DNAH1 and Azoospermia: DNAH6 can act both recessively and possibly through trans-heterozygous interactions with other PCD genes such as DNAH1 or DNAH5. Dynein is involved in spermatogenesis, and other patients with a rare homozygous missense mutation in DNAH6 exhibited azoospermia and oligozoospermia and male infertility (21, 34).