Genetic etiological spectrum of sperm morphological abnormalities

Area of Science:

• Genetics
• Reproductive Biology
• Human Physiology

Background:

• Male infertility affects sperm count, motility, and fertilizing ability.
• Sperm structural defects, or teratozoospermia, often stem from genetic mutations.
• Understanding these genetic bases is crucial for diagnosing and treating male infertility.

Purpose of the Study:

• To comprehensively review and analyze genetic mutations causing sperm morphological deformities (teratozoospermia).
• To classify genes based on the specific sperm defects they induce.
• To consolidate current knowledge on the genetic underpinnings of teratozoospermia.

Main Methods:

• Conducted a literature review to identify genes associated with sperm morphological abnormalities.
• Classified identified genes according to the type of sperm defect caused (e.g., acephalic, globozoospermia, MMAF).
• Assessed the level of evidence for each gene based on human studies and mouse knockout data.

Main Results:

• Identified specific genes linked to various head defects, including SUN5, DPY19L2, AURKC, WDR12, RNF220, AMZ2, CC2D1B, SEPT14, SEPT12, and others.
• Cataloged genes responsible for multiple morphological abnormalities of sperm flagella (MMAF), such as DNAH1, DNAH2, DNAH6, and CFAP43.
• Reported mutations in 31 genes causing sperm head defects and 62 genes causing sperm tail defects.

Conclusions:

• Genetic mutations are a significant cause of teratozoospermia, affecting sperm morphology.
• A substantial number of genes (31 for head defects, 62 for tail defects) have been implicated in sperm structural abnormalities.
• Further research into these genes can advance the diagnosis and potential treatment of male infertility.