Limb girdle dystrophy 1B

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Classification according to ICD-10
G71.0 Muscular dystrophy
- pelvic or shoulder girdle shape
ICD-10 online (WHO version 2019)

The limb-1B (LGMD1B) is a very rare disease from the group of limb-girdle muscular dystrophy .

root cause

The LGMD1B is caused by mutations in the LMNA gene in humans (chromosome 1 1q22) gives and autosomal - dominant inherited. LMNA codes for the protein Lamin A / C , which is a homodimer of Lamin A and Lamin C and is part of the nuclear lamina . The protein Lamin A / C is assigned numerous functions, including an important role in the organization of chromatin . More than 30 mutations in the LMNA gene are known that lead to the LGMD1B phenotype. Mutations in the LMNA gene can, however, also lead to numerous other diseases or phenotypes, which are collectively referred to as laminopathies , e.g. B. mandibuloacral dysplasia .

Clinical picture

The age of manifestation of LGMD1B is usually less than 20 years. The disease begins with symmetrical, proximal muscle weakness of the lower extremities. The muscles of the upper extremities are usually only affected in the third to fourth decade of life. Heart involvement is possible and, in addition to atrioventricular conduction disorders, can lead to syncope and sudden cardiac death .

Diagnosis

The creatine kinase in the blood serum is usually normal. In electromyography nonspecific are myopathic changes detectable. Even in the histological examination of muscle biopsies , only very mild myopathic changes are usually detectable. Lamin-A / C-positive aggregates can be detected immunohistochemically. The diagnosis can only be confirmed by means of molecular genetic testing.

literature

  • M. Puckelwartz, EM McNally: Emery-Dreifuss Muscular Dystrophy . In: Robert Griggs: Muscular Dystrophies , Handbook of Clinical Neurology, Volume 101, 3rd Edition, Elsevier, May 24, 2011, ISBN 978-0-08045-031-5 , pp. 159-160.
  • L. Broglio, M. Tentorio, et al. a .: Limb-girdle muscular dystrophy-associated protein diseases. In: The neurologist. Volume 16, Number 6, November 2010, pp. 340-352, ISSN  1074-7931 . doi : 10.1097 / NRL.0b013e3181d35b39 . PMID 21150381 . (Review).

Web links

Individual evidence

  1. ↑ Lamin A / C.  In: Online Mendelian Inheritance in Man . (English)
  2. ↑ UniProt P02545