A microsatellite linkage scan was conducted on a sample of 2,282 individuals from 262 families densely affected with alcohol dependence [Reich et al., 1998; Foroud et al., 2000]. Genotyping for the microsatellite linkage scan was carried out in laboratories at Indiana University and Washington University in St. Louis using radioactive and fluorescence-based detection systems, as described previously [Reich et al., 1998; Foroud et al., 2000]. The current analyses are based on a map of 315 autosomal microsatellite markers with an average intermarker distance of 11.5 cM. Pedigrees were checked for non-Mendelian inheritance using the GeneMaster database and the programs CRIMAP [Green, 1990] and USERM13 [Boehnke, 1991]. Recombination-based marker maps were generated from the sample using CRIMAP. Maximum likelihood estimates of marker allele frequencies were computed from the data using USERM13. The majority of the sample (84%) was Caucasian; 13% was African American, and <3% reported mixed or other ethnicities. Alleles were coded separately for Caucasians and African Americans/others to take into account allele frequency differences between the populations.
