Two new genetic associations to amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, are reported in a study published online this week in Nature Genetics. The identified associations may suggest pathways involved in the characteristic neural degeneration.
ALS is a progressive neurodegenerative disorder characterized by loss of motor neurons in the spinal cord, brainstem and motor cortex of the brain, which leads to atrophy of the muscles and eventually paralysis.
Leonard van den Berg and colleagues report a large scale genome-wide association study to sporadic ALS, the most common form of the disease. In addition to replicating some of the previous genetic associations to this disorder, they identify two genetic regions newly associated with ALS. One of the candidate genes is UNC13A, encoding a presynaptic protein that is found within central and neuromuscular synapses. This protein regulates the release of neurotransmitters, which suggests a mechanism for its involvement in the characteristic motor neuron degeneration associated with the disease's progression. The second genetic association occurs at a region previously implicated in individuals with a familial form of ALS and a specific type of dementia.