GPT and obesity due to melanocortin 4 receptor deficiency: NASPHAN recommendations authors emphasize, that the screening test, i.e. ALT level assessment, should be performed from the age of 9-11 in children with obesity with body mass index(BMI) ≥ 85th percentile and additional risk factors, such as central obesity, insulin resistance, prediabetes and diabetes, dyslipidemia, sleep apnea or family history of NAFLD.