No association between the Delta F508 cystic fibrosis mutation and type 2 diabetes mellitus

cystic fibrosis (CF) is one of the most common recessively inherited disord ers in Caucasian populations and is caused by mutations in the CF transmemb rane conductance regulator (CFTR) gene. A three base deletion known as Delt a F508 occurs on about 70% of CF chromosomes and accounts for the high prev alence of the disease. Since type 2 diabetes mellitus occurs more frequentl y in relatives of patients with CF than in the normal population, we addres sed the hypothesis whether heterozygosity; for Delta F508 might be a geneti c risk factor for type 2 diabetes. We screened 301 patients with type 3 dia betes mellitus which had been treated for at least three years from diagnos is by diet or oral antihyperglycemic agents. Healthy controls (n = 282) had no family history for diabetes. The genotype distribution did not differ s ignificantly between patients with type 2 diabetes (2% heterozygotes) and c ontrols (3% heterozygotes). According to these results, we conclude, that t he Delta F508 mutation in its heterozygous form does not represent a major genetic risk factor for type 2 diabetes mellitus.