Letter: Cystic fibrosis and absence of vas deferens.

Infertility and abnormalities of the mesonephric derivatives are common in patients with 
cystic fibrosis, but it is not a uniform finding. Taussig et 
al. reported on 2 patients with cystic fibrosis who had proved 
fertility. Abnormalities of the vas could be documented in pathologic studies, 
but the vas was found to be present in some patients 
who died of cystic fibrosis. In many patients, absence could not 
be ruled out on physical examination. In healthy, young children the 
vas is not easily palpable; even when it is, the degree 
of certainty in its identification is less than in the post-pubertal 
male. Cystic fibrosis is a disease with protean manifestations, and it 
would be a mistake to rule out cystic fibrosis just because 
the vas can be palpated or to have victims of cystic 
fibrosis labeled as infertile. 