Behr syndrome

Behr syndrome is a rare neurological disorder defined by early-onset optic atrophy together with spinocerebellar degeneration, which produces ataxia, pyramidal signs, peripheral neuropathy and developmental delay. It usually begins in early childhood and progresses chronically. Eye findings include optic atrophy, nystagmus, scotoma and bilateral retrobulbar neuritis, and other features can include intellectual disability, myoclonic epilepsy, spasticity, contractures of the lower limbs and hypogonadotrophic hypogonadism. It is generally autosomal recessive, though carriers may show much milder symptoms and autosomal dominant inheritance has been reported in one family. Some reported cases carry mutations in the OPA1, OPA3 or C12ORF65 genes, which are known causes of pure optic atrophy or of optic atrophy with a movement disorder. Magnetic resonance imaging shows diffuse, symmetric white matter abnormalities, suggesting a white matter disorder with an unidentified biochemical basis. An autopsy of one affected sister showed central atrophy of the optic nerves and neuron loss in the lateral geniculate nucleus.