Cystic Fibrosis Flashcards
Gene product responsible
CFTR gene
Cystic fibrosis transmembrane conductance regulator gene
Major morbidity and mortality is attributable to
Respiratory compromise
- copius hyperviscous abd adherent pulmonary secrtions
Complete name of the disease
Cystic fibrosis of the pancreas
Most common genetic abnormalities
F508del mutation
CFTR mutations that disrupts protein maturarion - class II
Class III abnormalities
G551D (glycine to aspartic acid replacement at CFTR postion 551)
Inability to transport Cl and HCO3 in the presence of ATP
Class I
G542X
R553X
W1282X
Premature termination codon replaces glycine, arginine, tryptophan at posistions 542, 553 1282
Prevalent among Ashkenezi decsent
Predominant CF genotypy in Israel
W1282X mutation
Class IV
Class V
Class VI
Defects in ion channel PORE
RNA splicing
Increase plasma membrane turnover
Class VI
Increased plasma membrane turnover
Diagnostic test used in newborn screening
High levels of immunoreactive trypsinogen
Mainstay diagnosis prior to the availability of CFTR genotyping
Sweat test - highly specific
—elevated chloride
Class of defect with a reduced number of CFTR transcripts due to a promoter or splicing abnormality
Class V
Both CFTR genotyping and sweat test inconclusive, what test is used?
In vivo measurement of ion transport across the nasal airways
“Severe” defects that impair CFTR activity predictive of pancreatic insufficiency
- F508del
- G551D
- Truncation alleles
Forme frustes of cystic fibrosis - assoc with with CFTR mutation in at least one allele
- Isolated congenital bilateral absence of vas deferens
2. Pancreatitis (without other organ system findings)
