Interestingly, Mbnl1−/−; ClC-1ΔE7a/+ mice with only a single allele with forced E7a exclusion, also lacked any evidence of myotonia, and thus for all physiologic experiments both heterozygote and homozygote ClC-1ΔE7a mice were used as indicated by either ClC-1ΔE7a or Mbnl1−/−; ClC-1ΔE7a. The gene discussed is MBNL1; the disease is Myotonia.