As of June 30, 2018, the Registry has 9,546 twin pairs (19,092 individuals). New pairs are enrolled on a quarterly basis. Below is a detailed breakdown of the Twin Registry population, calculated from the survey that twins complete when they join the Registry.

Age
9 years old and under: 3.4%
10-19 years old: 1.3%
20-29 years old: 13.7%
30-39 years old: 26.8%
40-49 years old: 14.5%
50-59 years old: 12.9%
60-69 years old: 14.1%
70+ years old: 13.3%

Ethnicity
Hispanic/Latino: 3.9%

Race
One race: 97%
White: 90.2%
Black or African American: 2.0%
American Indian or Alaska Native: 0.6%
Asian: 2.4%
Native Hawaiian or Other Pacific Islander: 0.4%
Some other race: 1.4%
Two or more races: 3%
White and Black or African American: 0.5%
White and American Indian or Alaska Native: 0.8%
White and Asian: 0.8%
Two or more other races: 0.9%

Zygosity
Identical: 52.4%
Fraternal: 47.6%

Sex
Male/Male pairs: 28.3%
Female/Female pairs: 49.9%
Male/Female pairs: 21.8%

Zygosity/Sex
MZ Male pairs: 18.9%
MZ Female pairs: 33.5%
DZ Male pairs: 9.4%
DZ Female pairs: 16.4%
DZ Male/Female pairs: 21.7%

Where are our members located?