Type II Spinal Muscular Atrophy (SMA) is a rare genetic disorder characterized by progressive muscle weakness and atrophy. It is classified as a neurodegenerative disease and is caused by mutations in the survival motor neuron 2 (SMN2) gene.
Individuals with Type II SMA typically start experiencing symptoms in infancy or early childhood. The severity of the condition can vary, but typically affected individuals are able to sit independently but have difficulty standing or walking without support. Muscle weakness progresses over time, affecting various parts of the body including the arms, legs, and respiratory muscles.
Motor milestones are delayed in individuals with Type II SMA, and many have difficulty with activities such as crawling or walking. Despite muscle weakness and mobility challenges, individuals with Type II SMA generally have a normal lifespan and have the ability to participate in various activities with assistance.
Other symptoms commonly associated with Type II SMA include weakness and atrophy of muscles in the face, bulbous nose, high-arched palate, scoliosis, feeding difficulties, and respiratory problems.
There is currently no cure for Type II SMA, but management involves supportive care to maintain function and improve quality of life. This may include physical therapy, assistive devices such as braces or wheelchairs, respiratory support, and nutritional support. Additionally, there are emerging treatments, such as spinal muscular atrophy gene therapy, that show promise in improving outcomes for individuals with Type II SMA.
