Spinal muscular atrophy (SMA) is a genetic neuromuscular disease. Here are some quick SMA stats:


It's the number 1
genetic cause of infant death


As many as 1 in 10,000
live births may be affected


6,000,000 people or 1 in 50
americans are genetic carriers


SMA can affect people
of any race or gender


Survivors REQUIRE lifelong care
and support

There are four types of SMA:

Type 1 (also called werdnig-hoffman disease) is the most severe

Early onset with diagnosis usually in an infant's first 6 months

Most severe type with 90% mortality or need for permanent ventilation support by 2 years old

60% of all sma cases are type 1

Type 1 symptoms:

  • Hypotonia (also called "floppy baby syndrome"): Characterized by abnormal limpness in the neck and limbs
  • Muscle weakness (particularly in the legs)
  • Poor head control
  • Abdominal breathing (also called diaphragmatic or belly breathing): Characterized by breathing through the contracting of the diaphragm rather than the chest
  • Bulbar muscle weakness: Exhibited by a weak cry, difficulty swallowing and aspiration
  • Inability to sit unsupported

Type 2 (also called Dubowitz Disease)

  • Onset between 6 to 18 months of age
  • Reduced life expectancy; 68% alive at age 25
  • Will never be able to walk without support
  • Most will never stand without support

Type 3 (also called Kugelberg-Welander disease or juvenile SMA)

  • Onset after 18 months
  • Can be diagnosed as late as the teenage years
  • Individuals affected are initially able to walk but have increasingly limited mobility as they grow

Type 4 (Adult Onset)

  • Very rare
  • Symptoms can start as early as 18 years but usually begin after age 30
  • Mobility characteristics are similar to Type 3

More SMA resources

Check Orphan

This nonprofit organization is dedicated to people working with or affected by rare, orphan or neglected

Cure SMA

Dedicated to the treatment and cure of spinal muscular atrophy (SMA), they fund groundbreaking
research and provide families the support they need for today.

Muscular Dystrophy Association

The world’s leading nonprofit health organization sponsoring research seeking causes and effective
treatments for neuromuscular diseases.

National Institute of Neurological Disorders and Stroke

NINDS seeks fundamental knowledge about the brain and nervous system in order to reduce the
burden of neurological disease.

SMA Europe

The purpose of SMA Europe is to provide a framework to stimulate collaboration and accelerate
translational research pathways in SMA and promote patient care.

SMA Foundation

Established by Loren Eng and Dinakar Singh, parents of a child with SMA, to accelerate the
development of treatment as the leading SMA research funder.

SMA News Today

This science and health web publication provides SMA news, education, and occasional insights about
clinical trials in the SMA research community.

The Gwendolyn Strong Foundation

Born from the Strong family’s firsthand experience with SMA Type 1, they are dedicated to increasing
global SMA awareness, research and family support.

The Sophia’s Cure Foundation

Formed by Catherine and Vincent Gaynor, shortly after their daughter was diagnosed with SMA, to
assist in clinical research funding and family support.


A network for the neuromuscular field that provides an infrastructure to ensure the most promising new
therapies reach patients as quickly as possible.