ST. PAUL, Minn -- Researchers have localized two new genes that are associated with fever-related seizures that occur in infancy and childhood, according to a study published in the April 24, 2007, issue of Neurology, the scientific journal of the American Academy of Neurology.

Identifying the genes responsible for febrile seizures could improve the understanding, treatment and even prevention of this disorder, said study author Rima Nabbout, MD, PhD, of the French Institute for Medical Research (INSERM) in Paris.

Fever-related (febrile) seizures are the most common seizure disorder in children and affect two to five percent of children by age six in the United States. For most children, the seizures do not cause permanent brain injury and occur only once or a few times. A small percentage of children go on to develop other seizure disorders such as epilepsy later in life.

The study examined four generations of a French family. Of the 51 people in the family, 13 had childhood febrile seizures. The febrile seizures stopped by the age of seven for all 13 children. However, six of the children developed epilepsy later in life. The 13 affected by the disorder and 13 additional family members not affected by the disorder took part in the genetic study.

The researchers used a technique called genetic linkage to determine which segments along chromosomes were shared by all family members who had febrile seizures. All of those affected shared a portion of chromosome 3. Chromosome 3 has not previously been reported to be associated with febrile seizures. The researchers also found that the family members who developed epilepsy shared another common segment on chromosome 18, providing evidence that the gene on chromosome 18 might act as a modifier gene. The gene on chromosome 18 may also be associated with febrile seizures.

Previous studies have identified four other loci that are associated with febrile seizures.