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Homocystinuria
Osmosis
Disease or Syndrome
homocystinuria
Subclass of:
Brain Diseases, Metabolic, Inborn; Connective Tissue Diseases; Hyperhomocysteinemia
Definitions related to homocystinuria:
  • A rare genetic disease that causes blood levels of homocysteine to rise too high.
    Harvard Dictionary of Health Terms
    Harvard Medical Publishing, 2011
  • An autosomal recessive inherited metabolic disorder caused by mutations in the CBS, MTHFR, MTR, and MTRR genes. It is characterized by abnormalities in the methionine metabolism and is associated with deficiency of cystathionine synthase. It results in the accumulation of homocysteine in the serum. It may affect the cardiovascular, musculoskeletal and the central nervous systems.
    NCI
    U.S. National Cancer Institute, 2021
  • An increased concentration of homocystine in the urine.
    Human Phenotype Ontology (HPO)
    The Human Phenotype Ontology Project, 2025
  • Autosomal recessive inborn error of methionine metabolism usually caused by a deficiency of CYSTATHIONINE BETA-SYNTHASE and associated with elevations of homocysteine in plasma and urine. Clinical features include a tall slender habitus, SCOLIOSIS, arachnodactyly, MUSCLE WEAKNESS, genu varus, thin blond hair, malar flush, lens dislocations, an increased incidence of MENTAL RETARDATION, and a tendency to develop fibrosis of arteries, frequently complicated by CEREBROVASCULAR ACCIDENTS and MYOCARDIAL INFARCTION. (From Adams et al., Principles of Neurology, 6th ed, p979)
    NLM Medical Subject Headings
    U.S. National Library of Medicine, 2025
  • Homocystinuria is a disorder of amino acid metabolism that is caused by a lack of the enzyme cystathionine beta-synthase, which is needed to metabolize homocysteine. This disorder can cause a number of symptoms, including decreased vision, intellectual disability, and skeletal abnormalities. Homocystinuria occurs when parents pass the...
    Merck Manuals
    Merck & Co., Inc., 2025
  • Homocystinuria refers to a group of inherited disorders in which the body is unable to process certain building blocks of proteins (amino acids) properly. This leads to increased amounts of homocysteine and other amnio acids in the blood and urine. The most common type of genetic homocystinuria, called CBS deficiency, is caused by the...
    NIH Genetic and Rare Diseases
    National Center for Advancing Translational Sciences
  • 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...
    Encyclopedia Britannica
    Encyclopedia Britannica, Inc., 2025
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This content should not be used in place of medically-reviewed decision support reference material or professional medical advice. Some terms may have alternate or updated definitions not reflected in this set. The definitions on this page should not be considered complete or up to date.

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