THE DISEASE

Spinal muscular atrophy (SMA), the number one genetic killer of children under the age of two, is a group of inherited and often fatal diseases that destroys the nerves controlling voluntary muscle movement, which affects crawling, walking, head and neck control, and even swallowing.

WHO IS AFFECTED?

SMA is one of the most prevalent genetic disorders.

	One in every 6,000 babies is born with SMA. Of children diagnosed before age two, 50 percent will die before their second birthday.
	SMA can strike anyone of any age, race or gender.
	One in every 40 people carries the gene that causes SMA. The child of two carriers has a one in four chance of developing SMA.

THE TYPES OF SMA

SMA Patients are classified into four types based on milestones achieved at onset of SMA. Type I and II are most prevalent.

	Type 1, or Werdnig-Hoffmann Disease, is the most severe form of SMA. Type I SMA strikes infants between birth and six months old. Children affected with Type I cannot sit without support. Fifty percent of Type I babies will die before their 2nd birthday.
	Type II affects infants between seven and 18 months old. Type II patients may be able to sit unaided or even stand with support. They are at increased risk for complications from respiratory infections.
	Type III, also known as Kugelberg-Welander Disease, is the least deadly form of childhood-onset SMA. It strikes children as early as the age of 18 months, but can surface as late as adolescence. Type III patients are able to walk, but weakness is prevalent. Most patients eventually need to use a wheelchair.
	Type IV is the adult form of the disease. Symptoms tend to begin after age 35.

SMA does not affect sensation and intellectual activity in patients. It commonly is observed that patients with SMA are unusually bright and sociable.