Cystic Fibrosis

Question 1

Cystic fibrosis gene

Answer 1

CFTR

Question 2

CF symptoms

Answer 2

Salty tasting skin, perpetual cough, frequent lung infections, wheezing, shortness of breath, difficulty gaining weight, bowel problems, progressive pulmonary disease, pulmonary infection, pancreatic insufficiency, intestinal malabsorption, liver disease, pancreatitis, male infertility

Question 3

CF life expectancy

Answer 3

37 years

Question 4

CF Caucasian incidence

Answer 4

1/3,300

Question 5

Clinical effects of CFTR R117H mutation

Answer 5

R117H with 5T - carrier or mildly affected (cis - classic CF mutation; trans - may have CBAVD). R117H with 7T/9T - carrier (cis - mild CF mutation)

Question 6

Clinical effects of CFTR F508C mutation

Answer 6

Non CF causing variant that can result in CBAVD when paired with CF causing mutation

Question 7

Clinical effects of CFTR I506V/I507V variants

Answer 7

Not associated with CF/CBAVD. Compound hets of dF508 or dF508 with I506V or I507V can appear as homozygotes on some assays (labeling carriers as affecteds)

Question 8

NBS strategy for CF diagnosis

Answer 8

Heel stick –> DNA testing –> sweat chloride test