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 1800 357-5744
 * 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