Magazine article The Exceptional Parent

August Is Spinal Muscular Atrophy Awareness Month! Spinal Muscular Atrophy (SMA) Is a Motor Neuron Disease in Which the Motor Neurons Affect the Voluntary Muscles That Are Used for Activities Such as Crawling, Walking, Head and Neck Control, and Swallowing. It Is the Number One Genetic Killer of Children under the Age of Two

Magazine article The Exceptional Parent

August Is Spinal Muscular Atrophy Awareness Month! Spinal Muscular Atrophy (SMA) Is a Motor Neuron Disease in Which the Motor Neurons Affect the Voluntary Muscles That Are Used for Activities Such as Crawling, Walking, Head and Neck Control, and Swallowing. It Is the Number One Genetic Killer of Children under the Age of Two

Article excerpt

THE BASICS

SMA affects muscles throughout the body, although the proximal muscles (those closest to the trunk of one's body--i.e. shoulders, hips, and back) are often most severely affected. Weakness in the legs is generally greater than in the arms. Sometimes, feeding and swallowing can be affected. Involvement of respiratory muscles (muscles involved in breathing and coughing) can lead to an increased tendency for pneumonia and other lung problems. Sensation and the ability to feel, as well as intellectual activity, are not affected. Patients are generally grouped into one of four categories, based on certain key motor function milestones.

SMA is an autosomal recessive genetic disease. In order for a child to be affected by SMA, both parents must be carriers of the abnormal gene and both must pass this gene on to their child. Although both parents are carriers the likelihood of a child inheriting the disorder is 25%, or 1 in 4.

An individual with SMA has a missing or mutated gene (SMN1, or survival motor neuron 1) that produces a protein in the body called Survival Motor Neuron (SMN) protein. This protein deficiency has its most severe affect on motor neurons. Motor neurons are nerve cells in the spinal cord, which send out nerve fibers to muscles throughout the body. Since SMN protein is critical to the survival and health of motor neurons, without this protein nerve cells may shrink and eventually die, resulting in muscle weakness.

As a child with SMA grows, their bodies are doubly stressed, first by the decrease in motor neurons and then by the increased demands on the nerve and muscle cells as their bodies grow larger. The resulting muscle atrophy can cause weakness and bone and spinal deformities that may lead to further loss of function, as well as additional compromise of the respiratory (breathing) system.

WHO IS AFFECTED?

SMA is one of the most prevalent genetic disorders.

* One in every 6,000 babies is born with SMA.

* SMA can strike anyone of any age, race, or gender. …

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