Spinal Muscular Atrophy Research Paper

Spinal muscular atrophy (SMA) is inherited disorder that affects the lower motor neuron in the anterior horn cells of the spinal cord and brain stem resulting in progressive weakness of the skeletal muscles [1]. It is considered as one of the most common autosomal recessive diseases and leading genetic cause of death during childhood [2]. The primary cause of SMA is mutation of the spinal motor neuron 1 (SMA1) while the severity of the disease is determined by the number of identical spinal motor neuron 2 (SMN2) [3, 4]. Kolb et al. reported that the incidence of SMA is around one in 6000–10 000 neonates [5]. SMA classified into four types according to the onset age and the maximum function attained. Zerres et al. determined that the SMA characterized by a progressive manner in the four types, which is severe in type I and mild in types II, III, IV [6]. …show more content…
Type II SMA is recognized after age six by onset of muscle weakness and hypotony and the patients are able to sit but need support to walk. In the type III SMA, Kugelberg-Welander disease, it occurs at age of 18 months; and the patients have the ability to walk. Type IV SMA is a mild form with an adult onset of muscle weakness [5]. Lunn et al. demonstrated that 95 % of SMA patients have a homozygous disturbance in the SMN1 gene on chromosome 5q, caused by mutation, deletion, or rearrangement. However, one copy of SMN2 is present in all SMA patients which provide only 10 % of the full length of SMN protein [7]. According to this fact the activation of SMN2 can used as a plan to treat the SMA patients for providing the full protein