These variations – or polymorphisms - could play a causative role in MS or be located near other polymorphisms that do play a causative role in the disorder. As such, they could be used as genetic markers for MS.
Alfonso Martinez and colleagues from the Hospital Clinico San Carlos, in Madrid, Spain, who carried out the research, suggest that EBF-1 might be involved in MS due to its role in axonal damage. "Axonal damage is a hallmark for multiple sclerosis," write the authors, and EBF is involved in the expression of proteins essential for axonal pathfinding. How axonal damage occurs in MS, however, is not well understood.
In their study, Martinez et al. compared the occurrence of a polymorphism at a single point in the DNA sequence of the gene EBF-1 – also called a single nucleotide polymorphism (SNP) - in 356 patients diagnosed with MS and 540 healthy individuals acting as controls. Both groups consisted of white Spanish individuals. The authors also compared the variants of a microsatellite – a highly variable, short stretch of non-coding DNA within the EBF-1 gene - in the two groups.
Their results show that patients with MS are more likely to carry the base adenine in the SNP analysed, than controls (p=0.02). In addition, one specific version (allele) of the microsatellite was more frequently found in MS patients than in controls (p=0.08). The authors confirmed this finding with a Transmission Disequilibrium Test: a study of the transmission rate of the allele in 53 patients and their parents, which showed that the allele was more likely to be present in both patients and their parents than other alleles.
MS is one of the most common neurological diseases in the Western world. It has traditionally been considered an autoimmune disorder of the central nervous system, and it is likely to be the result of a complex combination of genetic and environmental factors.
Article:
Early B-cell Factor gene association with multiple sclerosis in the Spanish population.
Alfonso Martinez, Ana Mas, Virginia de las Heras, Rafael Arroyo, Miguel Fernandez-Arquero, Emilio G de la Concha and Elena Urcelay
BMC Neurology 2005, 5:19 (28 October 2005)
Journal
BMC Neurology