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

To examine the use of partial automation for molecular analysis of cystic fibrosis and to evaluate the diagnostic experience gained.

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.

A university-based DNA diagnostic laboratory.

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.

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.

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.