What is Centronuclear myopathy?

Centronuclear myopathy (CNM) is an umbrella term for a group of rare genetic muscle disorders. These disorders are characterized by muscle weakness that can range from mild to profound.

What is the cause of Myotubular myopathy?

What causes myotubular myopathy? This disease is caused by defects or deficiencies of myotubularin, a protein thought to promote normal muscle development. It is inherited in an X-linked recessive pattern, meaning it primarily affects boys, who inherit the disease through their mothers.

What are the signs and symptoms of central core disease?

Most people with central core disease experience persistent, mild muscle weakness that does not worsen with time. This weakness affects the muscles near the center of the body (proximal muscles), particularly muscles in the shoulders, upper legs, and hips.

What is RYR1 myopathy?

RYR1 variants are the most common cause of muscle weakness present from birth (congenital myopathy). The RYR1 gene contains instructions for the body’s cells to produce a protein called the ryanodine receptor (RyR1) which is important for muscle function [2].

How common is centronuclear myopathy?

The incidence of all congenital myopathies (including central core disease, multi-minicore disease, nemaline myopathy and centronuclear myopathy) is estimated at around 0.06/1,000 live births, or one-tenth of all cases of neuromuscular disorders [3].

How is Myotubular myopathy diagnosed?

How is myotubular myopathy diagnosed? In addition to signs of muscle weakness, MTM has other features that will help physicians make the diagnosis. These include a high forehead, a long face, a large head, long fingers and toes, droopy eyelids, and undescended testicles.

What is Myotubular myopathy?

Summary. X-linked myotubular myopathy (XLMTM) is a rare genetic neuromuscular disorder that is characterized by muscle weakness that is most typically severe but can range from mild to profound. Symptoms are often present at birth, though may develop later in infancy or early childhood.

What is RYR1 mutation?

Mutations or changes in the RYR1 gene are the most common cause of congenital muscle myopathy. The RyR1 receptor is a channel in muscle cells that regulate the flow of calcium, a critical component of muscle contraction. A reduced number and/or abnormal RyR1 channels lead to dysfunctional muscle contraction.

Is RYR1 muscular dystrophy?

This highlights the potential for RYR1 pathogenic variants to produce pathological findings most consistent with congenital muscular dystrophy. Keywords: Congenital muscular dystrophy; Congenital myopathy; Myofiber degeneration; RYR1; p.

Is centronuclear myopathy inherited?

When centronuclear myopathy is caused by mutations in the DNM2 gene, it is inherited in an autosomal dominant pattern , which means one copy of the altered DNM2 gene in each cell is sufficient to cause the disorder.