CLONING OF MITF, THE HUMAN HOMOLOG OF THE MOUSE MICROPHTHALMIA GENE AND ASSIGNMENT TO CHROMOSOME 3P14.1 - P12.3

The mouse microphthalmia (mi) gene encodes a basic - helix - loop - he lix - zipper protein whose mutations may lead to loss of pigmentation in the eye, inner ear and skin, and to reduced eye size and early onse t deafness. Mice with mutations at mi serve as models for human pigmen t disturbances in skin and eye that may be combined with sensorineural deafness. We have now obtained cDNA and genomic clones of the human h omolog of mouse mi, identified a restriction fragment length polymorph ism in the gene, and mapped the gene by somatic cell hybrid and fluore scence in situ hybridization techniques to a region of human chromosom e 3 that shows a disrupted syntenic conservation with the region on mo use chromosome 6 to which mi maps. These studies will help to verify i f any of the hereditary pigment disturbances in humans are due to muta tions in this gene.