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, respectively. 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 1800 variants 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.E60*, p.R75*, p.G85E, c.262_263delTT, c.273+3A>C, c.274-1G>A, c.313delA, p.R117C, p.R117H, p.Y122*, c.489+1G>T, p.G178R, c.579+1G>T, p.L206W, c.803delA, p.F312del, c.948delT, p.G330*, p.R334W, p.R347P, p.R347H, p.R352Q, p.S364P, p.A455E, p.G480C, p.Q493*, p.I507del, p.F508del, p.V520F, c.1545_1546delTA, c.1585-1G>A, p.G542*, p.S549N, p.S549R/c.1647T>G , p.G551D, p.R553*, p.A559T, p.R560T, c.1680-1G>A, c.1766+1G>A, c.1766+5G>T, c.2051_2052delAAinsG, c.2052delA, c.2175_2176insA, p.G622D, c.1923_1931del9insA, c.2012delT, p.K710*, c.2657+5G>A, p.Q890*, c.2737_2738insG, c.2988G>A, c.2988+1G>A, c.3067_3072delATAGTG, p.R1066C, p.W1089*, p.Y1092*, p.M1101K, p.D1152H, p.R1162*, c.3528delC, p.R1158*, c.3659delC, p.S1196*, c.3717+12191C>T, c.3773_3774insT, p.W1282*, p.D1270N, p.S1255*, c.3744delA, p.N1303K.


Ethnic GroupCarrier Frequency    Detection RateCarrier Risk
Ashkenazi Jewish 1 in 24 94% 1 in 400
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


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. releases /nr12-12-01-2.cfm
4. TAG-It Mutation Detection Kit for CFTR 70+6 package insert, Tm Bioscience Corporation, Toronto, Ontario

Specimen Requirements:

Post-natal: Two 5-10 mL tubes of anticoagulated blood in EDTA (lavendar top) or two 5-10mL tubes of anticoagulated blood in ACD (yellow top). 


  • Chorionic Villi: 5-10 mg in conical tube with sterile saline OR transport media
  • Amniotic Fluid: 10 ml in conical tube
  • Cultured Cells: two confluent T-25 flasks

Additionally, please send:

  • 5-10 ml maternal blood in EDTA (lavender top) required to perform MCC studies on all prenatal samples and in case maternal confirmation studies are necessary
  • 5-10 paternal blood in EDTA (lavender top) in case paternal confirmation studies are necessary

Shipping: Send at room temperature.

Turnaround Time: 10-14 days

CPT Code: 81220

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

Additional Information: Expanded Ashkenazi Jewish Carrier Screening brochure [PDF] and Carrier Screening Brochure [PDF]

Related Tests: Ashkenazi Jewish Carrier Screening Panel