More MS news articles for Dec 2001

Genetic Factors Contribute to Clinical Phenotype in MS

LONDON (Reuters Health) Dec 07 - Disease outcomes in sibling pairs with multiple sclerosis are similar, suggesting genetic influences on the way in which the disease progresses, investigators in the UK report.

Dr. Alastair Compston, of the University of Cambridge, and associates recruited 262 pairs of co-affected siblings from 250 families. As they report in the Journal of Neurology, Neurosurgery and Psychiatry for December, once the disease course had become established in both siblings of a pair, they observed significant concordance between the siblings on measures of disability, progression, and handicap.

The type of disease course relapsing-remitting, primary progressive, or secondary progressive was the same in 50% of sibling pairs.

"All this tells one, nothing more and nothing less, is that here is some evidence that some genetic factors tend to influence the course of MS," Dr. Compston told Reuters Health.

"Perhaps this is the expression of the hidden rounds of inflammation, demyelination, and axonal loss, which although initiated in different regions of the neuraxis, subsequently display similar tempos of progression and coalesce with the same outcome in any two siblings," Dr. Compston and his colleagues surmise in the journal.

There was no significant concordance between siblings for presenting symptoms, main presenting site, age of onset, or relapse pattern over the year preceding analysis.

"What we showed is that MS starts in a rather erratic way, so that there is no similarity in presenting symptoms between siblings," Dr. Compston explained. "The nature of the illness is that it affects many different paths of the nervous system randomly, so there's no reason to think that the very first event that shows itself will be identical for genetic reasons."

"But as time goes by, symptoms of [those in affected families] tend to even out," he added. "So in the end, the likelihood is greater than chance for the paths [of two related siblings] to look alike."

These findings should help clinicians when counseling patients in whose families MS has already manifested, Dr. Compston maintained.

"Until now clinicians have taken the position that one could not provide guidance on the likely course in an individual even if they had an affected relative," he said. "Now we can modify that position somewhat. If your sibling has a mild form of illness, then one can be cautiously optimistic on your part as well."

"But these are statistical statements, which are unreliable when applied to the individual," he cautioned.

J Neurol Neurosurg Psychiatry 2001;71:757-761.

Copyright © 2001 Reuters Ltd