About 10% of male infertile patients show abnormalities in spermatogenesis. The microdeletion of azoospermia factor a (AZFa) region of the Y chromosome is thought to be a cause of spermatogenic failure. However. candidate gene responsible for the spermatogenic failure in AZFa deleted patients has not been elucidated yet. https://www.chiggate.com/color-charm-050-cooling-violet-supply/