Types of Muscular Dystrophy and Neuromuscular Diseases

What are the different types of muscular dystrophy?

Muscular dystrophy is a group of inherited diseases characterized by weakness and wasting away of muscle tissue, with or without the breakdown of nerve tissue. There are 9 types of muscular dystrophy, with each type involving an eventual loss of strength, increasing disability, and possible deformity.

The most well known of the muscular dystrophies is Duchenne muscular dystrophy (DMD), followed by Becker muscular dystrophy (BMD).

Listed below are the 9 different types of muscular dystrophy. Each type differs in the muscles affected, the age of onset, and its rate of progression. Some types are named for the affected muscles, including the following:

Type

Age at onset

Symptoms, rate of progression, and life expectancy

Becker

adolescence to early adulthood

Symptoms are almost identical to Duchenne, but less severe; progresses more slowly than Duchenne; survival into middle age. As with Duchenne, disease is almost always limited to males.

Congenital

birth

Symptoms include general muscle weakness and possible joint deformities; disease progresses slowly; shortened life span.

Duchenne

2 to 6 years

Symptoms include general muscle weakness and wasting; affects pelvis, upper arms, and upper legs; eventually involves all voluntary muscles; survival beyond 20s is rare. Seen in boys only. Very rarely can affect woman, who have much milder symptoms and a better prognosis.

Distal

40 to 60 years

Symptoms include weakness and wasting of muscles of the hands, forearms, and lower legs; progression is slow; rarely leads to total incapacity.

Emery-Dreifuss

childhood to early teens

Symptoms include weakness and wasting of shoulder, upper arm, and shin muscles; joint deformities are common; progression is slow; sudden death may occur from cardiac problems.

Facioscapulohumeral

childhood to early adults

Symptoms include facial muscle weakness and weakness with some wasting of shoulders and upper arms; progression is slow with periods of rapid deterioration; life span may be many decades after onset.

Limb-Girdle

late childhood to middle age

Symptoms include weakness and wasting, affecting shoulder girdle and pelvic girdle first; progression is slow; death is usually due to cardiopulmonary complications.

Myotonic

20 to 40 years

Symptoms include weakness of all muscle groups accompanied by delayed relaxation of muscles after contraction; affects face, feet, hands, and neck first; progression is slow, sometimes spanning 50 to 60 years.

Oculopharyngeal

40 to 70 years

Symptoms affect muscles of eyelids and throat causing weakening of throat muscles, which, in time, causes inability to swallow and emaciation from lack of food; progression is slow.

What are other neuromuscular diseases?

Spinal muscular atrophies:

  • Amyotrophic lateral sclerosis (ALS), or motor neuron disease

  • Infantile progressive spinal muscular atrophy

  • Intermediate spinal muscular atrophy

  • Juvenile spinal muscular atrophy

  • Adult spinal muscular atrophy

Inflammatory myopathies:

  • Dermatomyositis

  • Polymyositis

  • Inclusion body myositis

Diseases of peripheral nerve:

  • Charcot-Marie tooth disease

  • Dejerine-Sottas disease

  • Friedreich's ataxia

Diseases of the neuromuscular junction:

  • Myasthenia gravis

  • Lambert-Eaton syndrome

  • Botulism

Metabolic diseases of the muscle:

  • Acid maltase deficiency

  • Carnitine deficiency

  • Carnitine palmityl transferase deficiency

  • Debrancher enzyme deficiency

  • Lactate dehydrogenase deficiency

  • Mitochondrial myopathy

  • Myoadenylate deaminase deficiency

  • Phosphorylase deficiency

  • Phosphofructokinase deficiency

  • Phosphoglycerate kinase deficiency

Less common myopathies:

  • Central core disease

  • Hyperthyroid myopathy

  • Myotonia congenita

  • Myotubular myopathy

  • Nemaline myopathy

  • Paramyotonia congenita

  • Periodic paralysis-hypokalemic-hyperkalemic