A YAC Contig Spanning a Cluster of Human Type III Receptor Protein Tyrosine Kinase Genes (PDGFRA-KIT-KDR) in Chromosome Segment 4q12

Abstract We have mapped five genes encoding protein tyrosine kinases (PTKs) to the pericentromeric region of human chromosome 4. PTK4 and TYRO4 , which encode nonreceptor intracellular PTKs, are located at 4p12 and 4q13, respectively. The other three genes, PDGFRA, KIT , and KDR , encode type III transmembrane receptor PTKs for known ligands. We have developed a contig of 29 yeast artificial chromosomes (YACs) spanning approximately 2 Mb of DNA at 4q12 that includes PDGFRA, KIT , and KDR , and we have used this YAC contig to map 12 different sequence-tagged sites in this region. PDGFRA, KIT , and KDR thus constitute a cluster of genes at 4q12 encoding closely related type III receptor PTKs. Mutations of the human KIT gene result in piebaldism, an autosomal dominant disorder of melanocyte development.