PCSK9 and congenital bilateral aplasia of vas deferens from CFTR mutation: Indeed, Langsted et al. [24] have shown, in 103,083 individuals from the Copenhagen General Population Study, that patients with loss-of-function mutation of PCSK9 (PCSK9 R46L) are associated with decreased serum LDL and Lp(a) levels and a reduced risk of calcific aortic stenosis (CAVD).