Bone morphogenetic proteins (BMP) are the only known biologic factors capable of inducing endochondral ossification at an extraskeletal site. Seven members of the BMP family have been identified thus far and are involved in osteoinduction and morphogenesis. The authors established the chromosomal assignment of the gene for BMP4 on human chromosome 14 by using somatic cell hybrid panels and molecular technology. The genetic map of chromosome 14 shows that Holt-Oram Syndrome (HOS), a heritable disorder of skeletal and cardiac development, may be located also on chromosome 14. Linkage analysis studies in large families with HOS will determine if the BMP4 gene is related to HOS. In addition, analysis shows that the BMP4 gene maps to a conserved region of the mouse and human genomes. The chromosomal locus of a gene is part of human anatomy and provides a genomic landmark for studies on the pathogenesis of heritable disorders.