The age at onset is typically in the mid-teens to the mid-40s. There is no seasonal variation. The annual incidence of transverse myelitis is 0.46 in 100,000 in the United States (Jeffery et al 1993), at least 0.6% in New Zealand (Young et al 2009), and 0.13 in 100,000 in Israel (Berman et al 1981). Ashkenazi (European-American born) and Sephardic (Afro-Asian born) Jews born outside of Israel have an identical risk of developing transverse myelitis, but birth in Israel halves the eventual risk (Berman et al 1981). Black African and Eastern Asian ancestry predisposes to a Devic-like picture, with more frequent myelitis and more disability than with the Western form of multiple sclerosis.