Spinal Muscular Atrophy
Spinal Muscular Atrophy (SMA) is a neuromuscular disease that causes progressive wasting of the voluntary muscles.
There are four types of SMA. The most common, Type I, affects 50-70% of SMA children. Children with Type I SMA cannot sit unaided and over time become unable to swallow or control their secretions. Death from respiratory failure usually occurs by age 2. Types II-IV are less severe.
The only treatments currently available are supportive therapies such as ventilation to assist breathing and electric wheelchairs to improve mobility. However, researchers are exploring several promising avenues that may lead to better treatments in the future.
With a carrier frequency of 1 in 40, SMA is the most common recessive disorder fatal in infancy. Because it affects all ethnic groups, screening is available to anyone planning a pregnancy. Screening can detect 90-94% of carriers.