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Genetic and Rare Diseases Information Center (GARD)

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Trabecular myopathy


Other Names for this Disease

  • Myopathy with lobulated fibers
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Your Question

I have been diagnosed with trabecular fiber myopathy and can find nothing about it. I would like any information you can give me.

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is trabecular myopathy?

Trabecular myopathy is a term that has been used to describe a disorder with symptoms resembling limb-girdle muscular dystrophy, in which the main feature on muscle biopsy is an abundance of trabecular muscle fibers. Signs and symptoms reported include slowly progressive muscle weakness of the upper arms and upper legs; and possible weakness of neck, respiratory, or bulbar muscles (those used for speech and swallowing).[1] The condition typically begins in adulthood and occurs in both males and females. Most affected people do not have a family history suggestive of muscle disease.[2][1]
Last updated: 9/24/2014

What causes trabecular myopathy?

The term "trabecular myopathy" has been used to describe cases of muscle disease in which at least 20% of muscle fibers have trabecular changes on muscle biopsy.[2] Trabecular (also called lobulated) fibers are characterized by abnormal distribution of mitochondria, the energy producing centers within cells. In these abnormal fibers, mitochondria cluster together in some areas and are absent in other areas. Researchers propose that this abnormal distribution of mitochondria results in uneven amounts of energy within the muscle cells, which could lead to abnormal muscle structure and function.[2] The exact, underlying reason that the trabecular or lobulated fibers occur has not yet been identified.

In a 2002 study by D. Figarella-Branger et. al in which 17 people with trabecular myopathy had molecular and genetic testing, it was reported that there were different underlying genetic causes for the disorder among some patients. For example, based on the testing, two patients were found to have facioscapulohumeral muscular dystrophy; one had a sarcoglycanopathy (a type of limb-girdle muscular dystrophy); and another had a family history of Duchenne muscular dystrophy (DMD) and was a DMD carrier. A couple of patients were strongly believed to have a calpainopathy (limb-girdle muscular dystrophy type 2A).[3]

The authors of the study reported that the underlying genetic cause of the condition remains unknown in 60% of cases.[3]
Last updated: 9/24/2014

References
  • Irodenko VS, Lee HS, de Armond SJ, Layzer RB.. Adult nemaline myopathy with trabecular muscle fibers. Muscle Nerve. June, 2009; 39(6):871-875. Accessed 9/24/2014.
  • Weller B, Carpenter S, Lochmuller H, Karpati G. Myopathy with trabecular muscle fibers. Neuromuscular Disorders. 1999;
  • Figarella-Branger D, et. al. Myopathy with lobulated muscle fibers: evidence for heterogeneous etiology and clinical presentation. Neuromuscul Disord. January, 2002; 12(1):4-12. Accessed 9/24/2014.
  • Figarella-Branger D, El-Dassouki M, Saenz A, Cobo AM, Malzac P, Tong S, Cassotte E, Azulay JP, Pouget J, Pellissier JF. Myopathy with lobulated muscle fibers: evidence for heterogeneous etiology and clinical presentation. Neuromuscular Disorders. 2002; 12(1):4-12.
Other Names for this Disease
  • Myopathy with lobulated fibers
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.