Skip to
  1. Homepage
  2. Rare diseases
  3. Search
Simple search

Simple search

*
(*) mandatory field





 

Other search option(s)

Autosomal dominant centronuclear myopathy

Orpha number ORPHA169189
Synonym(s) AD-CNM
Prevalence Unknown
Inheritance Autosomal dominant
Age of onset Adolescent
Infancy
Childhood
ICD-10
  • G71.2
ICD-O -
OMIM
UMLS -
MeSH -
MedDRA -

Summary

Autosomal dominant centronuclear myopathy (AD-CNM) is an inherited neuromuscular disorder defined by numerous centrally placed nuclei on muscle biopsy and clinical features of a congenital myopathy. The exact prevalence remains unknown. Most commonly, the age of onset is in adolescence, although earlier presentations in infancy or childhood have been reported. Muscle weakness of variable severity is the major clinical manifestation. Distal muscle involvement, particularly in the lower limb, may precede more proximal weakness; the latter finding corresponds to a sequential pattern of involvement on muscle magnetic resonance imaging (MRI) with early involvement of the ankle plantarflexors, namely the medial gastrocnemius, followed by signal changes in the posterior and, eventually, anterior compartment of the thighs. Marked ocular involvement including ptosis and ophthalmoparesis are common, whilst contractures other than those affecting the Achilles tendon and/or long finger flexors are rare. Cardiorespiratory function has been reported as normal in most cases. Patients with early onset may improve in terms of muscle strength but may develop restrictive respiratory impairment over time. Neuropathic signs (absence of tendon reflexes on neurological examination and fibrillations or reduction of the compound muscle action potential on electrophysiological examination) may be present. Mutations in the dynamin 2 (DNM2) gene on chromosome 19p13.2 are responsible for AD-CNM. DNM2 mutations also cause Charcot-Marie-Tooth disease Type 2B (CMT2B) (see this term). Diagnosis is based on typical histopathological findings on muscle biopsy in combination with suggestive clinical features. Muscle MRI may aid the diagnosis which is confirmed on genetic testing. Genetic counseling should be offered to all patients and families. The main differential diagnoses include other congenital myopathies with predominant distal involvement, myotonic dystrophy and, if facial involvement is prominent, fascio-scapulo-humeral dystrophy (FSH) (see these terms). There is no curative treatment currently available. Management is supportive and based on a multidisciplinary approach. The disease has usually a slowly progressive course with potential loss of independent ambulation after the sixth decade.

Expert reviewer(s)

  • Dr Heinz JUNGBLUTH
  • Dr Jocelyn LAPORTE
  • Dr Carina WALLGREN-PETTERSSON

(*) Required fields.

Attention: Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.


Captcha image

Detailed information

Review article
  • EN (2008)
Guidance for genetic testing
  • EN (2012,pdf)
Get Acrobat Reader
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.