COL4A1 AND COL4A2 VARIANT ANALYSIS IN BRAIN SMALL-VESSEL DISEASE WITH HAEMORRHAGE
Brain small-vessel disease manifests as infantile hemiparesis, seizures, single or recurrent hemorrhagic stroke, ischemic stroke, and isolated migraine with aura. Affected individuals also have leukoencephalopathy, observed during magnetic resonance imaging (MRI) imaging. They may also experience seizures and migraine headaches accompanied by auras.
Some people with COL4A1-related brain small-vessel disease have Axenfeld-Rieger anomaly, involving underdevelopment and eventual tearing of the iris and a pupil that is not in the center of the eye. Affected individuals may also have cataracts and arterial retinal tortuosity. Arterial retinal tortuosity can cause episodes of bleeding within the eye following any minor trauma to the eye, leading to temporary vision loss.
The severity of the condition varies greatly among affected individuals. Other COL4A1-related disorders include Hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC) syndrome and Familial Porencephaly, characterised by fluid-filled cavities in the brain, which typically manifests as infantile hemiparesis, seizures, and intellectual disability.
Please note: for NHS patients in England this test has been superseded with gene panel testing (please contact your local Genomic Laboratory Hub for further information). Single gene testing is only available if required urgently for clinical management.
The laboratory participates in the European Molecular Genetics Quality Network (EMQN) sequencing scheme.