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 is aEUR'
Galactose Characteristic symptom i.e., vomiting, distended abdomen and diarrhea along with the presence of reducing substance in the urine suggests the diagnosis of galactosemia Benedict's Test Benedict's test is a biochemical test to detect reducing sugars. -Benedicts test detects the presence of aldehydes except (aromatic ones) and alpha hydroxyketones in a compound. All monosaccharides are reducing sugars i.e., they all have a free reactive aldehyde group and are positive on Benedicts. Some disaccharides such as fructose have alpha hydroxyl ketones and can reduce sugars. All other disaccharides are non reducing sugars and will not react with Benedict's solution Galactosemia Galactosemia is a group of inherited metabotic disorders in which an enzyme deficiency affects the normal metabolism of the sugar galactose Galactose is a monosaccharide Most of the galactose originates from the dairy products that contain lactose or milk sugar Lactose is a disaccharide that is catalyzed by the enzyme lactase into two monosaccharides i.e. lactose and glucose From the intestine the galactose is transpoed to liver where it is conveed to glucose phosphate, which can be used in several metabolic pathway. Conversion of Galactose to Gulose I phosphate occurs in several successive steps. A specific enzyme is required at each step Galactosemia occurs because of the deficiency of any of the enzymes involved in the metabolism of Galactose. The most common enzyme associated with galactosemia is the deficiency of the enzyme galactose -1- phosphate uridyl trans-ferase. The deficiency of the enzyme or the defect in the metabolism results in an accumulation of galactose -1- PO4 and galacticol that are thought to have direct toxic effect on the liver and other organs. Clinical features Infants with galactosemia appear normal at bih, however symptomsusually appear a few days to weeks after initiating galactose containing .feeds The early clinical features of severe galactosemia include liver dysfunction, manifested by jaundice and hypoglycemia, The accompanying gastrointestinal.findings are poor feeding, vomiting and diarrhoea. Due to the effect of galacticol toxicity on brain it may cause C.N.S symptoms to predominate which are irritability and seizures Diagnosis If galactosemia is suspected, urine should be tested simultaneously with Benedicts reagent and with Glucose oxidase method. - The Glucose oxidase method is specific for glucose, whereas - Benedict's reagent can detect any reducing substance -A negative glucose oxidase test with positive benedicts test suggests that a non glucose reducing substance is present. - With appropriate clinical findings this is most likely to be galactose Confirmatory diagnosis The confirmatory diagnosis is made by the enzyme assay.
Sucrose
Glucose
Galactose
Fructose