<prompt> A 3-day child vomits everything he feeds, has a distended abdomen diarrhoea. The urine is positive for benedicts test for reducing substance. The substance in urine isSucroseGlucoseGalactoseFructose  <response>: Characteristic symptom i.e., vomiting, distended abdomen and diarrhoea along with the presence of reducing a substance in the urine suggests the diagnosis of galactosemiaGalactosemia Galactosemia is a group of metabolic disorders which occurs due to defect in the metabolism of galactose.There is an inability to metabolise galactose which may be caused by a deficiency of any of the following enzymes: 1 Galactose-1 phosphate uridyl transferase most commonUDP-galactose-4-epimeraseGalactokinaseThe defect in galactose metabolism results in accumulation of galactose-1-phosphate and galactical that are thought to have direct toxic effect on the liver and other organs.Clinical featuresInfant appears normal at birth, however, becomes symptomatic a few days to weeks after initiating galactose containing feeds.Due to the accumulation of galactitol, damage to nerve tissue and liver occurs which causes:-Hepatic parenchymal disease- jaundice, hepatomegaly and ascitesMental retardation Vitreous haemorrhage Acidosis CataractSeizures Splenomegaly Hypoglycemia The accompanying GI symptoms are poor feedings, vomiting and diarrhea.Fanconi syndrome Aminoacidiuria, protein aria, phosphaturia may occur.DiagnosisUrine shows reducing sugar which can be detected byBenedicts reagentGlucose oxidase methodThe confirmatory diagnosis is made by the enzyme assay. 