<prompt> An 8 days old neonate presents with hypoglycemia Glucose - 17 mg and jaundice is diagnosed to have metabolic disorder. Most likely diagnosis:HypothyroidismGalactosemiaGlycogen storage diseaseFatty acid oxidation defect  <response>: B i.e. GalactosemiaRef: Nelson, Textbook of Pediatrics, 20th edition, page 726Manuai of Neonatal Care, ClohertyExplanation:GalactosemiaDue to deficiency of galactose-1-phosphate uridyltransferase GALT.Newborn develop symptoms after ingestion of lactose glucose-galactose disaccharide through a standard formula or breast milk.Clinical featuresVomiting, diarrhea, feeding difficulties,Hypoglycemia.Jaundice, hepatosplenomegaly, liver dysfunction,Renal tubulopathy.Lethargy, irritability, seizures,Oil drop cataract.Increased risk of Escherichia coli neonatal sepsis.Galactose is elevated in plasma, and galactose-1-phosphate is elevated in red blood cells.Newborn screening programs screen for galactosemia either by measuring GALT enzyme activity or galactose levels.Substituting a soy-based formula for breastfeeding, later, a galactose-restricted diet.Also NotelEMs presenting with hypoglycemia:Organic acidurias,Defects of fatty acid oxidation.Defects of gluconeogenesis glycogen storage disease type I or fructose-1, 6-bisphosphatase deficiency.Nonketotic hypoglycemia is the hallmark of defects in fatty acid oxidation while hypoglycemia associated with metabolic acidosis and ketones suggests an organic acidemia or defect of gluconeo- genesis.DefectClinical featuresLab featuresTreatmentFatty acid oxidation defect Hypoketotic hypoglycemia Lactic acidosis Cardiomyopathy HepatopathyAbnormal acylcarnitine profileGlucose infusion, carnitine 50- 100 mgkgday, and avoid fastingGlycogen storage disease Typically presents at 3 to 6 months of age Poor growth Hypoglycemia HepatomegalyLactic acidosis, hypertriglyceridemia and hyperuricemiaAvoidance of fasting Frequent or continuous feeding 