Cystic Fibrosis

CYSTIC FIBROSIS

Gene Symbol: CFTR

Chromosomal Locus: 7q31.2

Protein: cystic fibrosis transmembrane conductance regulator

Pseudonyms: CF, cystic fibrosis transmembrane conductance regulator, ATP-binding cassette sub-family C, member 7, Congenital Absence of the Vas Deferens (CAVD)

TURNAROUND TIME: 8 days

2012 AMA Code: 81220

TESTING METHODOLOGY: This assay uses xTAG ® Nucleic Acid Assay Technology Combined with PCR and Allele Specific Primer Extension (ASPE) to detect 60 mutations/variants that includes ACMG 23 mutations and 37 North American most common mutations; including 4 normal variants.

SPECIMEN REQUIREMENTS:

Collect: Prefer two 5ml whole blood EDTA (lavender top) tube.
Min. Collection: 0.7 ml whole blood EDTA.
Transport: blood EDTA at Room Temp shipped regular next day air (No Saturday delivery; store specimen at 4°C and ship Monday).
Stability: Ambient: up to 7 days; Refrigerated: 2 weeks. Frozen: unacceptable
Unacceptable Conditions: Serum. Frozen or severely hemolyzed blood. Clotted blood.
Prenatal testing: Direct: 5ml direct unspun amniotic fluid or 15mg CVS tissue with a backup flask growing. Culture: confluent T25 flask. Maternal blood sample is required for maternal cell contamination studies.

A Molecular Genetics Laboratory Test Requisition must accompany the specimen. Contact the Molecular Laboratory at 918-502-1721 to obtain further information.

Note: Counseling and informed consent are recommended for genetic testing. A consent form is available as a resource but not required.

INTERPRETATIVE DATA:

Incidence: 1 in 3,500 in the US and Northern European Caucasian populations are affected with Cystic Fibrosis. 1 in 20 of this same population are carriers of a Cystic Fibrosis mutation. Significant differences occur in other ethnic populations.

Inheritance: Autosomal recessive. However, a single mutation may lead to Congenital Absence of the Vas Deferens (CAVD) in some cases.

Disease Characteristics: Classical cystic fibrosis affects salt regulation in epithelia which affects secretory organs. Pulmonary disease resulting in lower airway inflammation and chronic endobronchial infection, progressing to end-stage lung disease is the most dramatic symptom. However, meconium ileums can occur at birth and pancreatic insufficiency leads to food malabsorption. Also more than 95% of males with CF are infertile. A milder form of CF, CAVD results in azoospermia and infertility but none of the more severe symptoms.

Molecular Genetic Mechanism: More than 1000 point mutations and small deletions are known to occur throughout the gene.

Clinical Sensitivity: The panel identifies >90% of the mutations in the US and Northern European Caucasian populations. Significant differences in detection rates occur in other ethnic populations.

Analytical Sensitivity: 99%

Test Limitations: This test only detects the 60 mutations and 4 normal variants that are in the panel. Rare diagnostic errors can occur due to primer / probe site mutations or rare polymorphisms.

INDICATIONS FOR USE: