Genetics of Pediatric-Onset Motor Neuron and Neuromuscular Diseases

Diseases affecting the motor unit--which is composed of the motor neuron, its myelin sheath and its innervated muscle fibers--are a diverse, heterogeneous group having heterogeneous clinical presentations and genetic causes. Many of these disorders have a inherited component. In some cases, the genetics underlying a given neuromuscular/motor neuron disease, like spinal muscular atrophy (SMA) or Duchenne muscular dystrophy, are well characterized. There are, however, disorders whose genetic basis has yet to be determined or genetically characterized diseases which harbor novel mutations. The purpose of this genetic registry is to catalogue early-onset motor neuron and neuromuscular disorders and to determine their genetic bases. With samples obtained from this registry, the investigators will be able to provide a genetic diagnosis for a specific neuromuscular/motor neuron disease which will lead to better care for those patients affected by these diseases.

Many of these disorders have a wide spectrum of phenotypic variability. For example, the severity of SMA is quite variable even though it is caused by the loss of a single gene, i.e. survival motor neuron 1 (SMN1). The number of copies of the duplicated gene survival motor neuron 2 (SMN2) dictates phenotypic severity in SMA. In this study, the research team will also identify potential modifiers of phenotypic severity for specific disorders like SMA and Charcot-Marie-Tooth (CMT) disease. With the identification of novel modifier genes, the investigators will be able to more accurately predict disease outcomes and the investigators will also have novel targets for the development of therapeutic agents for these diseases.