The article presents a study which aims to determine the deletion for exon 7 survival motor neuron (SMN1) gene in Iranian patients with spinal muscular atrophy (SMA). The study used quantitative real-time polymerase chain reaction (PCR) to examine the SMA carriers in Iran. Results show that 52 patients were recognized as carriers, 26 patients were found to be normal for exon 7 deletions, and 15 patients were distinguished as homozygous for exon 7 deletion.