Rs80356699

rs80356699 is a mutation in the CLCN1 gene on chromosome 7.

Acting in an autosomal dominant manner, the rs80356699(G) allele is considered to cause Thomsen's myotonia congenita; see also OMIM 118425.0016

Note that 23andMe refers to this SNP as i5003254. Decrement of compound muscle action potential is related to mutation type in myotonia congenita.