DDX3Y

DDX3Y is a human gene located on the Y chromosome that encodes an RNA helicase of the DEAD-box family. It is the Y-chromosome paralog of DDX3X, which resides on the X chromosome. As a member of the DEAD-box helicase family, DDX3Y is expected to participate in remodeling RNA structures and ribonucleoprotein complexes, contributing to processes such as translation initiation, RNA metabolism, and ribosome biogenesis. Its protein product shares conserved motifs with DDX3X, suggesting overlapping biochemical activities, though functional emphasis may differ between paralogs.

Expression of DDX3Y is strongest in male reproductive tissues, particularly the testis, aligning with a proposed role in spermatogenesis. The precise RNA targets and cellular functions of DDX3Y in humans are not fully defined, and research continues to delineate its specific substrates and interactions.

Clinical relevance for DDX3Y arises mainly in the context of male fertility. Disruptions of DDX3Y, including deletions or copy-number variations on the Y chromosome, have been associated with infertility phenotypes such as azoospermia or severe oligozoospermia in some individuals. In diagnostic settings for male infertility, DDX3Y is considered alongside other Y-linked fertility genes, though infertility is typically multifactorial and the contribution of DDX3Y can vary.

Evolutionarily, DDX3Y represents an X–Y gene pair that arose as a duplicate of DDX3X and is part of broader patterns of Y-linked genes implicated in reproductive biology. In somatic tissues, the role of DDX3Y is less clearly defined than that of DDX3X, and functional overlap between the paralogs remains an area of investigation.