Screening for cystic fibrosis mutations in southern France: identification of a frameshift mutation and two missense variations.

In the search for mutations in the cystic fibrosis gene in patients from the Mediterranean area, we have analysed exons 4, 9, 10, 19, and 21 by the single-strand conformation polymorphism (SSCP) technique in 50 patients with at least one non-delta F508 chromosome. Ten samples demonstrated a shifted band, four in exon 19 and six in exon 21. Sequencing of the PCR fragments has led to the identification of three new sequence alterations, two in exon 19 (3737 delA and I1234V), and one in exon 21 (N1303H). We also analysed the frequency of two known intronic polymorphisms in front of exon 19 (C to A change at nucleotide 3601-65) and exon 21 (G to A change at position 4006-200).