Background and Objectives: The neuromuscular degenerative disorder, known as spinal muscular atrophy (SMA), is a common fatal disease in neonates. In most patients with SMA, exon 7 and/or exon 8 of SMN1 gene is deleted. It is reported that the deletion of exon 5 from NAIP gene may be involved in the severity of SMA disease. The present study was aimed to evaluate the genotype- phenotype correlation of SMN1 and NAIP genes in SMA patients of East Azerbaijan.
Materials and Methods: We analyzed SMN1 and NAIP genes in SMA patients referred from East Azerbaijan province using molecular methods. The genome of SMA patients, diagnosed by neurologists, was analyzed for exons 7 and 8 of SMN1 gene and exon 5 of NAIP gene using PCR-RFLP and Multiplex-PCR techniques, respectively.
Results: Homozygous deletions of SMN1 were detected in 90% of SMA Patients. Exon 5 from the NAIP gene was deleted in 54.5% of patients and its deletion was more frequent in SMA type I (75%) as compared to type II (18%) and type III (7%).
Conclusion: The results further support that the analysis of the SMN1 gene may be used for confirming clinical manifestations of SMA, while the analysis of NAIP gene can be used to determine the severity of the disease.