The paper presents preliminary results of linkage relations of the locus for granular corneal dystrophy Groenouw type I employing 35 classic genetic markers. Blood and saliva from 124 members of one family with this disorder were examined with the aim of localizing the disease to a certain chromosome. The highest lodscore was 1.04 in females at theta 0.00 to the system C1R, thus supplying a clue for continued gene-mapping investigations on the short arm of chromosome No. 12.