['The aim of this study was to define the features of chronic cryptogenic hepatitis (CCH) in childhood and to investigate whether it is related to hepatitis G virus infection.', 'Forty-six children (24 males; age range, 1.5 to 17 years) with CCH were studied. CCH was diagnosed when serum alanine aminotransferase concentrations were more than 1.5 times normal for longer than 6 months without any apparent cause of liver disease.', 'No patient had acute symptomatic onset or had received a blood transfusion. Three had undergone minor surgical procedures. All appeared to be healthy during follow-up (median, 4.2 years; range, 1 to 10 years). Hypertransaminasemia was the only aberrant liver function test. Elevated serum alanine aminotransferase values alternated with normal values in 40 children (86.9%). Five children (10.8%) had a spontaneous sustained (>12 months) remission of hypertransaminasemia. Twelve (26%) had laboratory signs of autoimmunity, but none fulfilled the criteria for autoimmune hepatitis. Of 20 children who underwent liver biopsy, 13 (65%) had minimal chronic hepatitis, 4 (20%) had mild chronic hepatitis and 3 (15%) had moderate chronic hepatitis. Serum hepatitis G virus RNA was detected in 2 girls (4%) whose risk factor was a hepatitis G virus-infected mother and a minor surgical procedure, respectively. In 12 families at least 1 other member had chronic liver disease.'] Is chronic cryptogenic hepatitis in childhood unrelated to hepatitis G virus?