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Multiple sclerosis trait: the premorbid stage of multiple sclerosis. A hypothesis

C M Poser1

  • 1Department of Neurology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA. cposer@bidmc.harvard.edu

Acta Neurologica Scandinavica
|March 16, 2004
PubMed

Insights

Monozygotic twins with multiple sclerosis (MS) suggest a shared "multiple sclerosis trait" premorbid stage. Environmental factors trigger this trait to develop into clinical MS, explaining discordance even in identical twins.

Area of Science:

  • Neuroimmunology
  • Genetics
  • Environmental Medicine

Background:

  • Multiple sclerosis (MS) exhibits low concordance rates in monozygotic (MZ) twins.
  • This suggests a premorbid condition distinct from asymptomatic MS.

Purpose of the Study:

  • To investigate the concept of a shared systemic condition, the "multiple sclerosis trait," in MZ twins.
  • To differentiate this trait from asymptomatic MS and understand its role in disease development.

Main Methods:

  • Analysis of concordance rates in monozygotic twins.
  • Conceptual framework development for the "multiple sclerosis trait."
  • Distinguishing premorbid stages from clinical disease.

Main Results:

  • Low MZ twin concordance suggests a shared "multiple sclerosis trait" exists before clinical MS.
  • This trait arises from an antigenic challenge in genetically susceptible individuals.
  • The trait is distinct from asymptomatic MS and may not progress to disease without environmental triggers.

Conclusions:

  • The "multiple sclerosis trait" represents a premorbid stage influenced by genetics and environmental factors.
  • Environmental triggers are necessary to convert the trait into clinically apparent MS.
  • Discordance in MZ twins reflects differential environmental influences on trait expression.

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