Bipolar disorder is a highly heritable disease, which has been proven by many family, twin and adoption studies, as well as modern genetic approaches. A long list of possible susceptibility genes has been discovered so far (see page 21). Interestingly top candidates belong to the Ion channel group and Ion channel associated proteins- especially ANK3 and CACNA1C are favorite predisposing genes. CACNA1C codes for the alpha1C subunit of the L-type voltage-gated calcium channel and influences verbal fluency aside from other important func- tions. ANK3 codes for an adaptor protein, which regulates the assembly of vol- tage-gated sodium channels at axon initial segments. Until now both genes show genome wide significant evidence of association with bipolar disorder. Another promising chapter of bipolar disorder research is the growth hormone group. BDNF seems to be associated with bipolar disorder in Caucasians, but not in Asians. BDNF could even be a laboratory marker for bipolar disorder because serum levels are decreased in manic, depressed and euthymic states of manic- depressive disease. BDNF is responsible for neuronal development, synapse formation, serotonergic axon growth, memory acquisition and consolidation, and antidepressant effect, therefore a role in pathogenesis of bipolar disorder is not unlikely. A further candidate gene group includes the “clock genes”, including ARNTL, CRY1 and 2, PER1-3. Changes in circadian rhythms are typical fea- tures in mood disorders. This goes along with the positive study results for many “clock gene” polymorphisms in smaller association studies, but not in recent GWAS. Although everybody would expect the serotonin...
You are not authenticated to view the full text of this chapter or article.
This site requires a subscription or purchase to access the full text of books or journals.
Do you have any questions? Contact us.Or login to access all content.