The term "dystonia genes" is a little misleading. Several genes have been associated with certain forms of dystonia. Every human being, whether they have dystonia or not, has theses genes. The genes themelves, in their normal states, do not cause dystonia. These genes become "dystonia genes" when they contain very specific mutations that change how the gene operates and trigger the onset of dystonia symptoms
Genes that are defective in some way cannot produce proteins correctly and therefore either cause disease directly or somehow influence the symptoms of the disease. Errors in genes are responsible for an estimated 3,000 to 4,000 clearly hereditary diseases, including certain forms of dystonia
At present researchers have recognized multiple forms of inheritable dystonia and have identified at least 13 genes or chromosomal locations responsible for the various manifestations including
DYT1 early-onset generalized dystonia
Dopa-responsive dystonia
Paroxysmal dystonias
X-linked dystonia-parkinsonism
Myoclonic dystonia
Rapid-onset dystonia-parkinsonism
Identifying these dystonia genes is important because it gives researchers the first tool to unravel the complicated series of biochemical events that causes dystonia symptoms. Once researchers have a better understanding of how and why symptoms develop, better treatments and therapeutic strategies will be developed
For example, researchers discovered that dopa-responsive dystonia is caused by a mutation in a gene that produces a specific enzyme that the body needs to make a chemical called “dopamine.” Dopamine is a neurotransmitter in the brain. A problem in the brain’s ability to produce or manage dopamine disrupts the ability of the nervous system to work properly. By understanding the precise neurotransmitter that was affected, it became clear that small doses of a medication called levodopa could be used to treat affected persons. Most forms of dopa-responsive dystonia respond dramatically to levodopa, and this would not have been confirmed without the gene research. These discoveries also suggest that other genes involved in the brain’s use of dopamine may cause variant forms of this disorder
