alterations related to the pathogenesis of this anomaly have been recently identified. Notably, only SUN5 and PMFBP1 mutations are well-known to be implicated in ASS. Accordingly, more functional studies are needed to confirm the pathogenicity of other variants. ICSI could provide a promising treatment for acephalic spermatozoa-associated male infertility. Besides the importance of sperm head-tail junction integrity, some other factors, whether within the sperm cell or female factors, may be involved in the ICSI outcome.

中文翻译：

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头侧精子综合征的遗传基础和不育男性胞浆内精子注射结果：系统范围审查

目的

无头精子综合征 (ASS) 被称为严重畸形精子症，定义为精液主要由无头精子组成，影响男性生育能力。在这方面，本系统评价旨在讨论与头侧精子表型相关的基因变异，以及胞浆内精子注射 (ICSI) 治疗头侧精子相关男性不育症的临床结果。

方法

对 PubMed、Embase、Scopus 和 Ovid 数据库进行了系统搜索，直至 2020 年 5 月 17 日。该系统性范围界定审查是根据系统性审查的首选报告项目和范围界定审查的元分析扩展 (PRISMA-ScR) 报告的陈述。

结果

该系统评价包括 20 篇文章。全外显子组和 Sanger 测序有助于鉴定SUN5、PMFBP1、BRDT、TSGA10、DNAH6、HOOK1和CEP112基因中的变异，这些变异可能是人类出现这种表型的原因。由于对 ICSI 结果的正面和负面报道，ICSI 的结果是相互矛盾的。

结论

ASS 有遗传起源，最近发现了一些与这种异常发病机制相关的遗传改变。值得注意的是，众所周知，只有SUN5和PMFBP1突变与 ASS 有关。因此，需要更多的功能研究来确认其他变体的致病性。ICSI 可以为头侧精子相关的男性不育症提供有希望的治疗方法。除了精子头尾连接完整性的重要性外，其他一些因素，无论是在精子细胞内还是女性因素，都可能与 ICSI 结果有关。