Linkage Disequilibrium between Cystic Fibrosis Mutations and Polymorphic 4-bp Repeat within CFTR Gene

Abstract

The PCR technique was used in a study of the linkage of cystic fibrosis mutations and a polymorphic (GATT)_n repeat in intron 6 of the CFTR gene. Absolute linkage disequilibrium was found between the common ΔF-508 mutation and the (GATT)₆ allele. This allele was also in linkage disequilibrium with other unidentified mutations in the CFTR gene resulting in the pancreatic insufficient form of disease. The frequency of (GATT)_n alleles in the pancreatic sufficient form of CF did not differ significantly from the data obtained in the total population. The significance of the (GATT)_n polymorphic repeat for the diagnosis of CF is discussed.