Partial deletions of the genes chromo domain Y (CDY) and deleted in azoospermia (DAZ) in the AZFc region lead to reduced sperm count and motility and then showed severe oligozoospermia or even azoospermia.24 Sperm maturation defect and meiosis aberrations occurring in the seminiferous ducts cause a small amount of mature sperm. Here, DAZ1 is linked to Azoospermia.