Among the SIBS families from whom at least one child was genotyped for the ALDH2 SNP rs671, all adoptive parents were white except for two step-parents of Asian descent, and one step-parent of mixed ethnicity. Alcohol use data were available for the elder non-biological siblings of 165 genotyped participants at IN, 160 elder siblings at FU1, and 128 elder siblings at FU2. As the SIBS study includes only sibling pairs, each genotyped participant had the possibility of only one elder sibling. Elder siblings were .22 to 4.73 years older than target siblings (M(SD) = 2.33(.91) years). Of these elder siblings, 17 were white, 145 were of Korean descent, and 3 were of mixed ethnic origin. Of the 145 elder siblings of Korean descent, 126 were themselves genotyped participants, while the other 19 non-genotyped elder siblings of Korean descent did not have available DNA samples.
