[Linkage analysis in an extended multigenerational family segregating for idiopathic epilepsy]

Linkage analyses enable us to identify the loci that bestow susceptibility to certain diseases which are assumed to have a genetic aetiology by determining the cosegregation of alleles of specific markers within families.

The aim of this study was to determine whether there is generalised idiopathic epilepsy (GIE) susceptibility in the 8q22.1 -q24.23, 16p13.3 and 21q22.3 regions within an extended multigenerational family belonging to the Paisa community in Antioquia, a genetic isolate located in Colombia segregating for GIE with a strong capacity for detecting linkage.

A family with a number of individuals affected by idiopathic epilepsy who visited the Instituto Neurológico de Antioquia was selected for study. An affected individual was required to have been diagnosed by a neurologist as suffering from non-myoclonic idiopathic epilepsy or partial idiopathic epilepsy. All patients suspected of suffering from idiopathic epilepsy were submitted to video monitoring in order to characterise the seizures electroencephalographically.

Of the 106 individuals in this family that were included in the family tree, 76 were genotyped, 15 of whom were affected by generalised clonic tonic seizures and six were considered to be possibly affected. Results of the lod score were significantly negative for all the markers in relation to each model that was considered.

The possibility of the genes located in the 8q22.1 -q24.23, 16p13.3 and 21q22.3 regions being responsible for the familial aggregation of GIE in this family was ruled out, which is in accordance with claims made in previous studies conducted on other families.