Monday, July 24, 2000; 9:58 AM
NEW YORK-Both environmental and genetic factors are thought to contribute to multiple sclerosis, the leading cause of neurological disability in young adults. Now, from researchers in Austria come study results suggesting that the presence of a particular gene variant may influence the severity of multiple sclerosis (MS).
Dr. Franz Fazekas, of Karl-Franzens University in Graz, led a team of investigators looking at the implications of carrying the E4 variant of the apoE gene.
Writing in the Journal of Neurology, Neurosurgery and Psychiatry, the authors explain that they "obtained blood samples for apoE genotyping from all patients admitted to our multiple sclerosis outpatient clinic."
ApoE is a protein involved in the transport of cholesterol and other fatty substances. In MS, the fatty tissue called myelin that envelops nerves is often progressively destroyed. It has been theorized that apoE might play a role in the process, perhaps by "redistributing" fatty remnants of myelin or even partially restoring myelin, depending on the which of the three main gene variants is present.
The researchers studied relationships between patients' apoE types and signs of MS on magnetic resonance imaging (MRI) studies of their brains. MRI is useful for detecting visually the damage associated with MS.
The investigators found that more severe damage was associated with the presence of the E3/E4 gene variant. The severest damage--colloquially termed 'black holes'--was nearly twice as common in these patients than in people with other apoE combinations, such as E3/E3 or E2/E3.
Patients with the E3/E4 variant "tended to have more aggressive disease with greater disability and a higher number of relapses experienced in a shorter period of time," according to the report.
However, it is not clear if the E4 gene is associated with a more damaging demyelination process or if it is "a consequence of less efficient repair," Fazekas and colleagues point out.
What is clear, the authors conclude, is that more research is needed
to clarify the contribution of apoE genes to the MS disease process.
© 2000 Reuters