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rs17026688

From SNPedia

Orientationplus
Stabilizedplus
Geno Mag Summary
(C;C) 1 common
(C;T) 2
(T;T) 2
ReferenceGRCh38 38.1/141
Chromosome3
Position30845325
GeneGADL1
is asnp
is mentioned by
dbSNPrs17026688
ebirs17026688
HLIrs17026688
Exacrs17026688
Varsomers17026688
Maprs17026688
PheGenIrs17026688
hapmaprs17026688
1000 genomesrs17026688
hgdprs17026688
ensemblrs17026688
gopubmedrs17026688
geneviewrs17026688
scholarrs17026688
googlers17026688
pharmgkbrs17026688
gwascentralrs17026688
openSNPrs17026688
23andMers17026688
23andMe allrs17026688
SNP Nexus

SNPshotrs17026688
SNPdbers17026688
MSV3drs17026688
GWAS Ctlgrs17026688
GMAF0.06152
Max Magnitude2
? (C;C) (C;T) (T;T) 28
rs17026688 is a SNP located in an intron of the glutamate decarboxylase-like 1 GADL1 gene. It is linked to rs17026651, and both are 100% linked to a 1 base deletion known as 'GADL1 IVS8+48delG' (rs201973599).

In a study of ~1,700 patients of Han Chinese descent with bipolar disorder, researchers discovered that almost all of the patients who responded well to lithium treatment had at least one IVS8+48delG GADL1 allele. Initially, the researchers were focused on two nearby SNPs, rs17026688 and rs17026651, that turned out to be proxies (due to being in high linkage disequilibrium) for the deletion variant. rs17026688(T) is the "response allele", meaning that at least in these Asian patients, bipolar patients who are carriers of at least one (T) allele are predicted to respond well to lithium treatment; rs17026688(C;C) patients are predicted to respond poorly.[PMID 24369049]

The odds ratios and probabilities for this study are so high that the authors are able to calculate sensitivity, specificity, and positive and negative predictive values (PPV; NPV) for the connection between this DNA variant and being a bipolar patient who will respond well (or not) to lithium treatment. In a pooled cohort of ~400 patients, roughly divided equally between those responding well to lithium or not, the odds ratios, p values, sensitivity, specificity, PPV and NPV were around 80, 1 x 10e-50, 93%, 87%, 83% and 95%, respectively. To put it another way, while overall about half of all patients had a response allele and half didn't, only 1 in 14 patients who responded well to lithium lacked a response allele, and only 1 in 8 of those who did not respond well had a response allele. The authors naturally suggest the use of these SNPs as useful biomarkers for which patients with bipolar disorder will respond well to lithium treatment, and they also intend to (1) look for additional GADL1 gene variants acting similarly, especially in non-Asian populations given the rarity of this particular deletion variant outside of Asian population, and (2) see if these variants influence lithium treatment outcomes in other affective disorders such as major depressive disorder.[PMID 24369049]