DMD

What is the cause of muscular dystrophy?

Muscular Dystrophy is caused by a defect in genes that are important for healthy muscle protein. Genes are collection of DNA, which acts as "blueprint" for the protein synthesis - cell growth and activity. They are located on the chromosomes, inside the nucleus of every cell. They are usually in pairs with one inherited from each parent. Every third case of muscular dystrophy is caused by a spontaneous mutation of a gene where there is no family history of the condition. Each gene carries instructions for the production of a specific protein. Proteins are substances that have many functions necessary for the healthy life of a cell. A protein abnormality results from a defective gene. The abnormality could be the absence of an important protein or in improper proportion/amount/function. This protein abnormality causes wasting and improper function of a muscle, which leads to atrophy. And damaged muscle cells are replaced with fat and fibrous tissue. Symptoms may not appear until 50% of muscle tissue has been affected.

There are several types of muscular dystrophy that affect different groups of muscles and arise at different ages.
The major types are:

Duchenne Muscular Dystrophy.
Becker Muscular Dystrophy.
Facioscapulohumeral Muscular Dystrophy.
Limb-Girdle Dystrophy.
Myotonic Dystrophy.
Congenital Dystrophy.
Oculopharyngeal Dystrophy.

(a) Symtoms and Signs of Muscular Dystrophy.

Babies usually appear normal during early infancy. In childhood he/she may have difficulty while breathing, catch cough and cold, fever very often, have difficulty while swallowing the food, may face difficulty while crawling and may not be able to get up and walk on his/her own. The child may face difficulty in speech. A few affected children are late in learning to walk and unable to run very fast. The child falls frequently. The involuntary muscles like those of bladder or bowel are affected which causes difficulty while passing the urine and stool. All these early signs are often overlooked.

As the disease progresses, the calf - muscles start to look abnormally large due to replacement of damaged muscle cells with fat and fibrous tissue. Child faces difficulty while climbing the stairs. Contractures occur at the ankles, knees and hips, which causes the child to walk on his toes with the knees a little bent and feet apart. Because of weakness in the hip, knee & trunk muscles it is difficult to keep his/her balance while standing and walking. Front upper chest muscles are atrophied. The weakness of muscles causes the child to getup from lying in a typical way by rolling on his face & using the arms to push him and then the disease progressively takes control causing gradual and relentless destruction of the muscle tissue until the child needs to use a wheelchair. Sitting and lying down becomes difficult and uncomfortable because of stiffening in the lower body, skeletal deformities develop in the later stages and respiratory muscles become weak and these children find it difficult to recover from chest infections and death occurs from pneumonia or cardiac failure consequent upon an associated cardiomyopahty.

(b) Investigation
Family history
Past histories
Clinical Examination: muscle tone, mass and strength.
Estimation of Creatine Kinase (CK) - NAC & MB, SGPT, SGOT, LDH, LDH1, Growth Hormone.
Electromyography (EMG).
Muscle Biopsy
DNA Report. (Deoxyribonucleic Acid)
Shiv Shakti Chetana Kendra
13-B, Ambicanagar-3, outside Chhani Jakatnaka, Near Narmada canal, Vadodara-390002. Gujarat, India, Phone: +91-265-2761952