Congenital Muscular Dystrophies (CMD)

This is a group of muscular dystrophies that have the common feature of muscle weakness that begins at infancy or early childhood (before the first 2 years). It concerns both boys and girls and is often perceived when the child fails to grow as expected. Most CMDs are inherited in an autosomal recessive and rarely in an autosomal dominant pattern.

 

Symptoms

Generally, in babies the first symptoms are inadequate control of head support and movement, slow motion, lack of coordination, hypotonic muscles and possible hip dislocations. In addition, there may be breathing and swallowing problems. Often, babies show muscular tenderness in elbows, hips, knees or ankles and may experience scoliosis.

 

The main CMD categories and some representative symptoms are:

 

Laminin-deficient CMD 2 –Need of support in sitting or upright positioning, neuropathy, epilepsy (30% of cases), cardiomyopathy.

CMD with partial deficiency of laminin 2 – Rarely – limb girdle weakness, muscle hypertrophy, (possible) respiratory failure.

Protein related to Fuculin proteins – Similar to the first category.

CMD related to LARGE protein – Similarities with Muscle-Eye-Encephalopathy and Walker-Warburg syndrome, mental retardation.

Fukuyama CMD – Mental deprivation, epilepsy, gait, similarities with muscle-eye-encephalopathy (common in Japan).

Muscle – eye – encephalopathy – Severe muscle weakness, mental retardation, headache with anterior forehead, severe eye problems, limited mobility due to contractures.

Walker-Warburg’s Syndrome – Fatal in early life due to serious damage to the central nervous system.

Ullrich CMD and Bethlem myopathy – Hyperactivity, eventual motion problems or in severe Ullrich cases complete inability to walk.

Integrin α7 Problem – Very rare – very late onset of walking and movement (after 2-3 years of life).

 

Muscular Dystrophy with spine stiffness – Late gait, breathing problems, spinal rigidity, muscle weakness.

CMD laminin related A / C – Backbone spasticity, limited mobility, weakness and “fallen head” syndrome.

 

Diagnosis

Diagnosis is based on a variety of media due to different types and inheritance. A family history and clinical examination is performed to detect outbreaks within the family and clinical findings respectively. Blood tests to determine the CK enzyme, indicating muscle cell destruction, electromyography and muscle biopsy to detect muscle cell damage and genetic testing.

 

Progression – Management

The progression of the disease varies according to the type of CMD. Some children with CMD die at neonatal age, while other patients live as adults with a minor disability.

There is no cure for CMD, but there are ways and means of managing the symptoms, such as physiotherapy and appropriate stretching exercises to reduce contractures and the likelihood of scoliosis. Orthopaedic interventions are rarely performed to treat complications. There are assistive devices and media facilitating movement and promoting patient independence, e.g. trolleys. For those experiencing seizures, the necessary medication is followed and when ingestion problems occur, a suitable feeding tube is placed.

For more details, visit the guidelines from the American Academy of Neurology.

 

Information about clinical trials conducted globally: https://www.centerwatch.com/clinical-trials/listings/condition/350/muscular-dystrophy/ and https://clinicaltrials.gov/ct2/home

References

  • C.H. Wang, et al, Consensus statement on standard of care for congenital muscular dystrophy, J. Child Neurol., 2010, 25, 10, pp. 1559-1581.
  • CureCMD, https://www.curecmd.org/collagen-vi-ullrich-bethlem
  • E. Bertini, et al, Congenital muscular dystrophy: a brief review, Semin. Pediatr., Neurol., 2011, 18, pp. 277-288.
  • Genetics Home Reference – Walker-Warburg syndrome, https://ghr.nlm.nih.gov/condition/walker-warburg-syndrome. 
  • G.J Jobsis, J.M. Boers, P.G. Barth, M. de Visser , Bethlem myopathy: a slowly progressive congenital muscular dystrophy with contractures, Brain, 1999, 122, pp. 649-655, https://watermark.silverchair.com/1220649.pdf
  • J. Finsterer, et al, Cardiac findings in congenital muscular dystrophies, Pediatrics, 2010, 126, 3, pp. 538-545.
  • L. Maggi, N. Carboni, P. Bernasconi, Skeletal muscle laminopathies: a review of clinical and molecular features, Cells, 2016, 33, 5.
  • Muscular Dystrophy Canada, Congenital Muscular Dystrophy, Standards of Care, http://muscle.ca/wp-content/uploads/2012/11/Standards-of-Care-CMD.pd
  • Muscular Dystrophy Association, About Neuromuscular Diseases, June 08, 2017, https://www.mda.org/disease/
  • NORD (National Organization for Rare Disorders), Rare diseases, https://rarediseases.org/rare-diseases/
  • P.B. Kang et al, Evidence-based guideline summary: Evaluation, diagnosis, and management of congenital muscular dystrophy, Neurology, 2015, 84, pp. 1369-1379.
  • R. Falsaperla et al, Congenital muscular dystrophy: from muscle to brain, Ital. J. Pediatr., 2016, 42, pp. 78-88.
  • Van Munster et al, The rigid spine syndrome, J. Neurol. Neurosurg. Psychiatry, 1986, 49, pp. 1292-1297, https://jnnp.bmj.com/content/jnnp/49/11/1292.full.pdf. 
  • X.N. Fu, H. Xiong, Genetic and clinical advances of congenital muscular dystrophy, Chinese Med. J., 2017, 130, 21, pp. 2624-2631.

 

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