Clinical assessment of a patient with spinocerebellar ataxia

In the case of spinocerebellar ataxia (SCA) we are dealing with a disease entity that today is based on recent and ongoing genetic findings. We now distinguish more than 20 SCA subtypes with distinct gene loci. These genetic SCA subtypes allow classification based on genetic findings in approximately 60% to 80% of ADCA families. In single families with other neurological disorders as a leading symptom and autosomal inheritance, e.g. familial parkinsonism, a genetic diagnosis of SCA could be established (Giunti, 1995). Vice versa, with genetic testing becoming more and more available, approximately 12% of cases with sporadic ataxia of adult onset ( i.e. without family history suggestive of autosomal-dominant trait) have been defined as carriers of SCA mutations (Abele, 2002, Schöls, 2000). Nevertheless, there remain several families suggestive of ADCA with as yet unidentified genetic cause.