Types of Muscular Dystrophy

What is Muscular Dystrophy?

Muscular dystrophy is a group of inherited diseases where voluntary muscles are damaged and progressively weaken. It is due to the lack of a protein “dystrophin”, which is required for healthy muscular function. There is a loss of strength in muscles, which leads to difficulty in muscle coordination, walking and increases disability and deformation.

 

Muscular Dystrophy

 

Muscular dystrophy can occur at any stage of life but it mostly occurs in childhood. Young boys are more prone to disease. Individuals with the disease eventually lose their walking ability and need assistance to walk. There is no known cure although treatments may help in managing the symptoms.

 

Table of Content:

 

What are the Types of Muscular Dystrophy

There are mainly 9 types of muscular dystrophy which vary in symptoms, age of onset, severity and rate of progression. Some are named after the muscle they affect.

  1. Duchenne
  2. Myotonic
  3. Becker
  4. Congenital
  5. Facioscapulohumeral
  6. Limb-girdle
  7. Oculopharyngeal
  8. Distal
  9. Emery-Dreifuss

Muscular Dystrophy Symptoms

Type Age of onset Common Symptoms
Duchenne 2 to 6 years
  • Muscle weakness and problem in coordination
  • Trouble walking, running, jumping and standing up
  • Breathing difficulties, lung and heart weakness
  • Abnormal curvature of the spine (scoliosis)
  • Learn to speak later
  • Learning difficulties
  • Mostly found in boys
  • Life expectancy is not more than the 20s
Myotonic or Steinert’s disease 20 to 30 years
  • Muscle stiffness (myotonia)
  • Affects facial muscles and causes drooping of muscles
  • Poor vision, cataract
  • Excessive sleeping
  • Affects adrenal glands, and thyroid
  • Learning problems
  • Irregular heartbeat
  • Weakens neck muscles, difficulty in lifting the neck
  • May cause infertility or impotence
  • Progression is slow
Becker Adolescence 11-15 years
  • Similar to Duchenne but it’s less severe
  • Commonly affects boys
  • Muscle weakness of arms and legs
  • Muscle cramps and frequent falls
  • Trouble getting up, walking on the toes
  • Learn to walk late
Congenital By birth
  • Poor motor control

joint deformities, inability to sit or stand

  • Abnormal curvature of the spine (scoliosis)
  • Vision and speech problems
  • Respiratory problems
  • Trouble in swallowing (dysphagia)
  • Intellectual impairment
  • Shortened lifespan
Facioscapulohumeral Childhood to early adult
  • Weakness in facial muscles, shoulder and upper arms
  • Progression is slow with a rapid period deterioration
  • Crooked appearance of mouth, inability to purse lips
  • Inability to shut their eyes completely
  • Wing-like appearance of the shoulder blades
Limb-girdle Late childhood to middle age
  • Affects both male and females
  • Normal life expectancy
  • Loss of muscle mass
  • Affects pectoral and pelvic girdle
  • Difficulty in climbing stairs and getting up from the chair
  • Heart palpitations. Mostly die due to complications in the heart or lungs
Oculopharyngeal 40 to 50 years
  • Affects muscle of eyelids, throat and shoulder
  • Problem in swallowing leads to starvation
  • Drooping eyelids
  • Change in voice and vision problems
  • Occurs both in men and women
Distal 40 to 60 years
  • Progression is slow
  • Weakness and loss of muscles of hands, forearms, calves and feet
  • Affects both male and female
  • Loss of fine motor skills
  • Difficulty in walking
Emery-Dreifuss Childhood to early teens
  • Affects both boys and girls
  • Slow progression
  • Shortened muscles
  • Tightened tendons, limit the joint movements
  • Weakness of shoulder, upper arm and shin muscles
  • Heart and breathing problems
  • Sudden death from cardiac problems

Causes of Muscular Dystrophy

It is mostly caused by the mutation of genes that are responsible for the structure and function of muscle, leading to weakness in muscles and disability. The disease is caused due to interference in the formation of a protein called dystrophin which is required for normal functioning of muscles. Muscular dystrophy is mostly inheritable and runs in families. It can be sex-linked, recessive or dominant inherited disorder. Very rarely is it spontaneous where there is no history in a family.

Treatment

There is no cure for muscular dystrophy. Whatever treatments that are available, they only help in managing the condition and slowing the progression.

  • Steroid medication for strengthening muscles
  • Surgery to correct deformities, cataract and treat cardiac complications
  • Therapies like exercises to strengthen muscles, yoga is found to be helpful in making an individual more independent
  • Exercise or surgery to improve the swallowing problem
  • Ataluren is a new medicine to treat Duchenne disease patients of age 5 years or older who can still walk.

Lots of research is happening to develop new treatments for the disease. Some examples are exon skipping, use of stem cells to regenerate damaged muscle tissue.

Also Read: MCQs on Muscular Dystrophy for NEET 2020

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