Experience of an academic reference laboratory using automation for analysis of cystic fibrosis mutations

Objective. - To examine the use of partial automation for molecular analysis of cystic fibrosis and to evaluate the diagnostic experience gained. Design. - Twenty-four cystic fibrosis mutations, with cumulative mutation detection of 89% in North American whites and of 97% in the Ashkenazim, were tested by multiplex amplification and allele-specific oligonucleotide hybridization. Setting. - A university-based DNA diagnostic laboratory. Subjects. - More than 700 serial specimens were analyzed for cystic fibrosis mutations over a 5-month period. The study included 377 individuals tested for carrier status, of which 288 had no family history for cystic fibrosis; prenatal diagnosis for 17 fetuses at a one in four risk and eight pregnancies at lower risk; fetal or parental samples for 33 pregnancies with fetal ultrasound abnormalities; 40 individuals diagnosed with cystic fibrosis; and 87 individuals with a possible diagnosis of the disease. Results. - Automation has permitted increasing numbers of mutations while decreasing personnel time and cost. Mutation testing identified 10 carriers with no family history for cystic fibrosis, four couples at a one in four risk, and five affected fetuses, one ascertained by abnormal fetal ultrasound. Mutation analysis also identified two mutant copies of the gene in 26 of 40 individuals with a clinical diagnosis of cystic fibrosis, and in two of 87 patients with possible cystic fibrosis. Conclusion. - This partially automated, direct mutation analysis provides DNA diagnostic laboratories with the capacity to process a larger number of samples at lower cost with greater sensitivity for mutation detection. As pilot screening programs are reported, it is appropriate to reevaluate recommendations regarding population-based carrier screening for cystic fibrosis.