1989; Riordan et al. 1989; Rommens et al. 1989). Although one mutation (deltaF508) accounts for about 70% of CF alleles worldwide (Bobadilla et al. 2002), diverse heritages are reflected for the CFTR gene and distributed with varying frequencies among populations often complicating genetic analysis (Estivill et al. 1997). The current guidelines of the American College of Medical Genetics and Genomics (ACMG) recommend a panel of only 23 variants for population-based CF carrier screening (Watson et al. 2004), leaving the vast majority of possible genotype changes untested. The gene discussed is CFTR; the disease is cystic fibrosis.