has part has part has_part characteristic of has modifier abnormal vas deferens morphology absent vas deferens agenesis of vas deferens MP:0003557 vas deferens aplasia MPheno.ontology MP:0003556 absent ductus deferens ductus deferens aplasia absence of the secretory duct of the testicle that carries spermatozoa, running from the epididymis, of which it is the continuation, to the prostatic urethra where it terminates to form ejaculatory duct abnormal absent vas deferens