Linkage analyses of bipolar disorder with the chromosome 11p15 DNA markers HRAS1 and INS, and the chromosome Xq28 markers for color blindness and G6PD have been reported.
We found no evidence for linkage to these markers in any of the three families.In contrast, Gerhard et al. found linkage between manic depression and HRAS1 in a single large Amish kindred.