two family with autosomal dominant dementia with cerebellar & extrapyramidal features, and epilepsy

two iranian families with autosomal dominant dementia-plus were observed. one family includes 3 affected members and the other includes 4. the two families showed a dominantly inherited complex neurological syndrome with onset in childhood to adulthood. one patient showed prominent anticipation of the onset age. onset was with cerebellar signs followed by dementia, seizures, and extrapyramidal findings. in both families, magnetic resonance imaging showed marked atrophy of the brain and cerebellum. molecular evaluation of the healthy and affected members of both families by sscp method showed sca17 diagnosis. confirmation of diagnosis by molecular analyses in the tata box-binding protein (tbp) gene (sca17) will be done. early-onset forms of dementia often are caused by genetic factors. significant diagnoses are listed below: • mutations of three different genes (app), (ps-1), (ps-2) have been found in early-onset autosomal dominant forms of ad, • frontotemporal dementia and parkinsonism linked to chromosome 17 (ftdp-17), • hd, • huntingtons disease (hd)-likes (prnp), • dentatorubro-pallidoluysian atrophy (drpla), • spinocerebellar ataxias (sca), • familial parkinsonism (park1, park2, park3) • all types of scas