What is Cystic Fibrosis DNA Testing?
Cystic fibrosis is inherited in an autosomal recessive pattern. This means that two mutated copies of the CFTR gene must be present before an individual experiences any symptoms of cystic fibrosis. If an individual has one normal, fully functional CFTR gene and one that carries a mutation, they are known as a carrier and will not experience any disease symptoms. However, they can still pass a copy of the mutated gene to the next generation.
The cystic fibrosis DNA test offered here identifies 39 common disease-causing mutations in the CFTR gene. This testing is useful for not only confirming a cystic fibrosis diagnosis, but also for identifying cystic fibrosis carriers. If two carriers have a child, there is a 25% chance that their child will suffer from cystic fibrosis.
What is the CFTR Gene?
The CFTR gene encodes the cystic fibrosis transmembrane conductance regulator. This regulator is important for controlling the salt levels in the body. When mutations occur in the CFTR gene, an excess of thick sticky mucus accumulates in the respiratory and digestive systems.
None. This test can be taken at any age.
Buccal swabs. The test kit contains buccal swabs and instructions for collecting a buccal swab sample from inside the mouth.
Four buccal swabs, rubbed inside the mouth against the cheek for 15 seconds.
1 – 2 weeks.
Genetic mutations in the CFTR gene
Laboratory specimens are analyzed to detect the presence of 39 CFTR mutations. Analytical specificity and sensitivity for detection of these alleles are >99%. Other mutations not listed are not detected.
DNA test kits do not have an expiry date and can be used at any time. Once the DNA sample is collected, it must be returned to the laboratory for testing within three months of collection. No refrigeration is required. Store at room temperature.
Limitations of the Test
The 39 mutations in this panel account for the majority of cystic fibrosis cases worldwide, particularly in Ashkenazi Jewish populations and Northern European Caucasians. However, other disease-causing mutations are possible, and will not be detected in this DNA analysis.
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