There may be an association between natural differences (known as polymorphisms) in a gene called ADAM10 and temporal lobe epilepsy, according to new research led by Dr Keshen Li from Jinan University in China.The study, published in the scientific journal Frontiers in Neurology, is the first that shows such an association and suggests that by analysing these natural differences early on, it could be possible to predict someone’s risk of temporal lobe epilepsy.The team of researchers examined the regulatory region of the ADAM10 gene in 496 people with temporal lobe epilepsy and in 528 healthy volunteers. They saw that in people with temporal lobe epilepsy the frequency of ‘component‘ A in the DNA was consistently increased compared to healthy controls, who had a higher frequency of component C at the same position on the DNA.Further analyses suggested that the presence of A on both chromosomes at that location could be a factor that makes people more susceptible to temporal lobe epilepsy, whilst having one A and one C could be protective against generalised tonic-clonic seizures and drug resistant temporal lobe epilepsy.It is important to note that all of the people recruited to this study were of Han Chinese decent and that the genetic polymorphisms might be different in other ethnic groups. The authors write: “Caution should be exercised before generalizing these findings to other ethnic populations.” However, at the very least these findings will guide future research that could ultimately lead to new diagnostic techniques and better treatments for temporal lobe epilepsy.It is known that there are as many as 6,771 polymorphisms in the ADAM10 gene, which encodes for a cell-surface protein crucial in Alzheimer’s disease. Two of these differences, found in the regulatory region of the gene, are particularly important because they have been shown to decrease or ‘downregulate’ the expression* of the ADAM10 gene and give rise to epileptic seizures in Alzheimer’s disease.Experiments in rodents have also shown that downregulating ADAM10 results in repetitive seizures, which may well mean that low levels of ADAM10 can also cause seizures in people. A ‘reverse’ experiment showed that in mice where ADAM10 was mildly overexpressed, induced seizures were less severe and recovery times were shorter, again suggesting that ADAM10 may be protective against seizures.* The term ‘gene expression’ refers to the process by which information from a gene is used to create a functioning gene product, very often a protein.Author: Dr Özge ÖzkayaClick here for more articles about brain science including genetics.