Disease Information for Dominant SCA/Spinal Cerebellar ataxias: Definition

  • Dominant hereditary spinal cerebellar ataxia syndromes; now number 1 to 25 types according to genetic gene loci and mutations; usually run true in family cohorts; much overlap on classifying clinically; most have dysarthria and ataxia with early or late spasticity; onset in 3rd decade; extrapyramidal, ocular, and peripheral neuropathy, seizures and intellectual deterioration occur in these progressive

    neurodegenerative disorders; [machado-joseph; friedrichs, roussey-levy, pelizaeus-merzbacher, olivopontinecerebellar, cuba, mexican, brazil, japanese, dutch, german variants; also formerly ADCA I,II,III]--------------------------------------------------------

    Ataxia, Hereditary, Autosomal Dominant; Dentato-Rubro-Pallido-Luysian Atrophy; Episodic Ataxia; Progressive Cerebellar Ataxia, Familial; SCA; Spinocerebellar Ataxia;

    Disorder Subdivisions: Marie"s Ataxia;

    The hereditary ataxias are a group of neurological disorders (ataxias) of varying degrees of rarity that are inherited, in contrast to a related group of neurological disorders that are acquired through accidents, injuries, or other external agents; The hereditary ataxias are characterized by degenerative changes in the brain and spinal cord that lead to an awkward, uncoordinated walk (gait) accompanied often by poor eye-hand coordination and abnormal speech (dysarthria); Hereditary ataxia in one or another of its forms may present at almost any time between infancy and adulthood; The classification of hereditary ataxias is complex [University of Washington’s classification]; This classification is based on the pattern of inheritance or mode of genetic transmission of the disorder: ie, autosomal dominant, autosomal recessive and X-linked; The autosomal dominant ataxias, also called the spinocerebellar ataxias, are usually identified as SCA1 through SCA25; Also included are several "episodic ataxias", as well as a very rare disorder known as DRPLA (dentato-rubro-pallido-luysian atrophy); This report deals with the autosomal dominant hereditary ataxias; There are fewer autosomal recessive hereditary ataxias than autosomal dominant hereditary ataxias, and X-linked forms of ataxia are very rare; Until recently, all autosomal dominant ataxias were called Marie’s ataxia and all autosomal recessive ataxias were called Friedreich’s ataxia-------------[NORD 2005]-------------------------------------------

    autosomal dominant cerebellar ataxia; This is a heterogeneous group of adult-onset progressive ataxias which have an autosomal dominant mode of inheritance; There is often a widespread neuronal degeneration which resembles multiple system atrophy; There are three main clinical groups: spinocerebellar ataxia type 1, spinocerebellar ataxia type 2, Machado-Joseph syndrome or cerebellar cortical degeneration-------[gpnotebook_com 2005]-----