Table 1.

Demographic information of the initial GEMS cohort of first-degree family members (n=1696).

Parameter	Percentage of the Study Population
Female	79.2%
Race (Self-reported)
European descent, non-Hispanic	95.5%
African American	1.7%
Multi-racial	1.8%
Others	1.0%
Born in continental US	96.8%
Existing MS diagnosis at enrollment	6.7%
Smoking status
Smoking, current	8.1%
Smoking, ever	26.9%
History of infectious mononucleosis	25.0%
	Mean (SD)
Follow-up Duration (years) *	2.1 ± 0.77

^*As of June 2014