Fig. 1. Chromosomal locations of mammalian LBH loci. The positions of mouse Lbh on chromosome 17E2 and human LBH on chromosome 2p23.3 are shown relative to linkage markers and neighboring genes within the same syntenic region. The scheme shows a physical linkage map of mouse chromosome 17 (in centiMorgans; cM), whereas the map of human chromosomal region 2p23-21 represents the actual gene sequence on the chromosome 2 contingent in 100 kilobase (kb) increments. Mouse Lbh maps either proximally or distally of linkage marker D17Mit92 with a LOD score of 20.0. Bars indicate chromosomal segments triplicated in individuals with partial trisomy 2p syndrome with CHD (reviewed by Lurie et al., 1995).