For the D F508 mutation only test, the region of the CF gene containing this mutation is amplified by polymerase chain reaction. Then, analysis of the PCR amplicon by fluorescent hybridization probes will determine a normal genotype, heterozygosity, or homozygosity for D F508 based on the temperature that the probe melts from the product. Specificity may be compromised by PCR primer site mutations. Testing is also beneficial for determining CF carrier status in individuals with a known family history of CF and for prenatal diagnosis of at-risk pregnancies. Individuals with one identified mutation are at least carriers, but may be affected if they also carry one of over 800 reported CF mutations not tested by this assay.
Risk calculations are dependent on race and family history.
The DNA test panel examines the 31 CF mutations, including 24 of the most common CF mutations. Alternatively, testing for the D F508 mutation alone is available. If there is a positive family history of CF, please provide information regarding the relationship of the proband to the individual being tested. Due to the unique nature of genetic susceptibility testing, patients should receive genetic counseling and give informed consent before DNA testing. Informed consent forms are available from ARUP upon request.