USP9Y and Sertoli Cell-Only Syndrome: Although deletions occurring in AZFa are mostly associated with Sertoli cell only syndrome [23], severe oligozoospermia in our patient with AZFa and AZFc deletions was not surprising because Kamp et al. [23] also reported that only complete AZFa deletion is associated with the absence of sperm whereas there have been cases of sperm retrieval with partial AZFa deletions.