Those three heterozygotes for the Finnish founder mutation for CLD, c.949_951delGTG (p.Val318del) (Table 1), had severe OAT and, in one of the subjects, azoospermia to which an additional contributor may be the heterozygosity of the CFTR 5 T allele. The gene discussed is CFTR; the disease is congenital secretory chloride diarrhea 1.