Background: A genotype/phenotype correlation between early onset cystic fibrosis related diabetes (CFRD) and the N1303K mutation of the CF gene was previously identified in a small series of 28 CFRD patients, out of 313 CF patients.
Patients and methods: In order to confirm the observation, data of 141 CFRD patients out of 1,229 CF patients attending 14 Italian CF centers were collected. All patients were older than 10 years and had been genotyped.
Results: DeltaF508 was the most frequent mutation (147/282 alleles: 52%) and N1303K the second most frequent mutation (18/282 alleles: 6.3%) in CFRD patients, without significant difference as compared with CF patients without DM (52% vs 48.6% and 6.3% vs 5.1%, respectively). W1282X was the third most frequent mutation in CFRD patients, more frequent than in CF patients without DM (5.3% vs 2%; p<0.001).
Conclusions: Unlike the previous study, we did not find a higher frequency of the N1303K mutation in CFRD patients; moreover, data from this large CF series showed a significant correlation between the W1282X mutation and CFRD.