Genetic and environmental backgrounds responsible for the changes in the phenotype of MS in Japanese subjects

Jun Ichi Kira

Research output: Contribution to journalReview article

7 Citations (Scopus)

Abstract

There are two distinct phenotypes of multiple sclerosis (MS) in Asians, manifesting as opticospinal (OSMS) and conventional (CMS) forms. In Japan, the results of four nationwide surveys of MS conducted between 1972 and 2004 have revealed a four-fold increase in the estimated number of clinically definite MS patients in 2003 compared with 1972; a shift in the peak age at onset from the early 30s in 1989 to the early 20s in 2003; a successive proportional decrease in optic-spinal involvement in clinically definite MS patients; an increase in the number of CMS patients with Barkhof brain lesions with advancing birth year and a decrease in the number of OSMS patients with LESCLs. These findings suggest that MS phenotypes are drastically altered by environmental factors such as latitude and "Westernization". Helicobacter pylori infection rates, reflecting sanitary conditions in infancy, are significantly different between CMS and OSMS patients. Both phenotypes show distinct HLA class II gene associations. Therefore, changes in environmental factors may have differentially influenced susceptibility to each disease subtype, given that disease susceptibility is only partly genetically determined.

Original languageEnglish
Pages (from-to)188-195
Number of pages8
JournalMultiple Sclerosis and Related Disorders
Volume1
Issue number4
DOIs
Publication statusPublished - Oct 1 2012

All Science Journal Classification (ASJC) codes

  • Neurology
  • Clinical Neurology

Fingerprint Dive into the research topics of 'Genetic and environmental backgrounds responsible for the changes in the phenotype of MS in Japanese subjects'. Together they form a unique fingerprint.

  • Cite this