Rs80356690

rs80356690 is a mutation in the CLCN1 gene on chromosome 7.

Acting in an autosomal dominant manner, the rs80356690(G) allele is considered to cause Thomsen's myotonia congenita; see also OMIM 118425.0008

Note that 23andMe refers to this SNP as i5003259. Myotonia levior is a chloride channel disorder.