What is SMA?
SMA stands for spinal muscular atrophy. It is the #1killer of infants and young children. There is no treatment and there is no cure. It is a degenerative genetic disease affecting the part of the nervous system that controls voluntary muscle movement, eventually hindering the ability to walk, stand, eat, speak, breathe and swallow. The mind is never affected. An SMA patient has the ability to think, learn and build relationships.
The acronym SMA reveals the effects it has on the body.
Spinal: SMA involves the loss of nerve cells called motor neurons in the spinal cord.
Muscular: SMA reveals itself because if its primary effect on the muscles, which don’t receive neural signals, and are therefore never stimulated to move.
Atrophy: The lack of neural stimulation and muscular action leads to the muscles getting smaller and weaker over time.
What causes SMA?
SMA is a caused by a genetic mutation in the survival motor neuron gene 1 (SMN1). In a healthy person, this gene produces a protein that is critical to the function of the nerves that control our muscles. Without it, those nerve cells cannot properly function and eventually die, leading to debilitating and often fatal muscle weakness.
How Common Is SMA?
SMA affects approximately 1 in 6,000 – 10,000 babies, and about 1 in every 50 Americans is a genetic carrier. SMA can affect any race or gender.
Are All SMA Cases The Same?
No, there are broad ranges of onset and severity. SMA is officially divided into four distinct types.
Type 1
Symptoms Present by 6 Months
The most severe form of the disease, Type 1 SMA symptoms are present during infancy. Affected children will not acquire the power, the strength, and the endurance to sit up independently, to crawl, or to walk. The challenge of basic respiration often poses the most critical risks to the health of an SMA 1 patient. It takes a team, usually captained by the family, and implemented in a neuromuscular center to meet the needs to provide for the ultimate healthcare support for a Type 1 infant.
Type 2
Symptoms Present by 18 Months
Type 2 SMA usually comes to medical attention before the age of 18 months because of respiratory insufficiencies experienced by the child. Early motor milestones, such as achieving head control, turning and rolling in the crib, are frequently passed on time. SMA 2 presents a significant list of medical challenges, and the potential for surgical interventions may be more frequent; a child affected by Type 2 is unlikely to walk unassisted.
Type 3
Symptoms Present by 6 Months
The most severe form of the disease, Type 1 SMA symptoms are present during infancy. Affected children will not acquire the power, the strength, and the endurance to sit up independently, to crawl, or to walk. The challenge of basic respiration often poses the most critical risks to the health of an SMA 1 patient. It takes a team, usually captained by the family, and implemented in a neuromuscular center to meet the needs to provide for the ultimate healthcare support for a Type 1 infant.
Type 4
Onset In Adulthood
Diagnosed after the age of 18 and by the age of 50, the symptoms of Type 4 SMA can otherwise be similar to that seen in Type 3, including muscle wasting, weakness, and tremors. The muscles used for swallowing and breathing are less likely to be affected in adult onset SMA.
What are the symptoms of SMA?
SMA symptoms cover a broad spectrum ranging from mild to severe.
The primary symptom of SMA is weakness of the voluntary muscles. The muscles most affected are those closest to the center of the body, such as those of the shoulders, hips, thighs and upper back. Special complications occur if the muscles used for breathing and swallowing are affected, resulting in abnormalities in these functions. If the muscles of the back weaken, spinal curvatures can develop.
There’s a great deal of variation in the age of onset and level of motor function achieved in chromosome 5-related SMA. These are roughly correlated with how much functional SMN protein is present in the motor neurons, which in turn is correlated with how many SMN2 genes a person has.
What Is The Progression of SMA?
In chromosome 5-related SMA, the later the symptoms begin and the more SMN protein there is, the milder the course of the disease is likely to be. While in the past, infants with SMA typically did not survive more than two years, today most doctors now consider SMN-related SMA to be a continuum and prefer not to make rigid predictions about life expectancy or weakness based strictly on age of onset.
The Addy Grace Foundation (AGF) is a 501c3 nonprofit organization focused on raising awareness of Spinal Muscular Atrophy (SMA). Our mission is to help build relationships and be a source of encouragement to families affected by SMA. We provide support to families receiving this life-altering diagnosis in their children and continuing to live life one day at a time. Over the years the AGF has provided funds directly to families struggling with the disease. We have provided for the purchase of breathing machines, specialized strollers, therapy equipment, hospital bills, and more.