"disease_ontology"^^ . . _:vb50939826 . _:vb50939826 . . _:vb50939826 . . "spermatogenic failure 21"^^ . _:vb50939826 . . "DOID:0070163"^^ . "OMIM:617644"^^ . _:vb50939826 . "A male infertility due to acephalic spermatozoa that is characterized by acephalic spermatozoa, reduced sperm number and impaired sperm motility that has_material_basis_in homozygous mutation in the BRDT gene on chromosome 1p22."^^ .