rs80356696

A SNP in the CLCN1 gene on chromosome 7. Its most notable genotype is A;G: Myotonia congenita; Thomsen's disease; quite variable in degree

Gene
CLCN1
Location
Chr 7143,342,001 (GRCh38)
Highest magnitude
4.0Very important
Tested on
AncestryDNA

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. A;AGoodcommon in clinvarTypical · 0.0
  2. A;GMost notableBadMyotonia congenita; Thomsen's disease; quite variable in degreeVery important · 4.0

On SNPedia: (A;A), (A;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Conditions, medicines and genes

Other CLCN1 SNPs

All CLCN1 SNPs

Notes

From SNPedia

Notes

rs80356696, also known as c.1655A>G or p.Gln552Arg, is a mutation in the CLCN1 gene on chromosome 7. Acting in an autosomal dominant manner, the rs80356696(G) allele is considered to cause Thomsen's myotonia congenita; see also OMIM 118425.0007 Note that 23andMe refers to this SNP as i5003260. Myotonia levior is a chloride channel disorder. A novel alteration of muscle chloride channel gating in myotonia levior.

A;G

See discussion at myotonia congenita

Source and license

Adapted from rs80356696 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.