Background/aim: Spinocerebellar ataxias (SCAs) are complex clinical and genetically heterogeneous, mostly autosomal dominant neurodegenerative diseases. At present, more than 30 hereditary SCA types have been associated with different gene mutations. In this study, the frequency distribution of the 6 SCA types 1, 2, 3, 6, 7, and 17 in the Turkish population was investigated with respect to clinical features.
Materials and methods: 159 patients who received a diagnosis of SCA and 42 healthy controls from Adana, Mersin, Gaziantep, Hatay, and Osmaniye provinces were included in the study. DNA samples were isolated from 2 mL blood samples and the number of trinucleotide repeats (TNRs) for each SCA type was detected using PCR-RFLP technique and sequencing.
Results: Of the 6 SCA types that were studied, 4 types, SCA 1, 3, 7, and 17, were positive and all heterozygous for expansions. SCA types 1 and 17 had higher frequencies, 4.4% and 3.8%, respectively, than SCA types 3 and 7. The clinical data of patients were also evaluated to correlate with the increased TNR numbers.
Conclusion: This study, being the first mutation record of SCAs in this area, indicated that 9.4% of cases belonged to 4 types, SCA 1, 3, 7, and 17.