Sma disease: Spinal muscular atrophy ( SMA )

Spinal muscular atrophy ( SMA ) is characterized by muscle weakness and atrophy resulting from progressive degeneration and irreversible loss of the anterior horn cells in the spinal cord (i.e., lower motor neurons) and the brain stem nuclei. The onset of weakness ranges from before birth to adulthood. The weakness is symmetric, proximal greater than distal, and progressive. Before the genetic basis of SMA was understood, it was classified into clinical subtypes based on maximum motor function ... Spinal muscular atrophy affects individuals of all ethnic groups, unlike other well-known autosomal recessive disorders, such as sickle cell disease and cystic fibrosis, which have significant differences in occurrence rate among ethnic groups. What is spinal muscular atrophy ( SMA )? Spinal muscular atrophy ( SMA ) is a group of genetic diseases that damages and kills motor neurons. Motor neurons are a type of nerve cell in the spinal cord and lower part of the brain. They control movement in your arms, legs, face, chest, throat, and tongue. As the motor neurons die off, your muscles start to weaken and atrophy (waste away). The muscle damage gets worse over time and can affect speaking, walking, swallowing, and breathing. What are ... Learn about SMA , a group of hereditary diseases that affect motor neurons and cause muscle weakness and atrophy. Find out about diagnosis, treatment, and latest updates on SMA research.