GGTLC1 and liver disorder: The diagnosis of liver disease was considered if at least one of the following was present in two consecutive evaluations in a period of 6 months: hepatomegaly (liver edge palpable more than 2 cm below the costal margin on the mid clavicular line); elevation of alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT) > 1.5 the normal value; ultrasound abnormalities consistent with liver involvement according to conventional criteria.