• cystic fibrosis transmembrane conductance regulator (CFTR)
• mutations
• polymorphism
• chronic pancreatitis

• CBAVD, congenital bilateral absence of the vas deferens
• CF, cystic fibrosis
• CFTR, cystic fibrosis transmembrane conductance regulator

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP regulated Cl⁻ channel that is expressed in many epithelial tissues.¹ In the pancreas CFTR plays a key role in the apical HCO₃^– transport in duct cells.^2–5 Loss of its function due to mutations in the CFTR gene causes cystic fibrosis (CF) of the pancreas with exocrine insufficiency, chronic airway disease, and abnormally elevated sweat chloride concentration. Over 1000 mutations and 200 polymorphic loci in CFTR have now been identified.⁶ These mutations and polymorphisms confer quite variable phenotypes from classic CF to atypical CF with less severe pulmonary lesions, pancreatic sufficiency, and normal or borderline sweat chloride concentration.^7,8 It is now well recognised that the spectrum of CFTR related disease is much broader than previously thought.⁹ Some individuals may exhibit an apparently single clinical feature or a monosymptomatic disease, such as chronic sinusitis, congenital bilateral absence of the vas deferens (CBAVD), and sweat chloride abnormalities. Recent evidence^10–12 suggests that chronic pancreatitis, in at least a subset of the patients, belongs to this group of disease.¹³

Chronic pancreatitis is a progressive inflammatory disease of the pancreas that causes the loss of pancreatic acinar cells, ductal abnormalities often with intraductal stones, and irregular fibrosis. Alcohol is the most common cause of chronic pancreatitis in men but idiopathic pancreatitis is more common in women. The incidence of chronic pancreatitis in Western countries (about 4 per 100 000 population) is similar to that (5.4−5.9 per 100 000) in Japan.¹⁴ However, the incidence of CF in Japanese is very low (1 per 350 000) compared with whites (1 per 2500 live births).^7,15 The apparent large difference of the incidence of CF and chronic pancreatitis may not support the presence of …