Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2025 May 18;17(5):e84373.
doi: 10.7759/cureus.84373. eCollection 2025 May.

Autosomal Recessive Becker's Form of Myotonia Congenita in Indian Families

Sahithi Krovvidi  1 , Srilaxmi Nelakurthi  2 , Mounika Gedela  2 , Srinithya Singamsetty  2 , Vijayalakshmi Bhimireddy  2
Affiliations
Case Reports

Autosomal Recessive Becker's Form of Myotonia Congenita in Indian Families

Sahithi Krovvidi et al. Cureus. .

Abstract

Myotonia congenita (MC), a rare inherited disease, is caused by variations in the skeletal muscle chloride voltage-gated channel one gene (CLCN1) and is characterized by symptoms of myotonia and muscle hypertrophy. We present a case report of two female patients aged nine and 10, from Andhra Pradesh, India, with a history of parental consanguinity, hypertrophy of arm and calf muscles, permanent weakness, and proximal muscle weakness. Patients were diagnosed with Becker's form of MC after genetic testing that reported the mutation c.1667T >A (p.lle556Asn) in exon 15 of the CLCN1, which is a pathogenic variant. Treatment with mexiletine showed improvement in the condition of patients. Because of its inherent nature, parents were given genetic counseling and the choice of antenatal diagnosis for upcoming pregnancies.

Keywords: becker’s disease; clcn1 gene; mutation; myotonia congenita; non-dystrophic myotonia.

PubMed Disclaimer

Conflict of interest statement

Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Institutional Ethics Committee of NRI Medical College and General Hospital issued approval IEC2025 Case Report 03/CK. The Institutional Ethical Committee waived the approval as no clinical trial or experimentation was conducted. Written consent of the participant persons was obtained. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Pedigree of the proband
The arrow indicates the female proband
Figure 2
Figure 2. Hypertrophy of shoulder muscles (case 1)
Bodybuilder appearance due to prominent shoulder girdle muscles indicative of Becker’s form of MC MC: Myotonia congenita
Figure 3
Figure 3. Hypertrophy of calf muscles (case 2)
Figure showing the prominent calf muscle hypertrophy
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Transient weakness and altered membrane characteristic in recessive generalized myotonia (Becker) Rüdel R, Ricker K, Lehmann-Horn F. Muscle Nerve. 1988;11:202–211. - PubMed
    1. Myotonia congenita. Gutmann L, Phillips LH 2nd. Semin Neurol. 1991;11:244–248. - PubMed
    1. Chapter 2 myotonia congenita. Lossin C, George AL Jr. Adv Genet. 2008;63:25–55. - PubMed
    1. Novel mutations in the muscle chloride channel CLCN1 gene causing myotonia congenita in Spanish families. de Diego C, Gámez J, Plassart-Schiess E, et al. J Neurol. 1999;246:825–829. - PubMed
    1. A population-based epidemiologic study of adult neuromuscular disease in the Republic of Ireland. Lefter S, Hardiman O, Ryan AM. Neurology. 2017;88:304–313. - PubMed

Publication types

LinkOut - more resources