hyperglycinemia

Elevated plasma glycine concentration.

- ketotic h. an inherited metabolic defect which results from a deficiency of propionyl Coenzyme A carboxylase, the enzyme that converts propionate to methylmalonate; the enzyme requires biotin as a cofactor; clinically, affected infants have overwhelming illness, with lethargy, metabolic acidosis with ketosis, hypotonia; coma and seizures typically develop with early death; propionic acid is markedly elevated in plasma and urine; there is also hyperammonemia, and elevated levels of other metabolites as well, including glycine, hence the original name for the syndrome. SYN: methylmalonic acidemia, propionic acidemia.

- nonketotic h. [MIM*238300] an inborn error of glycine metabolism, due to a deficiency of glycine dicarboxylase P protein (GCSP), a component of glycine cleavage system; characteristically overwhelming disease in the newborn period, with coma, seizures and death, or, less often, gradual onset with failure to thrive, focal seizures, and mental retardation; there is massive elevation of plasma glycine, with increased levels in cerebrospinal fluid and urine; plasma hyperosmolality, severe dehydration occur without ketoacidosis; autosomal recessive inheritance; caused by mutation in the GCSP gene on chromosome 9p.

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hy·per·gly·ci·ne·mia or chiefly Brit hy·per·gly·ci·nae·mia .hī-pər-.glī-sə-'nē-mē-ə n a hereditary disorder characterized by the presence of excess glycine in the blood

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hy·per·gly·cin·e·mia (hi″pər-gli″sĭ-neґme-ə) excess of glycine in the blood or other body fluids. Called also glycinemia.