As of June 30, 2021, the Registry has 9,835 twin pairs (19,670 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
| Age group | % at enrollment | % today |
|---|---|---|
| 9 and younger | 6.0 | 4.1 |
| 10-19 | 21.0 | 2.5 |
| 20-29 | 20.2 | 7.8 |
| 30-39 | 15.1 | 27.8 |
| 40-49 | 12.1 | 17.0 |
| 50-59 | 12.1 | 13.5 |
| 60-69 | 10.0 | 13.5 |
| 70+ | 3.6 | 13.8 |
Ethnicity
Hispanic/Latino: 4.2%
Race
One race: 96.7%
White: 89.6%
Black or African American: 1.9%
American Indian or Alaska Native: 0.6%
Asian: 2.6%
Native Hawaiian or Other Pacific Islander: 0.4%
Some other race: 1.5%
Two or more races: 3.3%
White and Black or African American: 0.5%
White and American Indian or Alaska Native: 0.8%
White and Asian: 0.9%
Two or more other races: 1.1%
Zygosity
Identical: 54.0%
Fraternal: 46.0%
Sex
Male/Male pairs: 28.1%
Female/Female pairs: 50.5%
Male/Female pairs: 21.4%
Zygosity/Sex
MZ Male pairs: 19.1%
MZ Female pairs: 34.9%
DZ Male pairs: 8.9%
DZ Female pairs: 15.7%
DZ Male/Female pairs: 21.4%
Where are our members located?
