RESUMEN
Hereditary pattern of spinal-muscular atrophy [SMA] disease is in form of recessive autosome with a frequency of 1 in 10000 live births. In most of the patients SMN1 gene bears deletions in exons 7 or 8. The aim of this study is to investigate deletion of above mentioned gene through molecular techniques in east Azarbaigan during 2004-2005. The patients likely to have SMA type III were referred to molecular study following the clinical and laboratory diagnosis. After extraction of DNA from patients' blood the extent of deletion in exons 7 and 8 of SMN1 gene, was investigated through PCR-Restriction Fragment Length Polymorphism [RFLP]. Out of 45 patients likely to have SMA type III, 9 people [20%] had exon deletion in SMN1 gene among whom one patient bore deletion only in exon 7 while the rest bore deletion in both exons [7, 8] of SMN1 gene. Deletion in SMN1 gene was observed in a low percent of the patients likely to have SMA type III. More research including the other sequences of SMN1 gene is recommended