Handbook of Genetic Counseling/Cystic Fibrosis Carrier Screening-1

Cystic Fibrosis Carrier Screening

Disease Characteristics

• Autosomal recessive (use visual aide to describe)
• Build up of mucus in lungs and pancreas
• Failure to thrive
• Diarrhea
• Pneumonia
• Small intestine obstruction
• Pulmonary disease
• Pancreatic disease
• Male infertility
• Survival rate= aprox. average of 35 years
• Cognitive function is typically not impaired

Incidence rates

• 1/3300 live births - Caucasian
• 1/15300 - African American
• 1/32000- Asian

Carrier frequencies

• 1/26 in the Ashkenazi Jewish Population
• 1/25 N. and S. European
• 1/46 Hispanic
• 1/60 African American
• 1/90 Asian American

Who should be tested

• Individuals with a family history and their partners
• Couples planning pregnancy from the high risk ethnic backgrounds
• Gamete donors
• Spouses of a known carrier
• NIH recommended in April 1999 that all pregnant couples get offered this test and all planning pregnancies

Types of testing

• DNA - PCR using DF508 and 7 other mutations (use visual aide to describe)
  • Done by a multiple of centers
  • $235.00
  • Turnaround time is 7-10 days
  • Carrier test detection rate
    • 80-90% (depends on center)
  • Blood sample
    • 10-15cc
    • lavender EDTA
• DNA chip - 86 mutations
  • Done by Genzyme (1-800-848-4436): http://www.genzymegenetics.com/Our-Services/Reproductive-Testing/cf-plus.aspx
  • 7-14 days turnaround
  • $235.00
  • Carrier Test Detection Rates
    • 90% for N. Europeans
    • 70% for S. Europeans
    • 97% for Ashkenazi Jewish
    • 75% for African American
  • Blood samples
    • 20cc for adults
    • 5-7cc for children
    • yellow-top ACD-A
    • lavender top EDTA
• Linkage - extremely rare mutations in a family

Notes

The information in this outline was last updated in 2002.