This hereditary neurologic disorder affects hearing, vision, balance, and sensation. Early studies suggest that treatment with riboflavin (a B vitamin) has a beneficial effect.
Infants are usually clinically normal at birth but within a few years develop generalized muscle weakness and difficulty with balance. This results in breathing, swallowing and speech problems. Mental function is usually normal. Later in childhood wasting of muscles in the hands becomes evident along with abnormal curvature of the spine.
Hearing loss and decreased vision are common. Sometimes the eyes have jerky to-and-fro (nystagmus) movements and the optic nerve that carries visual signals to the brain may become pale.
A mutation (change) in a specific gene is responsible for this condition when it is present in both members of the pair (autosomal recessive inheritance). Parents who carry only one copy of the mutation are clinically normal but when both carry a copy each of their children have a 25% risk of inheriting two copies.
Infants seem to be normal at birth but the characteristic neurologic abnormalities present within a year or two which enables the diagnosis to be made. Pediatricians, neurologists, hearing specialists, and ophthalmologists may collaborate in the diagnosis and care of children with this condition.
The neurologic features are rapidly progressive and death from respiratory difficulties often occurs within several years.
Physical therapy and assisted breathing may be helpful. Dietary supplementation with riboflavin, a B vitamin, has been reported to be beneficial.