_:vb50946429 . _:vb50946429 . _:vb50946429 "A spermatogenic failure characterized by infertility resulting from absence of oocyte activation and ultrastructural abnormalities of the sperm head that has_material_basis_in homozygous or compound heterozygous mutation in ACTL9 on chromosome 19p13.2."^^ . _:vb50946429 . _:vb50946429 . _:vb50946429 . _:vb50946429 "url:https://pubmed.ncbi.nlm.nih.gov/33626338/"^^ .