Spinal muscular atrophy

Uncommon card · No. 79931

Spinal muscular atrophy (SMA) is a rare neuromuscular disorder that results in the loss of motor neurons and progressive muscle wasting. It is usually diagnosed in infancy or early childhood and, if left untreated, it is the most common genetic cause of infant death. It may also appear later in life and then have a milder course of the disease. The common feature is the progressive weakness of voluntary muscles, with the arm, leg, and respiratory muscles being affected first. Associated problems may include poor head control, difficulties swallowing, scoliosis, and joint contractures. The age of onset and the severity of symptoms form the basis of the traditional classification of spinal muscular atrophy into several types. Spinal muscular atrophy is due to an abnormality (mutation) in the SMN1 gene which encodes SMN, a protein necessary for the survival of motor neurons. Loss of these neurons in the spinal cord prevents signalling between the brain and skeletal muscles. Another gene, SMN2...

Read on Wikipedia · Image Cervical vertebra blank.svg: Fred the Oyster Polio spinal diagram.PNG: DO11.10 Derived: Angelito7, CC BY-SA 4.0