Clinical profile and genetic correlation of patients with spinocerebellar ataxia: A study from a tertiary care centre in Eastern India

BACKGROUND: Progressive cerebellar ataxia inherited by autosomal dominant transmission is known as Spino Cerebellar Ataxia (SCA). AIMS AND OBJECTIVES: To look for various clinical profile and molecular genetics of patients with SCAs and their phenotype-genotype correlation of patients with SCAs. MATERIALS AND METHODS: This was a cross-sectional study conducted at Bangur Institute of Neurosciences, Kolkata from June 2010 to April 2013. We selected patients from the neurogenetic clinic of our institute and performed genetic test for SCA 1, 2, 3, 6 and 12. The diagnosis was based on suggestive clinical features and positive genetic study, done by polymerase chain reaction. RESULTS: 83 patients were tested for trineucleotide repeats and turned out 45 positive for the mentioned SCAs. We found 13(28.9%) SCA-1, 18(40%) SCA-2, 7(15.6%) SCA-3, 6(13.3) SCA-6 and 1(2.2%) SCA-12 patients. Half of the remaining 38 patients had positive family history. The mean age of onset were 38.46 years in SCA-1, 29.55 years in SCA-2, 38.43 years in SCA-3, 47.33 years in SCA-6. Slow saccades were observed in 7(53.8%) SCA-1, 17(94.4%) SCA-2, 4(57.1%) SCA-3, 3(50%) SCA-6 patients. Hyporeflexia was noticed in 5(27.8%) SCA-2 patients. Pyramidal tract involvement was found in 8(61.5%) SCA-1, 4(22.2%) SCA-2, 4(57.1%) SCA-3 and 1(16.7%) SCA-6 patients. CONCLUSION: Our study showed SCA-2 is the most common variety of SCA and genotypic-phenotypic correlation was observed in SCA-1,2,6 and 12 patients.