In the October 2013 issue of the journal Annals of Neurology, an international consortium of researchers sought to characterize the genetics of migrating partial seizures of infancy, a condition that has unknown causes and a condition with limited knowledge about its cause. They characterized DNA from affected and unaffected family members.
- Utilizing complex and novel genetic techniques, they identified two regions of linkage on chromosome 4P16.1-P16.3 and chromosome 11P15.4-PTER.
- They identified eight novel homozygous variants in the genes in these regions. Only one variant, SLC25A22. ,esulted in a change of a highly conserved amino acid, P.G110R, and was not present in control samples.
- This gene encodes a glutamate transporter with strong expression in the developing brain. They showed that the G110R mutation located in the transmembrane domain of the protein disrupts mitochondrial glutamate transport.
- Their data shows that migrating partial seizures in infancy is inherited and are a result of a novel, homozygous mutation in the SLC25A22 in the affected individuals.
- The data suggests that this gene is responsible for this condition, a severe epilepsy with few known etiologies.
- This gene has been implicated in the distinct syndrome of neonatal epilepsy with suppression bursts on the EEG and this particular syndrome is now added to this association.
by Joseph I. Sirven, MD
Last Reviewed: 12/12/2013