 Spinal muscular atrophy, SMA, is among the most common autosomal recessive disorders with different incidence rates in different ethnic groups. In the current study, we have determined SMN1, SMN2 and NAIP copy numbers in an Iranian population using MLPASA. This article was authored by Shahram Sivad, Mammoud Rezo Shrafi, Niosha Samadayan, and others.