_:vb50945759 "A spermatogenic failure characterized by nonobstructive azoospermia or oligozoospermia, immotile sperm, and sperm acrosome and head-neck junction abnormalities that has_material_basis_in homozygous or compound geterozygous mutation in SPINK2 on chromosome 4q12."^^ . _:vb50945759 . _:vb50945759 . _:vb50945759 "url:https://pubmed.ncbi.nlm.nih.gov/28554943/"^^ . _:vb50945759 . _:vb50945759 . _:vb50945759 .