Alternative titles; symbols
HGNC Approved Gene Symbol: KCNJ15
Cytogenetic location: 21q22.13-q22.2 Genomic coordinates (GRCh38): 21:38,229,926-38,307,357 (from NCBI)
The potassium channel inward rectifiers (Kir) constitute a family of potassium channels that maintain the resting membrane potential close to the equilibrium potential for potassium ions.
By isolating, mapping, and sequencing trapped exons and captured cDNAs from cosmids of the Down syndrome (190685) chromosome region (DSCR) on 21q22.2, Gosset et al. (1997) discovered a gene, designated KCNJ15, encoding a member of the Kir family. The deduced protein contains 375 amino acids. Gosset et al. (1997) found that KCNJ15 is expressed in kidney and lung during human development and in several adult tissues including kidney and brain.
Okamoto et al. (2010) stated that expression of KCNJ15 in the pancreas is relatively high, as is that in the kidney, thymus, and whole blood. Immunofluorescence staining of tissue from nondiabetic patients revealed that expression of KCNJ15 in Langerhans islets of the pancreas was prominent compared to that of the exocrine glands.
Gosset et al. (1997) identified the KCNJ15 gene within the Down syndrome chromosome region on 21q22.2. Another inwardly rectifying potassium channel gene, that encoding Kir3.2 (KCNJ6; 600877), had been mapped within the DSCR.
Okamoto et al. (2010) identified a synonymous SNP in exon 4 of the KCNJ15 gene (rs3746876, C566T) that showed significant association with type 2 diabetes mellitus (T2DM; 125853) affecting lean individuals in 3 independent Japanese sample sets (p = 2.5 x 10(-7); odds ratio, 2.54) and with unstratified T2DM (p = 6.7 x 10(-6); OR, 1.76). The diabetes risk allele frequency was, however, very low among Europeans and no association between the variant and T2DM could be shown in a Danish case-control study. Functional analysis in HEK293 cells demonstrated that the risk T allele increased KCNJ15 expression via increased mRNA stability, which resulted in higher expression of protein compared to the C allele.
Gosset, P., Ghezala, G. A., Korn, B., Yaspo, M.-L., Poutska, A., Lehrach, H., Sinet, P.-M., Creau, N. A new inward rectifier potassium channel gene (KCNJ15) localized on chromosome 21 in the Down syndrome chromosome region 1 (DCR1). Genomics 44: 237-241, 1997. [PubMed: 9299242] [Full Text: https://doi.org/10.1006/geno.1997.4865]
Okamoto, K., Iwasaki, N., Nishimura, C., Doi, K., Noiri, E., Nakamura, S., Takizawa, M., Ogata, M., Fujimaki, R., Grarup, N., Pisinger, C., Borch-Johnsen, K., and 13 others. Identification of KCNJ15 as a susceptibility gene in Asian patients with type 2 diabetes mellitus. Am. J. Hum. Genet. 86: 54-64, 2010. [PubMed: 20085713] [Full Text: https://doi.org/10.1016/j.ajhg.2009.12.009]