Liver function test of the patient showed the mildly and intermittently elevated alanine aminotransferase (ALT) levels ranging from 70 to 92 U/L and aspartate aminotransferase (AST) levels ranging from 80 to 90 U/L, which began at 8 months of age and lasted for 4 years without CF diagnosis. The gene discussed is GPT; the disease is cystic fibrosis.