Evidence for X-Linkage in the Transmission of Manic-Depressive Illness

Seven families were found in which manic-depressive illness and either protan or deutan color blindness (X-linked recessive traits) occurred in successive generations. In these seven families, as well as in two others previously reported in the literature, detailed analysis suggests that the genetic loci for manic-depressive illness and the two kinds of colorblindness may be located on the same chromosome. A dominant X-linked gene may thus be involved in the pathogenesis of manic-depressive illness.