Spinal muscular atrophy (SMA) is a neurodegenerative disorder caused by the absence of the full length SMN protein (FL-SMN) as a result of mutation or deletion of SMN1 gene. The isoform to this gene, SMN2 gene, with mutation in 1 base pair, encodes for 10% of FL-SMN protein and is reported to decrease the severity of the disease when there is an increase gene dosage. There are 3 clinical types of SMA; type I, type II and type III. Type I SMA is the most severe type and only a small amount of FL-SMN protein is present in these individuals. We postulated that the difference in the promoter region of SMN2 gene produces the different level of FL-SMN protein. To verify this hypothesis, the DNA samples of 69 SMA patients who were referred to the Human Genome... |