GTF2A1L (general transcription factor IIA subunit 1 like) functions as a testis-specific transcription factor involved in male fertility and reproductive development. The protein binds DNA in conjunction with GTF2A2 and TBP (TATA-binding protein), enabling mRNA transcription by RNA polymerase II 1. GTF2A1L expression is regulated by tissue-specific DNA methylation patterns, with aberrant methylation of its promoter region associated with hypospermatogenesis in males with non-obstructive azoospermia 2. However, while altered GTF2A1L expression correlates with testicular dysfunction, it does not appear to affect fertilization rates in testicular sperm extraction procedures 2. Single nucleotide polymorphisms in GTF2A1L are associated with FSH levels in azoospermic patients, suggesting a role in hormonal regulation of spermatogenesis 1. Additionally, the gene has been implicated in neurodevelopmental disorders, with altered expression observed in neural progenitors from fragile X syndrome patients 3. GTF2A1L variants have also been identified in genome-wide association studies of age-related macular degeneration bilaterality and polycystic ovary syndrome, indicating broader roles in disease susceptibility beyond male fertility 45.