Myofibrillary myopathy

Classification according to ICD-10
G71.8	Other primary myopathies
ICD-10 online (WHO version 2019)

The myofibrillar myopathy (MFM) is a group of rare congenital muscular disorders . They are based on a structural defect in a protein of the muscle cell , which varies depending on the disease subtype , and which leads to the accumulation and clumping of this protein ( protein aggregate ).

Subtypes

Depending on the protein concerned, a distinction is made between the following subtypes:

Desminopathy, also known as MFM1 (affected gene: Desmin , abbreviated as DES)
αB-crystallinopathy, also referred to as MFM2 (affected gene: αB-crystallin, abbreviated to CRYAB)
Myotilinopathy , also known as MFM3 (affected gene: myotilin , abbreviated MYOT)
ZASPopathy, also known as MFM4 (affected gene: ZASP / LDB3)
Filaminopathy, also known as MFM5 (Affected gene: Filamin C or Filamin 2, abbreviated as FLNC)
BAG3opathy, also referred to as MFM6 (affected gene: BAG3)
FHL1opathy (affected gene: FHL1 )

Symptoms

Those affected suffer from muscle weakness that usually progresses slowly ( paresis ). This can - depending on the disease subtype - include both proximal (near the trunk) and distal (far away from the trunk) skeletal muscles . The heart muscle is often also affected ( cardiomyopathy ), and in some forms the respiratory muscles as well . Correspondingly, heart failure and breathing disorders can occur.

diagnosis

Electromyography (EMG) can be diagnostic of the presence of myofibrillary myopathy . In addition, increased creatine kinase values or typical changes in muscle biopsy specimens may be noticed in some cases. A reliable and exact diagnosis, including the exact subtype, is usually only made through the confirmation of a corresponding mutation in the context of a genetic analysis .

therapy

There are currently no causal therapies for these diseases. Different approaches are discussed, at which points the disease mechanism could be interfered with. The transition from promising therapeutic approaches in the laboratory to clinical trials is particularly difficult with these diseases, since a sufficiently large number of suitable study participants is required for a statistically reliable proof of effectiveness. In addition, representative data on the natural course of the disease are required as a benchmark. These aspects are difficult to cover due to the rarity of these diseases and the mostly slow and individually very different course.

Patient registry

In order to support research into therapeutic options for these rare diseases, a patient registry was established in 2017 in a cooperation between various institutes .

The aim of this register is

to better understand how many people are affected by these diseases, what ailments they have and how the disease is developing
This gives researchers both anonymized statistical data on typical symptoms / disease progression and the chance to find patients for clinical studies
To enable those affected to access clinical studies and research projects.

Web links

Myopathy, myofibrillar. In: Orphanet (Rare Disease Database).
Myofibrillar myopathy: Genetics Home Reference
Inherited Protein Aggregation Myopathies (PAM) and Myofibrillar Myopathies (MFM) patient registries

Individual evidence

^ Disease Ontology - Institute for Genome Sciences @ University of Maryland. Retrieved June 9, 2020 .
↑ Stephan Zierz: muscle disorders. 4th edition, Thieme, 2014, ISBN 978-3-13-567804-7 , p. 175.
↑ Myofibrillar myopathy | Genetic and Rare Diseases Information Center (GARD) - an NCATS Program. Retrieved June 10, 2020 .
↑ Sabrina batonnet-Pichon, Anthony Behin, Eva Cabet, Florence Delort, Patrick Vicart: myofibrillar Myopathies: New Perspectives from Animal Models to potential Therapeutic Approaches . In: Journal of Neuromuscular Diseases . tape 4 , no. 1 , ISSN 2214-3599 , p. 1–15 , doi : 10.3233 / JND-160203 , PMID 28269794 , PMC 5345645 (free full text).
↑ Quick access to the latest research for patients with myofibrillary myopathies and protein aggregate myopathies | German Society for Muscle Diseases eV (DGM). Retrieved June 9, 2020 .
↑ Background - PAM / MFM patient registry for Germany. Retrieved June 10, 2020 .

[1] Disease Ontology - Institute for Genome Sciences @ University of Maryland. Retrieved June 9, 2020 .

[2] Stephan Zierz: muscle disorders. 4th edition, Thieme, 2014, ISBN 978-3-13-567804-7 , p. 175.

[3] Myofibrillar myopathy | Genetic and Rare Diseases Information Center (GARD) - an NCATS Program. Retrieved June 10, 2020 .

[4] Sabrina batonnet-Pichon, Anthony Behin, Eva Cabet, Florence Delort, Patrick Vicart: myofibrillar Myopathies: New Perspectives from Animal Models to potential Therapeutic Approaches . In: Journal of Neuromuscular Diseases . tape 4 , no. 1 , ISSN 2214-3599 , p. 1–15 , doi : 10.3233 / JND-160203 , PMID 28269794 , PMC 5345645 (free full text).

[5] Quick access to the latest research for patients with myofibrillary myopathies and protein aggregate myopathies | German Society for Muscle Diseases eV (DGM). Retrieved June 9, 2020 .

[6] Background - PAM / MFM patient registry for Germany. Retrieved June 10, 2020 .