II. Pathophysiology

  1. Inherited enzyme deficiency
  2. Effects
    1. Intimal fibrosis and Fiber destruction
      1. Destroys arterial elastic fibers
      2. Destroys Zonular fibers of the lens
    2. Fatty Liver infiltration
    3. Gliosis and focal necrosis of the Midbrain

III. Etiology

  1. Cystathionine B-synthase deficiency
  2. Methylene tetrahydrofolate reductase deficiency
  3. Methionine synthase defect
  4. Vitamin B12 transport or coenzyme defect

IV. Signs

  1. Mental Retardation
  2. Seizures
  3. Cataracts
  4. Lenticular subluxation
  5. Sparse hair
  6. Arachnodactyly
  7. Pectus Excavatum
  8. Long and thin trunk, arms and legs
  9. Thromboembolic phenomenon

V. Labs

  1. Increased levels Homocysteine and methionine
    1. Present in CSF, Plasma and Urine

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Ontology: Homocystinuria (C0019880)

Definition (MSH) 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)
Definition (NCI) 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.
Definition (CSP) 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 varis, 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.
Concepts Disease or Syndrome (T047)
MSH D006712
ICD10 E72.11
SnomedCT 190709008, 11282001
LNC LP56981-1
Japanese ホモシスチン尿, ホモシスチンニョウ, ホモシスチン血症, シスタチオニン合成酵素欠損, シスタチオニン合成酵素欠損症, ホモシスチン尿症, 高ホモシスチン血症
Swedish Homocystinuri
English Homocystinuria, cystathionine synthase deficiency, homocystinuria, homocystinuria (diagnosis), Cystathionine synthase deficiency, Homocystinuria [Disease/Finding], Homocystinuria (disorder), Homocystinuria, NOS, Homocystinuria [Ambiguous]
Czech homocystinurie, Homocystinurie
Finnish Homokystinuria
Russian GOMOTSISTINURIIA, ГОМОЦИСТИНУРИЯ
Polish Homocystynuria
Hungarian Homocystinuria
Norwegian Homocystinuri
Spanish homocistinuria (trastorno), homocistinuria, Homocistinuria
Dutch homocystinurie, Cystinurie, homo-, Homocystinurie
German Homocystinurie, Homozystinurie
French Homocystinurie
Italian Omocistinuria
Portuguese Homocistinúria