A large proportion of patients with recorded liver diagnoses did not have abnormal LFTs, and this highlights the limitation of transaminase testing as a screening tool for liver disease.24 Even patients with ALT 20–40 iU/ml are at increased risk of liver-related mortality and this is independent of the liver diagnosis.25 Furthermore, other key abnormalities in liver biochemistry were not recorded — gamma-glutamyltransferase or alkaline phosphatase — which may be elevated in the context of normal transaminases. This evidence concerns the gene GPT and liver disorder.