Linkage analysis of serum MCP-1. Age- and sex-adjusted multipoint linkage of MCP-1 on chromosome 1 (154.8 Mb) with an LOD score of 14.3; genome-wide P = 8.0 * 10−13. The DARC gene is located between 157 441 134 and 157 442 914 base pairs (bp) on chromosome 1.