Increased risk of idiopathic chronic pancreatitis in cystic fibrosis carriers.
Cystic fibrosis (CF) is a recessive disease caused by mutations of the CF transmembrane conductance regulator (CFTR) gene. The risk of idiopathic chronic pancreatitis (ICP) is increased in individuals who have CFTR genotypes containing a CF-causing mutation plus a second pathogenic allele. It is unknown whether the risk of ICP is increased in CF carriers who have one CF-causing mutation plus one normal allele. In this study, 52 sporadic cases of ICP were ascertained through the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer. Individuals with pathogenic cationic trypsinogen mutations were excluded. DNA was comprehensively tested for CFTR mutations using a robotically enhanced, multiplexed, and highly redundant form of single-strand conformation polymorphism (SSCP) analysis followed by DNA sequencing. Fifteen subjects had a total of 18 pathogenic CFTR alleles. Eight subjects had common CF-causing mutations. This group included seven CF carriers in whom the second CFTR allele was normal (4.3 times the expected frequency, P=0.0002). Three subjects had compound heterozygotes genotypes containing two pathogenic alleles (31 times the expected frequency, P<0.0001). A variant allele of uncertain significance (p.R75Q) was detected in eight of the 52 ICP subjects and at a similar frequency (13/96) in random donors. ICP differs from other established CFTR-related conditions in that ICP risk is increased in CF carriers who have one documented normal CFTR allele. Having two CFTR mutations imparts a higher relative risk, while having only one mutation imparts a higher attributable risk.
Cohn
Jonathan A
JA
Department of Medicine, Durham Veterans Administration and Duke University Medical Center, Durham, North Carolina 27710, USA. Cohn0001@mc.duke.edu
Neoptolemos
John P
JP
Feng
Jinong
J
Yan
Jin
J
Jiang
Zefei
Z
Greenhalf
William
W
McFaul
Christopher
C
Mountford
Roger
R
Sommer
Steve S
SS
D000328:Adult; D003550:Cystic Fibrosis / Q000235:genetics* / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006579:Heterozygote; D006801:Humans; D008297:Male; D009154:Mutation / Q000235:genetics / Q000502:physiology*; D050500:Pancreatitis, Chronic; D012307:Risk Factors