Phenotypic heterogeneity in CF sibs compound heterozygous for the G85E and 621 + 1G→T mutations

Short Communication: Little phenotypic variability in three CF sibs compound heterozygous for the 621 + 1G ← T and the 711 + 1G ← T mutations

“…Little phenotypic variation was observed in this family, in contrast to another family in which two sibs who were compound heterozygous for the 621 + 1G-T and G85E mutations had major phenotypic differences (De Braekeleer et al 1995). The earlier colonization by all three bacteria in the later-born sibs suggests that their pulmonary disabling condition predisposed them to be more easily infected by the bacteria first present in their oldest sister.…”

“…Studies on genotype-phenotype correlation in CF patients carrying the 621 + 1G+T mutation have shown that it is associated with pancreatic insufficiency (The Cystic Fibrosis Genotype-Phenotype Consortium 1993, De Braekeleer et al 1995. Based on the assumption that two "severe" alleles causing pancreatic insufficiency are necessary for pancreatic insufficiency to be manifest (Kerem et al 1989, Kristidis et al 1992, we conclude that the 71 1 + l G + T mutation appears to be a "severe" allele causing pancreatic insufficiency.…”

“…Data collected on each patient were extracted from the files kept at the C F clinic where the patients come on a regular basis as outpatients for follow-up and treatment. Details on data gathering can be found in previously published reports (The Cystic Fibrosis Genotype-Phenotype Consortium 1993, De Braekeleer et al 1995.…”