Assignment of the catechol-O-methyltransferase gene to human chromosome 22 in somatic cell hybrids

Catechol-O-methyltransferase (COMT) plays an important role in the inactivation of catecholamines. It has been demonstrated that erythrocyte COMT activity is genetically determined and controlled by a major autosomal locus with two alleles. The recent development of a method which allows the detection of COMT isozymes directly in autoradiozymograms has provided the means to investigate the chromosome location of the gene by using somatic cell hybrids. We have found that a single form of the COMT enzyme is expressed in several mouse-human fibroblast cell lines. The data obtained from the segregation analysis of the COMT enzyme in these hybrids and their subclones have provided evidence for the location of a major gene for COMT activity on human chromosome 22.