Molecular analysis of northwestern Mexican patients with cystic fibrosis: screening of 10 known mutations. Mutations in brief no. 185. Online.

We have analyzed 45 unrelated Northwestern Mexican patients with Cystic Fibrosis for 10 known CF mutations (DF508, G542X, G551D. R553X, W1282X, NI303K, R334W, R347H, S549R, and R1162X). Screening was performed on exons 7, 10, 11, 19, 20 and 21 using standard methods such as polymerase chain reactions, reverse dot blot hybridization (non-radioactive), and restriction enzyme digestion. The analysis for these ten mutations permitted the identification of only two mutations in 37.7% of CF chromosomes in this sample. The major mutation, delta F508, accounts for 34.4% of CF chromosomes. Of the 45 CF patients 9 (20.0%) were homozygous delta F508 deletion, 11 (24.4%) were heterozygous for the delta F508 mutation and an unknown mutation. One additional mutation G542X was also found in 3 chromosomes in our population (3.3%). Two patients were documented to be a compound heterozygote for DF508/G542X, and other one heterozygous for G542X and an unknown mutation. Therefore 62.2% of chromosomes remain uncharacterized.