Hello, If the doctors have examined him and said that it is nothing to worry very likely he has the so-called Gilbert Syndrome. This is a mild condition that is due to reduced liver mechanisms to metabolize due to low glucoronidation (a process many chemicals in the body are broken) and these patients may have increased liver enzymes (generally mild, as is happening with your grandson) and sometimes mild jaundice. It is a benign condition, does not need further investigation and does not affect the health of the child. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Antoneta Zotaj, General & Family Physician