Session Information
Date: Monday, September 23, 2019
Session Title: Ataxia
Session Time: 1:45pm-3:15pm
Location: Les Muses, Level 3
Objective: To report the phenotype among the largest number of genotypically confirmed SCA 12 patients.
Background: SCA12 is an autosomal dominant cerebellar ataxia (ADCA) caused by expansion of CAG trineucleotide repeat in PPP2R2B gene on chromosome 5q31-33. It is one of the common SCA in India.
Method: To date more than 4000 families have been screened for various SCAs 1, 2, 3, 6, 12, 17, DRPLA and FRDA in Ataxia clinic at AIIMS, New Delhi. A total of 339 subjects were genetically confirmed as SCA 12. The diagnosis was based on suggestive neurological history, examination, radiology, electrophysiology and CAG repeat screening of the genomic DNA. We analyzed clinical features of 102 (67M and 35F) consecutive patients out of these 339.
Results: The average disease duration was 6.50 ±5.1; with age at presentation 53.4± 10.1 and age at onset = 46.8 ± 10.6. The hand tremor was the presenting complaint in 65.7 % and gait ataxia in 14.7 %. Other less frequent presenting complaints were head tremor (8.8%), dysarthria (5.9%), upper limb in-coordination (3.9%) and writing difficulty in (1%). An inverse correlation of CAG repeats was observed with age at disease onset. Nystagmus was observed in 19.8% and extrapyramidal signs in 11.9% subjects. MRI was abnormal (cerebral atrophy, cerebellar atrophy or both) in about 90% patients. Nerve Conduction studies revealed normal study in 26.9%, sensory neuropathy in 8.9%, motor in 5 %, and sensori-motor in 6.9% out of 48 patients.
Conclusion: SCA 12 is one of the commonly found SCA in India. This is the largest clinico-genetic case series for SCA 12 patients to the best of our knowledge. SCA 12 has variable first symptom at onset. Though tremor in hands is the commonest presenting complaint but there are many other first symptoms. The knowledge of varying presenting features is essential to diagnose the SCA 12 in early disease state.
To cite this abstract in AMA style:
AK. Srivastava, A. Takkar, V. Goyal, F. Mohammad, R. Rajan, A. Garg. Clinico-genetic correlation in 102 Spinocerebellar Ataxia Type 12 (SCA 12) patients [abstract]. Mov Disord. 2019; 34 (suppl 2). https://www.mdsabstracts.org/abstract/clinico-genetic-correlation-in-102-spinocerebellar-ataxia-type-12-sca-12-patients/. Accessed June 15, 2025.« Back to 2019 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/clinico-genetic-correlation-in-102-spinocerebellar-ataxia-type-12-sca-12-patients/