inborn error of metabolism (redirected from Defects in erythrocyte metabolism)

error /er·ror/ (er´er) a defect in structure or function; a deviation.

---

inborn error of metabolism  a genetically determined biochemical disorder in which a specific enzyme defect causes a metabolic block that may have pathologic consequences at birth or in later life.

---

inborn error of metabolism

n.

Any of a group of congenital disorders caused by an inherited defect in a single specific enzyme that results in a disruption or abnormality in a specific metabolic pathway.

---

Inborn error of metabolism

A rare enzyme deficiency; children with inborn errors of metabolism do not have certain enzymes that the body requires to maintain organ functions. Inborn errors of metabolism can cause brain damage and mental retardation if left untreated. Phenylketonuria is an inborn error of metabolism.

Mentioned in: Mental Retardation

---

inborn error of metabolism,

one of many abnormal metabolic conditions caused by an inherited defect of a single enzyme or other protein. Although people with such diseases are defective in only one protein, they generally display a large number of physical signs that are characteristic of the genetic trait and are related to excesses or deficiencies of the substrate on which the enzyme acts. The diseases are rare. Kinds of inborn errors of metabolism include galactosemia, glucose-6-phosphate dehydrogenase deficiency, Lesch-Nyhan syndrome, phenylketonuria, and Tay-Sachs disease.

observations Inborn errors of metabolism may be detected in the fetus in utero by the examination of squamous and blood cells obtained by amniocentesis and fetoscopy. Laboratory tests after birth often show higher than normal levels of particular metabolites in the blood and urine, such as phenylpyruvic acid and phenylalanine in phenylketonuria (PKU) and galactose in galactosemia. The values are higher in homozygous than in heterozygous carriers. Signs of the various defects are usually seen only in homozygous carriers.

interventions Treatment for some pathologic inborn errors may be removal of food in the diet containing the nondegradable metabolite to prevent its accumulation. Removal of dietary phenylalanine in PKU and galactose in galactosemia is effective in preventing the development of symptoms if treatment is begun early. In those cases of inborn errors of metabolism in which the nondegradable metabolite is endogenous, such as in the mucopolysaccharidoses, no treatment is available.

---

inborn

congenital; inherited or acquired before birth.

---

inborn error of metabolism

congenital disorders of metabolism. Includes cystinuria, fucosidosis, citrullinemia, mannosidosis, tyrosinemia and glycogenosis.

---

metabolism

the sum of the physical and chemical processes by which living organized substance is built up and maintained (anabolism), and by which large molecules are broken down into smaller molecules to make energy available to the organism (catabolism).

Essentially these processes are concerned with the disposition of the nutrients absorbed into the blood following digestion.

---

inborn error of metabolism

a genetically determined biochemical disorder in which a specific enzyme defect produces a metabolic block that may have pathological consequences at birth, as in maple syrup urine disease of calves, or in later life, e.g. in mannosidosis in calves. See also metabolic defect.

---

inborn error of metabolism

Any of the expanding group, now in the hundreds, of inherited metabolic and biochemical disorders, that are divisible into those affecting 1. Small molecules–eg, simple sugars, amino or organic acids, that often have an acute onset in infancy/childhood; 2. Large molecules–eg, ↑ in 'storage diseases'–eg, mucopolysaccharidoses and glycogen storage diseases that affect older children

Inborn errors of metabolism consequences  

Loss of certain molecules–eg, albinism–defect of tyrosinase or Ehlers-Danlos disease–defect of lysyl-hydroxylase or others of a vast array of enzymes

Accumulation of normal metabolites–eg, alkaptonuria–defect of homogentisic acid oxidase or galactosemia–defect of galactose-1-phosphate uridyl transferase

Transport defects–eg, cystinuria–dibasic amino acids or intestinal disaccharidase deficiency

Defects in erythrocyte metabolism–eg, glucose-6-phosphate dehydrogenase deficiency

Pigment defects–eg, acute intermittent porphyria

Defects in mineral metabolism–eg, Wilson's disease

Vitamin defects–eg, vitamin D-dependent rickets

Defects in intestinal absorption–eg, cystic fibrosis

Other defects of unknown origin–eg, achondroplasia