PDHA2 encodes the E1-alpha subunit of the pyruvate dehydrogenase (PDH) complex, a heterotetrameric enzyme that catalyzes the conversion of pyruvate to acetyl-CoA and CO2, linking glycolysis and the mitochondrial TCA cycle 1. The E1 subunit performs thiamine pyrophosphate-dependent decarboxylation of pyruvate and reductive acetylation of lipoyl groups on the E2 subunit 2. Unlike its X-linked somatic paralogue PDHA1, PDHA2 is exclusively expressed in testicular germ cells, regulated by demethylation of a CpG island within its coding region 34. PDHA2 is essential for spermatogenesis, functioning in mitochondrial ATP production required for meiotic double-strand break repair through RAD51 and DMC1 ATPase activity 5. Loss-of-function mutations cause non-obstructive azoospermia (NOA) with meiotic arrest 67, and PDHA2 variants have been identified in consanguineous families with combined digit malformation and male infertility 8. Clinical relevance includes NOA diagnosis and potential therapeutic approaches involving PDHA2 mRNA delivery via lipid nanoparticles, which successfully restored spermatogenesis in knockout mice 7.