homocystinuria

Spontaneous
cerebral venous thrombosis in a two-year-old infant with Cystathionine β-synthase deficiency. (B) Sagittal contrast-enhanced 3D-TFE T1-weighted image confirming this extensive thrombus (arrows).
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Spontaneous
cerebral venous thrombosis in a two-year-old infant with Cystathionine β-synthase deficiency. The high-density cortical vein thrombus (arrowhead) can be seen and reaches the still open superior sagittal sinus (arrows).
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Spontaneous
cerebral venous thrombosis in a two-year-old infant with Cystathionine β-synthase deficiency. Axial contrast-enhanced CT images made 12 hours after Fig. 1. The thrombus (arrowhead) in the cortical vein can be followed to the lateral part of the enhancing open superior sagittal sinus (arrows)
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Spontaneous
cerebral venous thrombosis in a two-year-old infant with Cystathionine β-synthase deficiency. (A) Axial contrast-enhanced 3D-TFE T1-weighted image showing the increased thrombus size with now occlusion of a long segment of the superior sagittal sinus (arrows) and multiple thrombosed cortical veins (arrowheads).
www.eurorad.org • CC by-nc-sa-4.0
Spontaneous
cerebral venous thrombosis in a two-year-old infant with Cystathionine β-synthase deficiency. (D) MR venography showing absence of contrast opacification of the superior sagittal sinus and multiple cortical veins (arrows). Dilated deep cerebral and ophthalmic veins (arrowheads) secondary to the thrombus.
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Radiopaedia • CC-by-nc-sa 3.0 • de

Homocystinuria is a rare congenital disorder of metabolism.

Clinical presentation

The disease may affect one or more of the systems below :

Pathology

A deficiency of the enzyme cystathionine-β-synthase causes classic homocystinuria whereby the metabolism of homocysteine to methionine is affected. It is inherited in a autosomal recessive fashion. Other forms of secondary homocystinuria can be seen in other rare inborn metabolism disorders (e.g. methylenetetrahydrofolate reductase deficiency) .

Markers

High levels of plasma total homocysteine and methionine are present . Neonatal screening heel-prick tests typically include testing for homocystinuria.

Genetic testing

Genetic testing can be used to confirm homocysteinuria.

Radiographic features

No radiographic features are specific for homocystinuria and the diagnosis is made through genetic and laboratory testing. Rarely, some associations of the disease may be visible on imaging (e.g. spontaneous pneumothorax or thromboembolism) .

MRI

Although not specific, MRI brain may show :

  • multiple cortical-subcortical infarctions in the cerebellar and cerebral hemispheres of varying ages
  • diffuse white matter signal intensity abnormalities may be present secondary to demyelination
  • occlusive vessel or dural sinus disease on MR angiography or venography
  • lens dislocation

Treatment and prognosis

Mortality in homocystinuria mostly occurs from premature cardiovascular disease .

Differential diagnosis

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