Cystic Fibrosis

Test Description:
Cystic fibrosis (CF) is one of the most common autosomal recessive disorders affecting Caucasians with a carrier frequency among Ashkenazi Jewish and non-Jewish Caucasian individuals of 1 in 25 to 1 in 29. Clinical manifestations in affected individuals result from defects in the cystic fibrosis transmembrane regulatory (CFTR) gene and cause the abnormal regulation of chloride channels and the generalized dysfunction of exocrine glands leading to chronic pulmonary disease and pancreatic insufficiency. To date over 1000 mutations have been identified, however common mutations occur in greater frequency in different populations. Among the Ashkenazi Jewish community, five mutations [p.F508del, p.W1282X, p.G542X, p.N1303K, c.3717+12191C>T(3849+10kbC>T)] provide a carrier detection rate of approximately 94%. The American College of Obstetricians and Gynecologists and the American College of Medical Genetics recommend that carrier screening for a core panel of 23 CFTR mutations be offered to all individuals before/during pregnancy. However, cystic fibrosis testing at Mount Sinai tests DNA samples for 70 CFTR mutations which are listed below.

CFTR: p.E60X, p.R75X, p.G85E, c.262_263delTT(394delTT), c.273+3A>C(405+3A>C), c.274-1G>A(406-1G>A), c.313delA(444delA), p.R117C, p.R117H, p.Y122X, c.489+1G>T(621+1G>T), p.G178R, c.579+1G>T(711+1G>T), p.L206W, c.803delA(935delA), p.F312del(delF311), c.948delT(1078delT), p.G330X, p.R334W, p.R347P, p.R347H, p.R352Q, p.S364P, p.A455E, p.G480C, p.Q493X, p.I507del, p.F508del, p.V520F, c.1545_1546delTA(1677delTA), c.1585-1G>A(1717-1G>A), p.G542X, p.S549N, p.S549R/c.1647T>G (S549R), p.G551D, p.R553X, p.A559T, p.R560T, c.1680-1G>A(1812-1G>A), c.1766+1G>A(1898+1G>A), c.1766+5G>T(1898+5G>T), c.2051_2052delAAinsG(2183AA>G), c.2052delA(2184delA), c.2175_2176insA(2307insA), p.G622D, c.1923_1931del9insA(2055del9>A), c.2012delT(2143delT), p.K710X, c.2657+5G>A(2789+5G>A), p.Q890X, c.2737_2738insG(2869insG), c.2988G>A(3120G>A), c.2988+1G>A(3120+1G>A), c.3067_3072delATAGTG(3199del6), p.R1066C, p.W1089X, p.Y1092X, p.M1101K, p.D1152H, p.R1162X, c.3528delC(3659delC), p.R1158X, c.3659delC(3791delC), p.S1196X, c.3717+12191C>T(3849+10kbC>T), c.3773_3774insT(3905insT), p.W1282X, p.D1270N, p.S1255X, c.3744delA(3876delA), p.N1303K).

 

Ethnic Group Carrier Frequency Detection Rate Carrier Risk after Negative Result
Ashkenazi Jewish 1 in 24 94% 1 in 400
Non-Hispanic Caucasian 1 in 25 91% 1 in 268
Hispanic 1 in 58 81% 1 in 301
African American 1 in 61 77% 1 in 266
Asian American 1 in 94 54% 1 in 203

References:
1. Grody WW, Cutting GR, Klinger KW, Richards CS, Watson MS, Desnick RJ; (Subcommittee on Cystic Fibrosis Screening, Accreditation of Genetic Services Committee, ACMG. American College of Medical Genetics). Laboratory standards and guidelines for population-based cystic fibrosis carrier screening. Gen Med. 2001; 3:149-54
2. www.acog.org/from_home/publications/press releases /nr12-12-01-2.cfm
3. www.genet.sickkids.on.ca/cftr
4. TAG-It Mutation Detection Kit for CFTR 70+6 package insert, Tm Bioscience Corporation, Toronto, Ontario

Specimen Requirements:
Two 5-10 ml tubes of anticoagulated blood. The preferred anticoagulant is EDTA (lavendar top tubes), ACD (yellow top) tubes are also accepted.

Shipping: Send at room temperature.

Turnaround Time: 10-14 days

CPT Codes: 83891, 83892x2, 83900, 83901x2, 83912, 83914x2

Consent and Requisition Forms: Carrier Screening Requisition and Consent [PDF]

Additional Information:
Jewish Genetic Screening Brochure [PDF]
General Carrier Screening Brochure [PDF]

Related Tests: Ashkenazi Jewish Carrier Test Panel

Prior to ordering prenatal testing, please contact our laboratory at 212-241-7518 to discuss.