Q: What does it mean if a person carries the 5T allele?

A: If a person carries the 5T allele, there may be a slight increase in pancreatitis and sinusitis. The 5T allele is a mutated cystic fibrosis gene.

It is seen in about 10% of people. It's not completely clear what it means if a person is found to carry this gene. In infertile men and in men with a condition called CBAVD (congenital bilateral absence of the vas deferens) researchers have found an increased incidence of the 5T allele.