Duchenne muscular dystrophy
A genetically heterogeneous muscular dystrophy affecting males (predominantly) due to mutations in the encoding for the muscle fibre protein dystrophin at Xp21.2. Becker muscular dystrophy and a few other rarer myopathies are also caused by mutations of the same gene. Females can be affected by say X chromosome translocations. To complicate matters further mutations at the 12q21 region of the genome could affect myogenic factors such as MYF6 or MYF5 which might modify the presentation. Female carriers might have mild signs. As the genetics, although complex, are fairly well understood, multiple genetic therapies are in phase 1 and phase 2 trials at present.
Usually straight forward in males:
- Gait difficulty beginning at age three
- Progressive myopathic weakness
- Pseudohypertrophy of calves
- Possibly learning difficulties
- Very high serum level creatine kinase
- Muscle biopsy(take care as histology has to be interpreted in clinical context)
- High dose deflazacort is licensed in some jurisdictions and there is some evidence that different corticosteroids have slightly different side effect profiles. The optimum regime for prednisone or prednisolone is yet to be determined but the benefit is probably a class effect.
- Ciclosporin A does not work.
- Eteplirsen may work in some.
- ↑ Griggs RC, Miller JP, Greenberg CR, Fehlings DL, Pestronk A, Mendell JR, Moxley RT, King W, Kissel JT, Cwik V, Vanasse M, Florence JM, Pandya S, Dubow JS, Meyer JM. Efficacy and safety of deflazacort vs prednisone and placebo for Duchenne muscular dystrophy. Neurology. 2016 Aug 26.(Epub ahead of print) (Link to article – subscription may be required.)
- ↑ Sienko S, Buckon C, Fowler E, Bagley A, Staudt L, Sison-Williamson M, Zebracki K, McDonald CM, Sussman M. Prednisone and Deflazacort in Duchenne Muscular Dystrophy: Do They Play a Different Role in Child Behavior and Perceived Quality of Life? PLoS currents. 2016; 8:.(Epub) (Link to article – subscription may be required.)
- ↑ Matthews E, Brassington R, Kuntzer T, Jichi F, Manzur AY. Corticosteroids for the treatment of Duchenne muscular dystrophy. The Cochrane database of systematic reviews. 2016; (5):CD003725.(Epub) (Link to article – subscription may be required.)
- ↑ Kirschner J, Schessl J, Schara U, Reitter B, Stettner GM, Hobbiebrunken E, Wilichowski E, Bernert G, Weiss S, Stehling F, Wiegand G, Müller-Felber W, Thiele S, Grieben U, von der Hagen M, Lütschg J, Schmoor C, Ihorst G, Korinthenberg R. Treatment of Duchenne muscular dystrophy with ciclosporin A: a randomised, double-blind, placebo-controlled multicentre trial. Lancet neurology. 2010 Aug 26.(Epub ahead of print) (Link to article – subscription may be required.)
- ↑ Nigro G. One-hundred-seventy-five years of Neapolitan contributions to the fight against the muscular diseases. Acta myologica : myopathies and cardiomyopathies : official journal of the Mediterranean Society of Myology / edited by the Gaetano Conte Academy for the study of striated muscle diseases. 2010 Dec; 29(3):369-91.
- ↑ Duchenne. The Pathology of Paralysis with Muscular Degeneration (Paralysie Myosclerotique), or Paralysis with Apparent Hypertrophy. British medical journal. 1867 Dec 14; 2(363):541-2.