Cystic Fibrosis testing among Arab-Americans.

PURPOSE: Limited data regarding the cystic fibrosis carrier frequency and mutation detection rate is available for Arab-Americans. We retrospectively determined the frequency of carriers among Arab-Americans undergoing preconception and prenatal carrier screening in our laboratories.

METHODS: Between October, 2001 and June, 2005, we performed carrier screening on 805 Arab-Americans, testing for at least the original 25 mutations recommended by the American College of Medical Genetics. We compared our results to previously published studies among Arabic cystic fibrosis patients. We also performed diagnostic testing on seven individuals.

RESULTS: Seven carriers were identified, with an observed carrier frequency of 1 in 115. The most common mutation we identified was W1282X (57% of the mutations detected), followed by DeltaF508 and R117H. Three of 7 patients with a known or suspected diagnosis had two identifiable mutations, including 1548delG, DeltaF508, W1282X, 2789 + 5G>A and R170H.

CONCLUSION: The current recommended carrier screening panel includes only six mutations reported among Arabic cystic fibrosis patients, accounting for 37.1% of the mutations identified among this group. The addition of 1548delG, I1234V, H139L and 4010del4 as part of an extended screening panel would increase the detection rate to 66.3%, similar to the mutation detection rates in other races/ethnic groups.