Macrorestriction mapping of COL4A1 and COL4A2 collagen genes on human chromosome 13q34.

The genes for the alpha-1 and alpha-2 chains of type IV collagen (COL4A1 and COL4A2) map to the same chromosomal band (13q34) and have a high degree of nucleotide homology. We have used pulsed field gel electrophoresis and cloned COL4A1 and COL4A2 DNA fragments as molecular probes to construct a 1200-kb macrorestriction map which encompasses both genes. The two genes are located within a 340-kb region with the 3' end of COL4A2 and the 5' region of COL4A1 separated by at least 100 kb but not more than 160 kb. These genes, therefore, are two members of a gene cluster on chromosome 13q34.