rs28930069

A SNP in the CACNA1S gene on chromosome 1. Its most notable genotype is C;G: Malignant Hyperthermia susceptibility

Gene
CACNA1S
Location
Chr 1201,053,539 (GRCh38)
Highest magnitude
6.6Very important
Tested on
23andMe, AncestryDNA

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GGoodcommon in clinvarTypical · 0.0
  2. C;GMost notableBadMalignant Hyperthermia susceptibilityVery important · 6.6
  3. C;CBadHypokalemic periodic paralysis riskVery important · 5.0

SNPedia records rs28930069 on the minus strand: (C;C), (C;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Conditions, medicines and genes

Other CACNA1S SNPs

All CACNA1S SNPs

Notes

From SNPedia

Notes

rs28930069, also known as R1239G or Arg1239Gly, is a SNP in the CACNA1S gene on chromosome 1. The rs28930069(G) allele has been reported in a family study to be the basis for their hypokalemic periodic paralysis, type 1. This variant meets the criteria published in 2013 by the ACMG regarding incidental findings in exome or genome sequencing, as a variant that they do recommend informing a patient about.

C;C

Assuming the orientation hasn't been flipped, this (G;G) genotype is associated with significant risk for hypokalemic periodic paralysis; see discussion at rs28930069. However, be wary of the ambiguous flip issue that may cause confusion for this SNP between (C;C) and (G;G) genotypes.

Source and license

Adapted from rs28930069 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.

SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.