congenital myopathy 16

What is Congenital Myopathy?

Congenital myopathy is a rare inherited disorder that causes lack of muscle tone and muscle weakness in an individual, typically present at birth [1]. It is characterized by hypotonia (low muscle tone) and weakness, usually present from birth, with a static or slowly progressive clinical course [4].

Types of Congenital Myopathies

There are several different types of congenital myopathy, each caused by a genetic change (mutation) in one of several genes [1]. These disorders cause weakness in the muscles throughout the body and often start before birth or in infancy, though milder forms may start later [3].

Symptoms of Congenital Myopathy

Infants with congenital myopathy typically exhibit symptoms such as being "floppy," having difficulty breathing or feeding, and lagging behind other babies in meeting normal developmental milestones [8]. The weakness may also be associated with features of low muscle bulk and tone [7].

Causes and Inheritance

Congenital myopathies are genetic diseases that can be passed from parent to child. They have a genetic basis, meaning they are caused by mutations in specific genes [2].

References:

[1] Congenital myopathy is a rare inherited disorder that causes lack of muscle tone and muscle weakness in your baby.

[2] More specifically, myopathies are diseases that cause problems with the tone and contraction of skeletal muscles (muscles that control voluntary movements.)

[3] Congenital myopathies (CMs) are genetic diseases of the muscles connected to the skeleton. These disorders cause weakness in the muscles throughout the body.

[4] Congenital myopathies are a group of genetic muscle disorders characterized clinically by hypotonia and weakness, usually present from birth, with a static or slowly progressive clinical course.

[7] Oct 18, 2024 — The typical features of congenital myopathy include early-onset muscle weakness, often associated with features of low muscle bulk and tone.

[8] Typically, an infant with a congenital myopathy will be "floppy," have difficulty breathing or feeding, and will lag behind other babies in meeting normal developmental milestones.

Based on the provided context, here are the signs and symptoms of congenital myopathy:

• Muscle weakness: Congenital myopathies can cause severe, general muscle weakness that complicates basic activities like swallowing and breathing [2].
• Floppiness: Symptoms include face, arm, and leg weakness along with breathing difficulties [1].
• Breathing difficulties: Hard time breathing is a common symptom of congenital myopathy [3].
• Eating difficulties: Hard time eating due to muscle weakness [3].
• Delayed motor skills: Slow to reach developmental goals; Delayed motor (movement) skills [3].
• Scoliosis: Common to most congenital myopathies is severe weakness of the limbs and scoliosis [7].
• Breathing difficulties: Often breathing difficulties occur as well [7].
• Weakened eye movements: Some children have weakened eye movements [7].
• Muscle cramps, stiffness, and spasm: Other symptoms of myopathy can include muscle cramps, stiffness, and spasm [8].
• Symmetric muscle weakness: Most myopathies share the common symptom of symmetric muscle weakness (similar on both sides of your body), especially in proximal muscles [9].

These are some of the common signs and symptoms associated with congenital myopathy. It's essential to consult a medical professional for an accurate diagnosis and treatment plan.

Diagnostic Tests for Congenital Myopathy

Diagnosing congenital myopathies can be a complex process, but several diagnostic tests can help confirm the condition. Here are some of the key tests used to diagnose congenital myopathy:

• Muscle biopsy: This is a crucial test that involves taking a small sample of muscle tissue from the affected area. The biopsy is then examined under a microscope to look for specific structural and histochemical features that are characteristic of congenital myopathies [7][8].
• Electromyography (EMG) and nerve conduction studies (NCS): These tests measure the electrical activity of muscles and nerves, which can help identify muscle weakness or damage [5].
• MRI of muscles: In some cases, an MRI scan may be used to visualize the affected muscles and confirm the diagnosis [6].
• Blood test: A blood test can check for certain genetic markers that are associated with congenital myopathies [2].
• Genetic testing: This is a more specific test that can identify the underlying genetic cause of the condition. Genetic testing may involve sequencing technology to analyze the patient's DNA [10].

It's worth noting that diagnosing congenital myopathy often requires a combination of these tests, as well as a thorough medical history and physical examination.

References:

[5] Oct 18, 2024 — Electromyography (EMG) and nerve conduction studies (NCS). These studies test the electrical patterns of muscles and nerves. They can help to ...

[6] Diagnosis of congenital myopathies is suggested by characteristic clinical findings and is confirmed by muscle biopsy and sometimes MRI of muscles.

[7] Congenital myopathies are typically characterized by the presence of specific structural and histochemical features on muscle biopsy and clinical presentation ...

[8] by KN North · 2014 · Cited by 338 — Muscle biopsy and analysis of muscle histology, histochemistry, immunohistochemistry and ultrastructure by light and electron microscopy (EM) has been the ...

[10] Keywords: Congenital myopathy, Diagnosis, Guidelines. 1. Introduction. ... Molecular testing for congenital myopathies is in rapid evolution with recent advances in sequencing technology likely to have considerable impact on the method of genetic testing for these diseases.

Based on the available information, it appears that there are limited treatment options for congenital myopathies.

• Currently, there is no approved treatment for any type of congenital myopathy [3].
• Treatment options may include bracing or surgical correction with spinal fusion for scoliosis associated with congenital myopathy [2].
• Experimental treatments are still under development, and management of the disease involves treatment of symptoms and prevention of possible life-threatening complications [6].

In some cases, medications such as albuterol may be used to treat central core disease and multicore disease [5]. However, it's essential to note that these treatments are not curative and aim to manage the symptoms.

• Medications like checkpoint inhibitor immunotherapy (pembrolizumab, nivolumab), corticosteroids (prednisone), cholesterol-lowering drugs (statins), amiodarone, may be used in some cases [9].

It's crucial for individuals with congenital myopathy to consult with a team of experts at a reputable medical institution, such as Children's Health, to receive personalized guidance and treatment [7].

Differential Diagnosis of Congenital Myopathy

Congenital myopathies are a group of rare genetic muscle disorders that can be challenging to diagnose due to their overlapping clinical features with other conditions. The differential diagnosis for congenital myopathy includes several conditions, which are listed below:

• Spinal Muscular Atrophy (SMA): A genetic disorder characterized by muscle weakness and wasting, particularly in the lower limbs.
• Muscular Dystrophies: A group of inherited disorders that cause progressive muscle weakness and degeneration. Specific types include:
  • Duchenne Muscular Dystrophy (DMD): An X-linked recessive disorder causing severe muscle weakness and degeneration.
  • Becker Muscular Dystrophy (BMD): A milder form of DMD, also inherited in an X-linked recessive pattern.
• Congenital Muscular Dystrophies: A group of disorders characterized by muscle weakness and degeneration present at birth or early infancy.
• Myotonic Dystrophy Type 1: An autosomal dominant disorder causing progressive muscle stiffness and wasting.
• Metabolic Myopathies: A group of conditions caused by genetic defects in energy metabolism, including:
  • Pompe Disease: A lysosomal storage disorder leading to muscle weakness and degeneration.
• Congenital Myasthenic Syndromes: A rare group of disorders characterized by muscle weakness and fatigue due to impaired neuromuscular transmission.

These conditions can be distinguished from congenital myopathy based on specific clinical features, investigations, and muscle pathology. For instance:

• Muscle biopsy may show characteristic morphological features such as central cores or nemaline rods in certain types of congenital myopathies.
• Genetic testing can identify mutations in specific genes associated with these disorders.

References:

• [3] Congenital myopathy is a rare genetic condition that causes muscle weakness. Congenital means “present at birth” and myopathy means “disease of muscle.”
• [5] Differential diagnoses include DM1, CMS, SMA type 0, and Pompe disease.
• [7] Congenital myopathies are a group of genetic muscle disorders characterized clinically by hypotonia and weakness, usually from birth,
• [11] Congenital myopathies signify disorders associated with muscle weakness in the neonatal age group, which could be secondary to genetic, metabolic, or other disorders and usually have a non-progressive course.
• [13] The differential diagnosis of congenital myasthenic syndromes. Neonatal period, infancy, childhood. Spinal muscular atrophy. Congenital myopathies (central core disease, nemaline myopathy, myotubular myopathy) Congenital muscular dystrophies. Limb girdle or facioscapulohumeral dystrophy.
• [15] Differential diagnoses of congenital myopathies. The most important differential diagnoses of congenital myopathies are congenital muscular dystrophies, congenital myotonic dystrophy type 1, metabolic myopathies including Pompe disease, congenital myasthenic syndromes, and spinal muscular atrophy, which can all occur at neonatal age with severe...