Cystic fibrosis in Japan

A nation wide survey for cystic fibrosis was carried out in Japan from 1982 to 1989. Cystic fibrosis was determined by extended criteria including high concentration of sweat chloride (more than 60 mEq/L), digestive, and respiratory manifestations, and family history. A total of 25 cases were confirmed as cystic fibrosis during the survey. Patients' characteristics were; age ranged from 0 day to 20 years old at diagnosis, sex ratio was 11:14 (M:F). All cases had respiratory, digestive symptoms and abnormally high sweat chloride excretion. Five cases from 3 families showed familiar involvement. These results show that cystic fibrosis is rare but really exists among Japanese. Further investigation including gene analysis should be carried out.