ABCMdb

PMID: 1284888

Hamosh A, Rosenstein BJ, Cutting GR
CFTR nonsense mutations G542X and W1282X associated with severe reduction of CFTR mRNA in nasal epithelial cells.
Hum Mol Genet. 1992 Oct;1(7):542-4., [PubMed]

Sentences

No. Mutations Sentence Comment

1 ABCC7 p.Trp1282* ABCC7 p.Gly542* 1, No. 7 542-544 CFTR nonsense mutations G542X and W1282X associated with severe reduction of CFTR mRNA in nasal epithelial cells Ada Hamosh12 *, Beryl J.Rosenstein2 and Garry R.Cutting1 '2 -3 1 Center for Medical Genetics, departments of Pediatrics and 3 Medicine, the Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA Received July 8, 1992; Revised and Accepted August 28, 1992 Cystic fibrosis (CF) is caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene (1). Login to comment 3 ABCC7 p.Arg553* We have reported that the R553X mutation (2) is associated with severe reduction of CFTR mRNA in respiratory epithelial cells of CF patients (3), and that this reduction is associated with undetectable CFTR protein (4). Login to comment 4 ABCC7 p.Trp1282* ABCC7 p.Gly542* The nonsense mutations G542X and W1282X (5) are also among the most common CFTR mutations (CF Genetic Analysis Consortium). Login to comment 5 ABCC7 p.Trp1282* Furthermore, W1282X is the most common CFTR mutation in the Ashkenazi Jewish population, where it is present on 60% of CF chromosomes (6). Login to comment 6 ABCC7 p.Trp1282* ABCC7 p.Trp1282* ABCC7 p.Trp1282* ABCC7 p.Gly542* ABCC7 p.Gly542* To study the effect of these nonsense mutations upon mRNA processing, nasal epithelial cells were obtained from two carriers of the G542X mutation, three compound heterozygotes for G542X and AF5O8, two carriers of the W1282X mutation, one homozygote for the W1282X mutation and one W1282X/AF5O8 nasal polyp cell culture. Login to comment 17 ABCC7 p.Trp1282* The ASOs are as indicated; the dots are in duplicate. The W1282X/AF508 cDNA is derived from a nasal polyp cell culture; the AF508/unknown cDNA is derived from a tracheal cell culture. Login to comment 28 ABCC7 p.Gly542* For the G542X mutation, cDNA was amplified using CFTR primers Exon 7-5' and Exon 11-3' (3). Login to comment 32 ABCC7 p.Gly542* Figure la shows the results of ASO hybridization to amplified genomic DNA and cDNA from one compound heterozygote for the G542X mutation. Login to comment 33 ABCC7 p.Trp1282* For the W1282X mutation, cDNA was amplified using Exon 18-5' and Exon 24-3' (3); genomic DNA was amplified using 20i-5 and 2CH-3 (5). Login to comment 35 ABCC7 p.Trp1282* Figure lb shows the ASO hybridization results from one homozygote and two heterozygotes for the W1282X mutation. Login to comment 42 ABCC7 p.Trp1282* ABCC7 p.Trp1282* ABCC7 p.Gly542* ABCC7 p.Gly542* Quantitation by densitometry (The Discovery Series™ Scanner, PDI, Huntingdon Station, NY) demonstrated that the level of transcripts derived from the G542X nonsense mutation was consistently less than 10% of the normal or AF5O8 allele, while that of the W1282X mutation was consistently less than 5% of the normal or AF508 allele. In this study, we demonstrate that the CFTR nonsense mutations G542X and W1282X are associated with severely reduced levels of CFTR mRNA in nasal epithelial cells. Login to comment 43 ABCC7 p.Gly542* Decreased levels of mRNA carrying the G542X mutation have been observed in both respiratory and rectal epithelia (10). Login to comment 44 ABCC7 p.Trp1282* ABCC7 p.Gly542* These findings suggest that the G542X and W1282X mutations should result in severely decreased or undetectable CFTR protein and add to the growing evidence that nonsense mutations usually result in reduced transcript levels, as has been observed in many human disease genes (11, 12). Login to comment 46 ABCC7 p.Trp1282* ABCC7 p.Trp1282* Comparison of CF patients homozygous for the W1282X mutation with patients who are compound heterozygotes for the W1282X and AF5O8 mutations revealed that both groups were severely affected (6). Login to comment 47 ABCC7 p.Gly542* No large scale analysis of patients carrying the G542X mutation has been reported. Login to comment 49 ABCC7 p.Trp1282* ABCC7 p.Arg553* ABCC7 p.Gly542* Approximately 3% of CF patients will be homozygous or compound heterozygous for the G542X, R553X, and W1282X mutations. Login to comment 107 ABCC7 p.Gly542* Joanna Rommens for the sample of CFTR plasmid DNA, Dr Arthur Beaudet for genomic DNA from a G542X homozygote, Dr Bat-Sheva Kerem for the 542X and 542NL ASOs, and Dr Iain Mclntosh for advice. Login to comment