A study published in the November issue of Nature Genetics by investigators from the Research Institute of the McGill University Health Centre (MUHC) identifies a gene that underlies a neurological disorder affecting the brain and spinal cord. There is a high incidence of this condition in the Quebec population overall and 1 child in 2100 is born with the disorder in the Charlevoix and Saguenay-Lac-St-Jean regions.
"The SLC12A6 gene may be critical to the development of the nervous system," says Dr. Guy Rouleau MUHC neurologist and McGill University professor of neurology and neurosurgery. "A common mutation in this gene is found in patients who suffer from a particular type of neurological disorder, known as peripheral neuropathy associated with agenesis of the corpus callosum (ACCPN). Identifying and characterizing this gene will help in designing specifically targeted drugs for this disease"
The MUHC study analyzed DNA from 81 French Canadians with ACCPN and 110 French Canadians without this condition. Rouleau and collaborators found that the family members with ACCPN had a mutation in the SLC12A6 gene. This gene was not mutated in the unaffected family members. "The SLC12A6 gene is important for controlling the transport of small charged molecules like potassium or chloride in the brain," says Rouleau. "We determined that the mutation affects this function resulting in physical and mental deficiencies."
Peripheral neuropathy is a severe condition due to damaged nerves. Children with ACCPN have difficulties standing and walking without support. Their physical and mental abilities deteriorate with time and by adolescence, most individuals are confined to a wheelchair.
This study was done in collaboration with physicians at the Complexe hospitalier de la Sagamie, the Hopital de l'Enfant Jesus, and investigators at Vanderbilt University and Harvard University. It was supported by La Fondation des jumelles Coudé, the Canadian Institutes for Health Research and the US National Institutes of Health.