男性不孕病人中的先天無輸精管部分和西方常見的遺傳疾病纖維囊腫(Cystic Fibrosis)有關，由一種特殊的基因CFTR突變所造成。CFTR基因突變會造成肺支氣小管、胰腺小管分泌增加並阻塞，引發的綠膿桿菌感染是這些病人夭折的原因。為什麼同樣CFTR基因突變在男性輸精管引起的變化是缺損？我們回顧以往的研究，發現台灣先天無輸精管病人的CFTR基因突變和西方不同，有種族的差異；CFTR基因突變程度和輸精管缺損的嚴重性不相關，而這證據也顯示，CFTR基因突變並非唯一造成先天輸精管缺損的機轉。最近我們用磁核共振掃瞄這些病人的貯精囊和腹內輸精管，更發現輸精管缺損病人的內生殖管道有不同程度的缺損，這和目前的動物實驗結果吻合，CFTR基因突變在輸精管道的早期表現應該也是分泌液增加引發發炎反應，而後在成人期形成不同程度的缺損。其他基因病變的介入，包括引起胚胎期Müllerin管發育不全的基因，也是共同造成先天輸精管缺損的機轉。

In the patients of congenital bilateral absence of vas deferens (CBAVD), part of them is caused by CFTR gene mutation, and related to the cystic fibrosis (CF). The CFTR gene mutation affected the mucosa of bronchial and pancreatic duct, which induced oversecretion of the mucosa and then obstructed the duct. Patients of CF are usually died at their young age with the bronchial and pancreatic duct obstruction which superimposed with Pseudomonas infection. Why the CFTR mutation only affected the male vas deferens (VD) (genital duct) with an unique pathological picture of segmental absence or agenesis?In our previous study, we found the CFTR mutation of Taiwanese CBAVD patients is different from that of caucassian CBAVD, with ethnic difference. However, the severity of the CFTR mutation is not totally related to the absence of the VD. It is one of the evidence the CFTR mutation is not the only mechanism for the pathogenesis of CAVD. Recently, we use the magnetic resonance imaging (MRI) to detect the seminal vesicle (SV) and intra-abdominal VD for the patients of CAVD. Based on our results, patients with CAVD may have a variable lose of the abdominal portion of the VD and seminal vesicle. A similar broad spectrum of SV abnormalities in CBAVD patients was also reported in an autopsy study of CF patients. Another report showed normal genital tract in CF neonates and in CF infants in the first month of life. In the animal study, the absence or dysfunction of CFTR may have resulted in a VD of mutant adult CFTR mice with a differentiated epithelium but a collapsed lumen. This mechanism is very similar to pancreatic duct or bronchial duct obstruction of patients with CF, however, differs from the mechanism of