Phenotypic variability in five cystic fibrosis patients compound heterozygous for the Y1092X mutation

Five cystic fibrosis (CF) patients distributed in three families and compound heterozygotes for the Y1092X mutation have been followed for a period ranging from 5 to 20 years. The genealogical reconstruction identified a common ancestor couple to all 3 families at the 5th generation. All 5 patients were pancreatic insufficient. A high variability in the clinical aspects and pulmonary function was seen between the families, but not within. Based on our observations, it will be very difficult to predict the course of disease for CF patients with the Y1092X mutation, even if they are closely related (first-degree cousins).