ABSTRACT
Two adult sisters affected by cystic fibrosis were both shown to carry two different alterations within exon 11 of the CFTR gene, the nonsense mutation G542X and the missense mutation G551D. Both patients exhibit a relatively benign clinical course. In the described patients, G542X functions as a "mild" allele and is, in this respect, dominant to the "severe" G551D.
Subject(s)
Cystic Fibrosis/genetics , Exons/genetics , Membrane Proteins/genetics , Adult , Cystic Fibrosis Transmembrane Conductance Regulator , Female , Genotype , Humans , Phenotype , Sequence AnalysisABSTRACT
A total of 56 Duchenne muscular dystrophy (DMD) patients and 11 Becker muscular dystrophy (BMD) patients was analyzed by extended "multiplex" amplification of the DMD/BMD gene; deletions were found in 60% of these patients. The data obtained were used to test the frameshift hypothesis and to compare the distribution of familial versus isolated cases. A significant correlation was found between deletions and isolated cases. Additional experiments were performed in order to determine the deletion breakpoints more precisely. These data are a prerequisite for carrier analysis in the respective families by detection or exclusion of aberrant cDNA fragments derived from ectopic lymphocyte RNA. This diagnostic technique is illustrated by 5 examples.
