Centronuclear myopathy (including myotubular myopathy)

Centronuclear myopathy is a group of rare, genetic muscle disorders characterized by muscle weakness and structural abnormalities in muscle cells. The term "centronuclear" refers to the central location of the cell nucleus in muscle fibers, which is a distinctive feature of these conditions. Centronuclear myopathies are part of a larger group of disorders known as congenital myopathies.

Classification

Centronuclear myopathies are classified into three main types based on the mode of genetic inheritance: X-linked myotubular myopathy (XLMTM), autosomal dominant centronuclear myopathy (ADCNM), and autosomal recessive centronuclear myopathy (ARCNM).

X-linked myotubular myopathy

X-linked myotubular myopathy (XLMTM) is the most severe form of centronuclear myopathy. It is caused by mutations in the MTM1 gene, which is located on the X chromosome. Symptoms usually appear at birth and include severe muscle weakness, respiratory problems, and difficulty swallowing.

Autosomal dominant centronuclear myopathy

Autosomal dominant centronuclear myopathy (ADCNM) is caused by mutations in the DNM2 or BIN1 genes. Symptoms typically appear in adolescence or early adulthood and include muscle weakness, difficulty walking, and facial weakness.

Autosomal recessive centronuclear myopathy

Autosomal recessive centronuclear myopathy (ARCNM) is caused by mutations in the BIN1, RYR1, or TTN genes. Symptoms can vary widely, from mild muscle weakness to severe respiratory problems.

Diagnosis

Diagnosis of centronuclear myopathy is based on clinical symptoms, family history, and genetic testing. Muscle biopsy may also be performed to examine the structure of muscle cells under a microscope.

Treatment

There is currently no cure for centronuclear myopathy. Treatment is supportive and aims to manage symptoms and improve quality of life. This may include physical therapy, respiratory support, and nutritional support.

Research

Research into centronuclear myopathy is ongoing, with efforts focused on understanding the underlying genetic and cellular mechanisms and developing effective treatments.

See also

• Muscular dystrophy
• Congenital myopathy
• Genetic disorder

NIH genetic and rare disease info

• NIH info on Centronuclear myopathy (including myotubular myopathy)

Centronuclear myopathy (including myotubular myopathy) is a rare disease.