Hypomyelinating Leukoencephalopathy

Sir, Leukoencephalopathies in children are a heterogeneous group of disorders affecting the white matter of the brain, and often pose a major challenge to the treating physician for the appropriate aetiological diagnosis and management. Van der Knapp and others described a peculiar form of leukoenchalopathy affecting the basal ganglia and cerebellum in children with extensive hypomyelination; however, since that publication, few cases have been reported in the literature.1 The patients described had normal births and early development followed by an extrapyramidal movement disorder in the form of dystonia, spasticity, and ataxia, with global developmental regression. Magnetic resonance imaging (MRI) of the brain showed characteristic hypomyelination with atrophy of basal ganglia and cerebellum; however, the thalamus and globus pallidus were spared. The molecular basis for the diagnosis has never been established for this disease.4 However, histopathologyhas been able to confirm extensive myelin loss in the aforementioned areas of the brain.2 We report a two-year-old Nigerian boy with clinical and radiological features of hypomyelination, and mild atrophy of the basal ganglia and cerebellum.