Next generation sequencing based exploration of potential candidate variants and microRNAs in patients with idiopathic Hypospermatogenesis sub-type of Non-Obstructive Azoozpermia

Abstract

Hypospermatogenesis (HS) is among the most prevalent histopathological subtype of primary testicular failure and is characterized by a decrease in the total number of germ cells within the seminiferous tubules, leading to azoospermia or oligospermia. Spermatozoa retrieval for intracytoplasmic sperm injection in hypospermatogenesis cases has a high success rate, but there is a risk that the progeny will inherit genomic and epigenetic causative factors. A multifactorial etiology is associated with all subtypes of primary testicular failure, and a broad multiomics approach is required to identify and classify them. Due to the rare nature of the condition, a total of 30 HS patients were recruited and based on availability of blood and testicular tissue samples whole exome sequencing and miRNA sequencing was performed. In-silico analysis and prediction tools were used for target and pathway prediction. Exome sequencing revealed copy number variants in the TLK1 and MTOR genes and single nucleotide variants in the CDC27 and TUBB8 genes. Small RNA sequencing and nCounter miRNA expression analysis showed differential miRNA expression profile of 240 downregulated and 186 upregulated miRNAs in HS patients. The in-silico prediction using the miRNA profile showed evidence for cellular proliferation and differentiation pathways as important targets.