Molecular basis of neurodegeneration and amyotrophic lateral sclerosis My laboratory is studying disorders of the human neurodegeneration. The focus of our research is on the prototypic neurodegenerative disorders of the upper and lower motor neuron, such as amyotrophic lateral sclerosis (ALS), the spinal muscular atrophies (SMA) and familial spastic paraplegias (FSP). These disorders affect both the upper and lower motor neuron (ALS), the lower motor neuron only (SMA) and primarily the upper motor neuron (FSP).
We have used the tools of molecular genetics, cell biology and clinical neurology to establish loci of dominant and recessive amyotrophic lateral sclerosis, autosomal recessive and dominant spastic paraplegias and identified mutations in the gene for Cu,Zn superoxide dismutase in families with familial amyotrophic lateral sclerosis. Our transgenic mouse model, over expressing the mutant but not the wild type SOD1 results in degeneration of motor neurons and suggests a toxic gain of function of mutant SOD1 as a cause of ALS. Recently, we have shown that the entire SOD1 molecule is not necessary for its toxic function. In addition, a genetic locus for dominant ALS has been identified on the X-chromosome.
We have cloned, the human a-tocopherol transport gene and identified its chromosomal localization. Mutations in this gene result in a syndrome of ataxia and neuronal degeneration. The relationship of vitamin E to neuronal degeneration is under investigation. Work on genes causing scapuloperoned muscular atrophy and dominantly inherited mitrochondrial myopathy is also underway. Our work is thus focused on understanding the pathogenesis of neurodegeneration and bridging the gap between the laboratory, clinic, and therapy.