ACUTE URINARY RETENTION DUE TO A NOVEL COLLAGEN COL4A1 MUTATION

The gene COL4A1 encodes the α1 chain of type IV collagen, a basement-membrane protein implying vascular parietal strength. Mutations in the gene COL4A1 have been described in families with diffuse small-vessel disease of the brain, resulting in perinatal stroke, congenital porencephaly, extensive leukoencephalopathy, intracerebral hemorrhage, and retinal arteriolar tortuosity.1–4 Our observation extends the clinical and magnetic resonance (MR) phenotype of COL4A1 mutation. ### Case reports. A 21-year-old man without neurologic medical history presented with acute urinary retention. He had a right amblyopia due to a congenital strabismus surgically treated in childhood. Clinical examination showed brisk lower limb reflexes and a left Babinski sign. Blood pressure was normal. The Mini-Mental State Examination score was strictly normal. The patient declined further neuropsychological testing. Brain CT showed diffuse leukoencephalopathy and multiple supratentorial microcalcifications (figure, A). Brain MRI revealed widespread white matter hyperintensities on T2 and fluid-attenuated inversion recovery sequences, dilated perivascular spaces, and lacunar infarctions. Leukoencephalopathy involved the cerebral periventricular and cerebellar deep white matter (figure, B). Multiple microbleeds were seen on gradient echo sequences, involving brainstem and supratentorial white matter (figure, C). MR angiography of cervical and intracranial arteries was normal, as was spinal …