The National Longitudinal Study of Adolescent Health (Add Health) twin data.

This article describes the design and data availability for samples of genetic pairs in the National Longitudinal Study of Adolescent Health (Add Health). Add Health provides unique samples of genetic pairs that are nationally representative and followed longitudinally from early adolescence into young adulthood with 3 in-home interviews and a 4th interview planned for 2007 to 2008. The design of Add Health included an embedded genetic sample of more than 3000 pairs of individuals with varying genetic resemblance, including monozygotic twins, dizygotic twins, full siblings, half siblings, and unrelated siblings who were raised in the same household. Add Health has collected rich longitudinal social, behavioral, and environmental survey data, as well as buccal cell DNA from a subsample of the genetic sample (N = 2612). Add Health has an enlightened dissemination policy and to date has released phenotype and genotype data to more than 3000 researchers in the scientific community.