Hereditary Neurodegenerative Disorders

This category includes the eight identified leukodystrophies metachromatic leukodystrophy, Refsum's disease, adrenoleukodystrophy, Krabbe's disease, phenylketonuria, Canavan disease, Pelizaeus-Merzbacher disease and Alexander's disease. The first six are storage disorders. The lack or the malfunctioning of an enzyme causes a toxic buildup of chemical substances. In Pelizaeus-Merzbacher disease myelin is never formed (dysmyelination) because of a mutation in the gene that produces a basic protein of CNS myelin. The etiology of Alexander's disease remains largely unknown.

The clinical course of hereditary demyelinating disorders, which usually tend to manifest themselves in infancy or early childhood, is tragic. Previously normal children are deprived, in rapid progression, of sight, hearing, speech, and ambulation. Equally tragic is their prognosis: death within a few years.

A number of government agencies and private foundations currently support research on various myelin diseases. Some efforts focus on identifying the cause of individual diseases; others are directed toward developing therapies for arresting disease progress or preventing onset.

In contrast, little attention is being given to the problems of repairing damage already done by the disease and of restoring lost function. Laboratories working on remyelination are relatively few in number and their programs are under-funded. In addition, rivalry among researchers is intense. Laboratories tend to work in isolation, learning of each other's progress through medical journal articles which are usually published a year or two after experiments are completed. This fragmented approach is clearly unsuitable to regenerating CNS myelin, a complex task which requires multi-disciplinary skills.