Re: vas deferens
You must have a misunderstanding. The vas deferens is simply a tube that carries sperm from the testes; it is not a disorder. However there can be disorders of the vas deferens such an absence of the tube that can cause infertility. If only one of the tubes is missing, the person can still have normal sperm movement. if both tubes are missing, it is not possible for the sperm to travel the necessary path. There are probably other disorders of the vas deferens.