EVALUATING THE DELETION AND POINT MUTATIONS OF THE SMN1 GENE IN PATIENTS WITH SPINAL MUSCULAR ATROPHY (SMA) IN WEST AZERBAIJAN PROVINCE OF IRAN

Spinal muscular atrophy (SMA) is a common disorder with autosomal recessive inheritance pattern. The
frequency of carriers of this disease is one in forty to one in sixty. SMA occurs in 98% of cases due to the homozygous deletion of SMN1
exons 7 and 8. The purpose of this study was to evaluating the deletion and point mutations of the SMN1 gene in patients with SMA
in west Azerbaijan province of Iran.
Materials & Methods: A total of 50 patients with SMA were referred to the Genetic Department after clinical diagnosis for molecular
evaluation and genetic counseling. Genomic DNA was extracted from blood samples. The exclusion rate of exons 7 and 8 in the
neuronal survival gene 1 was determined by using the PCR-RFLP. Results: Deletion of exons 7 and 8 were observed in 98% of the
studied cases (49 out of 50 cases). In one patient, the sequencing of exon 5 showed homozygote mutation c.549 del C (p.Lys184ser fs
29) (point mutation).
Conclusion: The evaluation of the presence or absence of exons 7 and 8 of the SMN1 gene, as well as point mutations in SMN1 gene
in patients suspected of musculoskeletal atrophy, is effective in confirming the clinical diagnosis and subsequent genetic counseling.