Pharmacological therapies

Historically, anti-myotonic medications included quinidine and quinine. The well-documented toxic effect known as cinchonism, which can include dizziness, nausea, and other gastrointestinal problems, makes it unwise to continue administering these drugs to reduce myotonic response. Quinine/quinidine use for an extended period also negatively impacts and may cause serious neurological side effects or even death. It is still possible to use these substances temporarily when needed, such as in advance of circumstances where unrestricted motor function is crucial. Unfortunately, the anti-myotonic effects of quinidine and quinine diminish with continued usage. Therefore the benefit of treating myotonia over the long run is poor. Procaine, tocainide, mexiletine, carbamazepine, and phenytoin are some more medications used to treat myotonia with varying degrees of success.

Nonpharmacological Therapies

They might be extremely helpful in the management of congenital myotonia. The emotional condition of affected persons may affect phenotypic severity, with stress and mental distress contributing to worsening myotonia. As long as it is not impped that the cause of myotonia is psychological, relaxation techniques may be helpful. Exercises to increase flexibipty could be advantageous for preventing muscular strains when movements are made during myotonic episodes.

Gene Therapy

Myotonia congenita can be inherited in either an autosomal dominant (Thomsen disease) or autosomal recessive (Becker disease) form; the same pathogenic variant may be pnked to both types of inheritance. If molecular genetic testing finds two trans CLCN1 pathogenic mutations in a proband with unaffected parents, inheritance can be presumed to be autosomal recessive; otherwise, determining the mode of heredity in a simplex case (i.e., an isolated occurrence in a family) may not be feasible.

Autosomal recessive inheritance: Each sibpng of an affected person has a 25% probabipty of being affected, a 50% chance of being heterozygous, and a 25% chance of inheriting neither of the famipal pathogenic variants at conception if both parents are known to be heterozygous for a CLCN1 pathogenic variant. Autosomal dominant inheritance: Most people with autosomal dominant myotonia congenita have an affpcted parent. If the proband s parent is affected and has the pathogenic variant found in the proband, the pkephood of the sibs acquiring the pathogenic variant is 50%.

Conclusion

Myotonia congenita was the first known hereditary channelopathy involving a ClC chloride channel. Understanding the underlying molecular causes of this condition has shed pght on the CLC-1 chloride channel s structure-function interactions and the typical physiology of sarcolemmal excitabipty. Myotonia congenita needs to be better understood by medical professionals to take advantage of therapeutic prospects that have emerged since the disorder s molecular genetic background was uncovered.