IMPA1

inositol monophosphatase 1

Summary

This gene encodes an enzyme that dephosphorylates myo-inositol monophosphate to generate free myo-inositol, a precursor of phosphatidylinositol, and is therefore an important modulator of intracellular signal transduction via the production of the second messengers myoinositol 1,4,5-trisphosphate and diacylglycerol. This enzyme can also use myo-inositol-1,3-diphosphate, myo-inositol-1,4-diphosphate, scyllo-inositol-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-phosphate, beta-glycerophosphate, and 2'-AMP as substrates. This enzyme shows magnesium-dependent phosphatase activity and is inhibited by therapeutic concentrations of lithium. Inhibition of inositol monophosphate hydroylosis and subsequent depletion of inositol for phosphatidylinositol synthesis may explain the anti-manic and anti-depressive effects of lithium administered to treat bipolar disorder. Alternative splicing results in multiple transcript variants encoding distinct isoforms. A pseudogene of this gene is also present on chromosome 8q21.13. [provided by RefSeq, Dec 2014]

Known Variants25 total

rsidPosition (GRCh37)AllelesClassClinVar
rs13083257078:82,571,603G/Alikely pathogenic
rs12776010018:82,571,612G/Auncertain significance
rs3749852148:82,571,633C/Tuncertain significance
rs7782708928:82,571,636T/Cuncertain significance
rs12602615538:82,571,701C/Tuncertain significance
rs7754770388:82,572,784T/Auncertain significance
rs5628725438:82,572,850C/Tuncertain significance
rs1498241658:82,572,856T/Cuncertain significance
rs24005898:82,575,783C/Tintron variant
rs7483927928:82,583,204A/Guncertain significance
rs24877577448:82,583,243G/Auncertain significance
rs617345128:82,583,280T/Cuncertain significance
rs3767424718:82,586,154C/Guncertain significance
rs12502818878:82,586,156A/Guncertain significance
rs1837720978:82,588,523A/Tbenign
rs1395552248:82,591,417G/Tlikely benign
rs617557418:82,592,945G/Auncertain significance
rs617557408:82,592,967G/Alikely benign
rs5552504398:82,592,972C/Tuncertain significance
rs5747303028:82,592,987T/Cuncertain significance
rs10391102618:82,593,737C/Tuncertain significance
rs1428757608:82,598,063T/Cbenign
rs18075053848:82,598,098A/Guncertain significance
rs11874276948:82,598,138G/Tuncertain significance
rs18075080378:82,598,142C/Guncertain significance

Gene information from NCBI Gene. Variant classifications from ClinVar.