Clinical features, DYT1 mutation screening and genotype-phenotype correlation in patients with dystonia from Iran

To test Iranian patients with primary torsion dystonia to determine the frequency of 904-906 del GAG mutation in the DYT1 [TOR1A] gene and to investigate the genotype-phenotype association for this disease. Subjects and Methods: Sixty-three patients with primary dystonia were investigated. DMA was extracted from peripheral blood and these samples were subjected to PCR-sequencing for exon 5 of the DYT1 gene. Results: Of the 63 patients, 10 [15.9%] carried the triplet GAG deletion mutation; this is a high DYT1-positive rate in comparison with other populations and the type of dystonia in this positive group was generalized in all except 1. In our patients, limbs were the most severely involved site at the time of onset and in most cases it developed to generalized form. The majority of DYT1-positive cases showed higher leg onset [5 patients, 62.5%] in comparison with higher arm onset in negative patients [20 patients, 50%]. Also, the progression to generalized dystonia in DYT1-positive patients was significantly higher than in DYT1-negative patients. The mean age at onset was 8.6 +/- 1.6 years [7-12 years] in D/H-positive patients, while mean age at onset in patients with no GAG deletion mutation was higher [15.7 +/- 11.5 years]. The DYT1 904-906 del GAG mutation is responsible for some of Iranian dystonia patients, and screening for the DYT1 deletion is significant in cases with the generalized type of primary dystonia. Also, patients with leg or arm onset at a younger age are more likely to be DYT1-positive among primary torsion dystonia Cases

frequency of DYT1 [GAG deletion] mutation in primary dystonia patients from Iran

To determine the frequency of DYT1 mutation in Iranian patients affected with primary dystonia. in this study, we investigated 60 patients with primary dystonia who referred to the Tehran Medical Genetics Laboratory [TMGL] to determine the deletional mutation of 904-906 del GAG in the DYT1 gene, DNA extracted from patients' peripheral blood was subjected to PCR-sequencing for exon 5 of the DYT1 gene. The collection of samples was based on random sampling. The deletional mutation of 904-906 del GAG in the DYT1 gene [15099 to 15101 based on reference sequence: NGJ308049.1] was identified in 11 patients [18.33%]. The average age of affected patients with this mutation was 13.64 +/- 7.4 years. Conclusion: It can be concluded that the DYT1 deletional mutation of 904-906 del GAG has a high frequency in Iranian patients in comparison with other non-Jewish populations. Therefore, this particular mutation may be the main representative of pathogenic DYT1 gene for a large proportion of Iranian patients with primary dystonia