The Y chromosome is one of the two sex chromosomes in humans — the other being the X chromosome — present exclusively in biological males (XY), who inherit it from their father. It is the smallest human chromosome and carries a limited number of protein-coding genes, most of which are involved in male sex determination and spermatogenesis, including the SRY gene (Sex-determining Region Y), which triggers testicular development during embryogenesis. Although the Y chromosome plays a less prominent role than the X chromosome in gene therapy indications, it is relevant in the context of cell and gene therapy manufacturing for sex-based biological characterization of starting materials, donor screening in allogeneic therapies, and genomic identity testing of cell lines and cell banks used in GMP production.
