Hereditary inclusion body myopathy

Hereditary inclusion body myopathy
Synonyms	Inclusion body myopathy 2, GNE myopathy, Nonaka myopathy
Pronounce	N/A
Specialty	N/A
Symptoms	Progressive muscle weakness, especially in the distal muscles
Complications	N/A
Onset	Typically in early adulthood
Duration	Chronic
Types	N/A
Causes	Mutations in the GNE gene
Risks	Genetic predisposition, particularly in certain ethnic groups
Diagnosis	Genetic testing, Muscle biopsy
Differential diagnosis	Muscular dystrophy, Polymyositis, Inclusion body myositis
Prevention	N/A
Treatment	No cure, supportive care, physical therapy
Medication	N/A
Prognosis	Progressive, leading to significant disability
Frequency	Rare, varies by population
Deaths	N/A

=Hereditary Inclusion Body Myopathy = Hereditary Inclusion Body Myopathy (HIBM) is a group of rare genetic disorders characterized by progressive muscle weakness and wasting. These conditions are also known as GNE myopathy, distal myopathy with rimmed vacuoles, or Nonaka myopathy.

Overview

HIBM typically presents in early adulthood and progresses slowly over time. The disease primarily affects the muscles of the lower limbs, but can eventually involve other muscle groups.

Genetics

HIBM is most commonly caused by mutations in the GNE gene, which encodes an enzyme involved in sialic acid biosynthesis. Sialic acid is important for muscle function, and its deficiency leads to the symptoms observed in HIBM.

Inheritance

HIBM is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disease.

Symptoms

The primary symptoms of HIBM include:

• Progressive muscle weakness, especially in the lower limbs
• Difficulty walking and climbing stairs
• Muscle atrophy
• Foot drop

Diagnosis

Diagnosis of HIBM involves a combination of clinical evaluation, genetic testing, and muscle biopsy.

Genetic Testing

Genetic testing can confirm the presence of mutations in the GNE gene.

Muscle Biopsy

A muscle biopsy may show characteristic features such as rimmed vacuoles and inclusion bodies.

Treatment

Currently, there is no cure for HIBM, but treatment focuses on managing symptoms and improving quality of life.

Physical Therapy

Physical therapy can help maintain muscle strength and mobility.

Orthopedic Devices

Devices such as braces or orthotics can assist with mobility and support.

Research

Research is ongoing to better understand the pathophysiology of HIBM and to develop potential therapies. Gene therapy and enzyme replacement therapy are areas of active investigation.

See Also

• Muscular Dystrophy
• Genetic Disorders
• Neuromuscular Diseases
• "GNE Myopathy: A Review of the Current State of Research and Therapeutic Strategies".Journal of Neuromuscular Diseases.2020;7(4)

387-399.doi:10.3233/JND-200520.

• Ikuya,

 Distal Myopathy with Rimmed Vacuoles, 
  
 Springer, 
 2015, 
  
  
 ISBN 978-3-319-12345-6,

External Links

• Muscular Dystrophy Association: GNE Myopathy
• NIH Genetic and Rare Diseases Information Center

NIH genetic and rare disease info

• NIH info on Hereditary inclusion body myopathy

Hereditary inclusion body myopathy is a rare disease.