HBB 2305 INBORN ERRORS OF METABOLISM notes (1).doc - INBORN ERRORS OF METABOLISM Inborn errors of metabolism are rare genetic(inherited disorders in

HBB 2305 INBORN ERRORS OF METABOLISM notes (1).doc - INBORN...

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INBORN ERRORS OF METABOLISM Inborn errors of metabolism are rare genetic (inherited) disorders in which the body cannot properly turn food into energy. The disorders are usually caused by defects in specific proteins (enzymes) that help break down (metabolize) parts of food . This means that the gene is not going to form enzymes hence that specific enzyme activity will be affected. If the activity of enzyme is affected the biological reaction is blocked leading to accumulation of metabolites resulting to disease state . CARBOHYDRATE METABOLISM Inborn errors of carbohydrate metabolism can be classified according to the underlying enzyme defect in the following groups: Defects of glycogen degradation (which underlie the glycogen storage diseases) Defects of galactose metabolism Defects of fructose metabolism Defects of pyruvate metabolism Defects of gluconeogenesis All classic disorders of carbohydrate metabolism result from a specific enzyme defect. Clinical manifestations are variable and range from occasional innocuous hypoglycemia to severe cognitive impairment and death within a few weeks of birth . Newborn screening enables the early detection of metabolic diseases and early initiation of appropriate dietary restrictions helps prevent disease manifestations. Inborn errors of Galactose metabolism Galactosemia is accumulation of galactose in blood ) is a rare genetic metabolic disorder that affects an individual's ability to metabolize the sugar galactose properly. Galactosemia is a disorder that affects how the body processes a simple sugar called galactose. A small amount of galactose is present in many foods. It is primarily part of a larger sugar called lactose, which is found in all dairy products and many baby formulas. The signs and symptoms of galactosemia result from an inability to use galactose to produce energy. Types of galactosemia These conditions are each caused by mutations in a particular gene and affect different enzymes involved in breaking down galactose. Classic galactosemia , also known as type I, is the most common and most severe form of the condition. If infants with classic galactosemia are not treated promptly with a low-galactose diet, life-threatening complications appear within a few days after birth. Affected infants typically develop feeding difficulties, a lack of energy (lethargy), a failure to gain weight and grow as expected (failure to thrive),
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yellowing of the skin and whites of the eyes (jaundice), liver damage, and abnormal bleeding . Other serious complications of this condition can include overwhelming bacterial infections ( sepsis ) and shock. Affected children are also at increased risk of delayed development, clouding of the lens of the eye ( cataract ), speech difficulties, and intellectual disability . Females with classic galactosemia may develop reproductive problems caused by an early loss of function of the ovaries (premature ovarian insufficiency).
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  • Summer '19
  • deficiency, autosomal recessive disorders, Inborn errors of metabolism

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