Bipolar disorder is a psychiatric disorder characterized by recurrent large mood swings; it has also been referred to as manic-depressive illness. An article in Wikipedia provides further general details. The heritability of bipolar disorder is around 70% [PMID 14601036].
A deletion variant, 'GADL1 IVS8+48delG' (rs201973599), and two SNPs tightly linked to it, rs17026688 and rs17026651, have been found in Asian patients (of Han Chinese descent) with bipolar disorder to be quite predictive of responding well to lithium treatment.[PMID 24369049]
SNPs in quite a few genes have been associated with increased risk for bipolar disorder, although most are calculated to be of low effect individually and few are seen to be replicated in diverse populations. Some of the reported SNPs include:
- An increase in GSK3B gene CNVs [PMID 17357145]
- Two SNPs in the TPH2 gene: rs11178997 and rs17110563
- Several SNPs in the BDNF gene [PMID 19018231]
- rs1006737, risk allele A [PMID 18711365]
- rs2159100, risk allele T
- One SNP in the ESR1 gene: rs2144025, risk allele T [PMID 28617822]
A quite large 2007 study revealed numerous SNPs, though generally each has relatively low effects on its own; these include [PMID 17554300]:
Somewhat apart from all these studies, SNPs in the GRK3 gene are said to be implicated in at least some bipolar disorder patients; see the GRK3 gene entry for more information.
[PMID 19488044] reports that SNPs contributing to bipolar disorder may vary between individuals of European ancestry compared to African ancestry.