Clinical and molecular biological characteristics of spinocerebellar ataxia type 3 / 临床神经病学杂志

ABSTRACT

Objective To explore the clinical and molecular biological characteristics of spinocerebellar ataxia type 3(SCA3).Methods Clinical manifestation and brain MRI data of 12 patients with SCA in two families were analyged.The polymorphic CAG repeated time in the encode region of SCA3,SCA1 and SCA7 genes were compared in 15 family numbers without abnormal presentations,and 12 healthy persons of controls.Results Among 27 numbers of 4 generations in the two families had 12 patients,male and female were affected,average onset was 32 years old.The main clinic features included gait ataxia,ambiguity in speech and action clumsiness.Brain MRI showed remarkable atrophy on cerebellum and brain stem.In the two families,the CAG lengths of SCA1 and SCA7 were normal in all numbers.The repeated times of CAG of SCA3 were 11~39 in two control groups,65 ~87 in 10 cases,diagnosed as SCA3 patients.The child Ⅳ2 of family 1 was 8 years old,the repeated times of CAG of SCA3 were repeats 21 and 64 times,repectively.He might be a asymptomatic patient,because he was too young to onset the disease.Conclusions SCA3 is an autosomal dominant genetic disease.The clinical manifestations are ataxia and dysarthria.The detection of repeated times CAG can provide an effective way for the genetic and asymptomatic diagnosis.