GPT and obesity due to melanocortin 4 receptor deficiency: They demonstrated that elevated levels of ALT and/or AST > 50 U/L were present in 11% of patients, predominantly in boys (boys vs girls; 14.4:7.4%; P < 0.001), extreme obesity (obese vs extremely obese; 9.5:17.0%; P < 0.001) and adolescent age (< 12 vs > 12 years; 8:12%; P < 0.001; adjusted for BMI).