myofibrillar myopathy 11

Myofibrillar Myopathy-11 (MFM11) is a rare and autosomal recessive skeletal muscle disorder characterized by slowly progressive proximal muscle weakness starting in childhood or adolescence [2]. The onset of symptoms can vary, but it typically begins with weakness in the muscles closest to the trunk of the body, such as those in the shoulders, hips, and thighs [3].

This condition is part of a group of disorders known as muscular dystrophies, which affect muscle function and cause weakness [6]. Myofibrillar myopathies, including MFM11, are characterized by the degeneration of muscle fibers at the ultrastructural level, specifically the disintegration of sarcomeric Z-disks [1].

Symptoms of MFM11 can include:

• Slowly progressive proximal muscle weakness
• Muscle wasting and atrophy
• Difficulty with activities that require muscle strength, such as walking or climbing stairs

It's essential to note that myofibrillar myopathies are a clinically and genetically heterogeneous group of neuromuscular disorders [7]. This means that the symptoms and progression of MFM11 can vary significantly from person to person.

References: [1] - Context result 1 [2] - Context result 2 [3] - Context result 5 [6] - Context result 6 [7] - Context result 7

Myofibrillar Myopathy (MFM) is a rare genetic disorder that affects the muscles. The signs and symptoms of MFM can vary from person to person, but here are some common ones:

• Muscle weakness: This is one of the most common symptoms of MFM, and it can affect any muscle group in the body.
• Cardiomyopathy: A weakened heart muscle that can lead to heart failure.
• Muscle pain (myalgia): Pain or tenderness in the muscles, which can be severe in some cases.
• Loss of sensation: Numbness or tingling sensations in the limbs, which can be due to peripheral neuropathy.

It's worth noting that these symptoms are not specific to MFM and can occur with other conditions. A proper diagnosis by a healthcare professional is necessary for an accurate diagnosis.

References: [1] - These conditions are highly variable but are characterized by a slowly progressive muscle weakness that can involve skeletal muscle (muscles ...)[2] - Other signs and symptoms of myofibrillar myopathy can include a weakened heart muscle (cardiomyopathy), muscle pain (myalgia), loss of ... [3] - Other symptoms that can be associated with MFM include pain and tingling in the limbs (peripheral neuropathy) or an enlarged and weakened heart (cardiomyopathy) ...

Diagnostic Tests for Myofibrillar Myopathy

Myofibrillar myopathy can be diagnosed using various diagnostic tests, which are essential in confirming the condition. The following tests are commonly used:

• Electrodiagnostic testing: This is the core diagnostic modality for patients with a suspected myopathy. It comprises nerve conduction studies (NCS) and electromyography (EMG). These tests help evaluate muscle function and detect any abnormalities.
• Muscle biopsy: A muscle biopsy can be used to confirm the diagnosis of myofibrillar myopathy. The biopsy involves taking a sample of muscle tissue, which is then examined under a microscope for any signs of abnormality.
• Molecular genetic testing: This test can help identify the specific gene mutation responsible for the condition. Genetic testing for mutations in the DES, CRYAB, MYOT, ZASP, BAG3, DNAJB6, TTN, and FLNC genes is available to confirm the diagnosis.

These diagnostic tests are essential in confirming the diagnosis of myofibrillar myopathy and can help guide treatment decisions. [11][12][14]

Current Status of Drug Treatment for Myofibrillar Myopathy

Unfortunately, there is no effective treatment available for myofibrillar myopathy at present [4][9]. The high cost of treatment poses significant burdens for patients, their families, and the healthcare system [4].

However, researchers are exploring potential therapeutic options. For instance, a study found that metformin, a drug typically used to treat diabetes, can remove accumulating damaged protein in fish models of myofibrillar myopathy [7]. Another study demonstrated that metformin reduces protein aggregation and prevents fiber disintegration in a similar model [8].

Additionally, a new drug has been developed using effective components of the Chinese herbal medicine Chaenomelis Fructus for the treatment of this rare disease [5]. However, more research is needed to confirm its efficacy and safety.

Potential Therapeutic Options

• Metformin: A study suggests that metformin may be beneficial in removing damaged protein accumulation in myofibrillar myopathy models.
• Chaenomelis Fructus-based drug: A new drug has been developed using components of this Chinese herbal medicine for the treatment of myofibrillar myopathy.

Limitations and Future Directions

While these findings are promising, it is essential to note that more research is required to confirm the efficacy and safety of these potential therapeutic options. Furthermore, the high cost of treatment remains a significant challenge in managing myofibrillar myopathy.

References: [4] Jan 10, 2024 — Currently, there is no effective treatment for myofibrillar myopathy, and the high cost of treatment poses significant burdens for patients, ... [7] Oct 14, 2020 — We found that one of the drugs, metformin, which is normally used to treat diabetes, removed the accumulating damaged protein in the fish, ... [8] by AA Ruparelia · 2021 · Cited by 36 — Our data collectively demonstrated that the FDA-approved, autophagy stimulating drug, metformin reduced protein aggregation, prevented fiber disintegration, ... [9] Jan 12, 2024 — has developed a new drug using effective components of a Chinese herbal medicine, Chaenomelis Fructus, for the treatment of the rare disease, ...

The differential diagnosis for myofibrillar myopathy (MFM) includes several conditions that can present with similar symptoms and muscle biopsy findings.

• Myotonic dystrophy: This is a genetic disorder characterized by progressive muscle stiffness, wasting, and weakness. It is often associated with cataracts, heart conduction defects, and endocrine problems [6].
• Other muscular dystrophies: MFM can be distinguished from other muscular dystrophies such as Duchenne and Becker muscular dystrophy, which are caused by mutations in the dystrophin gene [4].
• Motor and sensory neuropathies: These conditions can present with muscle weakness, wasting, and sensory deficits, but they typically do not involve the characteristic rimmed vacuoles seen in MFM [6].

A diagnosis of MFM is made based on a combination of clinical findings, electromyography (EMG), nerve conduction studies (NCS), and muscle biopsy. Molecular genetic testing for the DES, CRYAB, MYOT genes can also be performed to confirm the diagnosis [7].