The subproject on the genetics of familial combined hyperlipidemia (FCHL) was renewed in 1999 through 2010 to continue mapping the apoB elevating gene l(BEL) level using a genomic search in pedigrees with familial combined hyperlipidemia. The major focus of the genetic analyses are the 15 FCHL families under the BEL segregation analysis model in a power analysis. These families also show the most evidence for segregation at an apoB elevating gene locus. Genotyping for a 10 centimorgan genomic scan has been completed for these families.