Medical professionals consider spinal muscular atrophy, also known as SMA, a hereditary motor neuron disease that impacts the lower motor neuron-nerve cells within the brainstem and spinal cord, which are responsible for voluntary muscle control. SMA gradually destroys the lower motor neurons and the patient’s ability to control movement in the face, tongue, throat, chest, arms, and legs, by disrupting signals from the brain to the muscles, and causing severe muscles spasticity (or stiffness), muscle wasting and fasciculations (uncontrolled twitching), and eventual and total loss of voluntary muscle movement. SMA is considered fatal as patient’s will eventually suffer a complete loss of chest muscle function, and succumb to respiratory failure. Spinal muscular atrophy is classified in 3 types, which often differ based on age of onset, symptoms, and disease severity: SMA Type 1 Also known as Werdnig-Hoffman disease and infantile-onset SMA presents in children 6 months old or younger. Children with SMA type 1 never stand or sit, and are prone to death due to respiratory failure prior to 2-years of age. The symptoms include: Weak fetal movements during early pregnancy Loss of tendon reflexes Decreased limb motion Fasciculations and tremors Severely compromised muscle tone, known as hypotonia Swallowing, feeding, and breathing impairments Skeletal abnormalities (scoliosis) SMA Type II The second type of spinal muscle atrophy strikes children between the ages of 6- and 18-months old.