homocystinuria

      hereditary metabolic disorder involving methionine, a sulfur-containing essential amino acid. The metabolic sequence of methionine normally begins with its stepwise conversion to homocysteine, cystathionine, and cysteine, successively, each step being carried out by a specific organic catalyst, or enzyme. In homocystinuria, the defective enzyme is cystathionine synthetase, which normally converts homocysteine to cystathionine. As a result, abnormally high concentrations of homocysteine and its precursor, methionine, are found in the blood plasma. Symptoms of homocystinuria include mental retardation; displacement of the lenses of the eyes; shuffling gait; fine, sparse hair; skeletal deformations; and sometimes fatal episodic obstruction of blood vessels with clots. The joints tend to have restricted mobility rather than hyperextensibility. Dietary therapy, with methionine restriction and cystine supplementation (cystine is the oxidized form of cysteine) is apparently beneficial. Homocystinuria is believed to be transmitted recessively: unaffected carriers of the trait who mate can expect, on the basis of chance, to have one affected offspring out of four births.

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Universalium. 2010.

Look at other dictionaries:

  • Homocystinuria — Classification and external resources Homocysteine ICD 10 E72 …   Wikipedia

  • homocystinuria — homocystinuria. См. гомоцистинурия. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Homocystinuria — A genetic disease due to an enzyme deficiency. Among other events, there is a buildup of the amino acid homocystine. Progressive mental retardation is common in untreated cases. The finding of vascular disease and premature arteriosclerosis in… …   Medical dictionary

  • homocystinuria — Recessive condition in which the enzyme (cystathione synthetase) that converts homocysteine and serine into cystathione, a precursor of cysteine, is missing. Deficiency of this enzyme has widespread consequences in connective tissue, circulation… …   Dictionary of molecular biology

  • homocystinuria — noun An inherited metabolic disorder characterised by the presence of homocysteine in the urine …   Wiktionary

  • homocystinuria — ho·mo·cys·ti·nu·ria …   English syllables

  • homocystinuria — n. an inborn error of metabolism, inherited as an autosomal recessive trait, caused by an enzyme deficiency resulting in an excess of homocysteine in the blood and the presence of homocystine in the urine. Clinically affected individuals are… …   The new mediacal dictionary

  • homocystinuria — ˌhōməˌsistə̇ˈn(y)u̇rēə, ˌhäm noun Etymology: New Latin, from English homocystine + New Latin uria : a metabolic disorder inherited as a recessive autosomal trait, caused by deficiency of an enzyme important in the metabolism of homocystine with… …   Useful english dictionary

  • гомоцистинурия — (homocystinuria; гомоцистин + греч. uron моча) наследственная болезнь, обусловленная нарушением обмена метионина вследствие недостаточности L сериндегидрогеназы с накоплением в тканях гомоцистина; клинически проявляется нарушениями формирования… …   Большой медицинский словарь

  • Гомоцистинури́я — (homocystinuria; гомоцистин + греч. uron моча) наследственная болезнь, обусловленная нарушением обмена метионина вследствие недостаточности L сериндегидрогеназы с накоплением в тканях гомоцистина; клинически проявляется нарушениями формирования… …   Медицинская энциклопедия

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