[Genetics and male infertility]

Area of Science:

• Reproductive Medicine and Genetics
• Human Genetics
• Spermatogenesis Research

Context:

• Male factor contributes to infertility in approximately 50% of couples experiencing difficulties conceiving.
• Genetic factors are an underlying cause for a subset of male infertility cases.
• Research focuses on identifying genetic mutations and chromosomal abnormalities linked to male reproductive issues.

Purpose:

• To investigate the role of genetic factors, including Y chromosome microdeletions and mutations in X-linked and autosomal genes, in male infertility.
• To analyze deletions on the long arm of the Y chromosome (Yq microdeletions) and their prevalence in infertile men.
• To examine mutations in specific X-linked (NXF2, USP26, TAF7L) and autosomal genes (SYCP3, MSH4, DNMT3L, STRA8, ETV5) associated with spermatogenesis.

Summary:

• Studies on Yq microdeletions found complete AZF deletions in 4.6% of infertile men, often requiring assisted reproductive technologies.
• Investigated X-linked genes (NXF2, USP26, TAF7L) and autosomal genes (SYCP3, MSH4, DNMT3L, STRA8, ETV5); only alterations in STRA8 and ETV5 were absent in normozoospermic controls, but likely not causative.
• Overall, mutations were rarely detected in men with fertility problems, suggesting a low frequency of identifiable genetic causes.

Impact:

• Yq microdeletions, particularly complete AZF deletions, are a confirmed genetic cause of male infertility, though with a low prevalence.
• Current research indicates that mutations in the investigated X-linked and autosomal genes are infrequently associated with male infertility.
• Highlights the need for continued research to fully elucidate the genetic underpinnings of male infertility and identify novel causative factors.