Summarizing the human genes and their variants causative of non-obstructive azoospermia uncovered using whole...

Azoospermia represents 15 % of male infertility cases and is characterized by the total absence of sperm cells in the ejaculate. Recent studies on non-obstructive azoospermia (NOA) underline the significance of genetic diagnosis such as whole-exome sequencing (WES) and whole-genome sequencing (WGS) to identify the genetic causes of the disease. In this review, we aim to pinpoint genes and their variants uncovered to date related to NOA using next-generation sequencing. We also provide a unique functional classification of NOA-related genes. Furthermore, we highlight the importance of consanguineous families for uncovering genes and their variants, a point that is largely missing in other reviews. We included all relevant article types, regardless of their publication period, and excluded the articles related to the AZF region. Gene expression data in human and mouse testes were sourced from the NCBI Gene database. The localization/expression of genes were explored using Human Protein Atlas (single-cell type). 230 genes related to azoospermia were identified, divided and categorized based on their function in spermatogenesis and their expression level in the testis. We also highlighted the gene and its variants uncovered in consanguineous families. This review represents a step closer to the creation of a NOA gene panel essential for the routine diagnosis of infertility and perhaps a future strategy for treatment.