A Study Of The Non-ataxia Clinical Symptoms And The Correlation Between The Onset Age And Abnormal Number Of CAG Repetitions In Spinocerebellar Ataxia Type 3

Objective:To study the nonmotor and extracerebellar clinical symptoms in spinocerebellar ataxia type 3(SCA3),by finding out more early nonmotor and extracerebellar symptoms of SCA3,and to study the correlation between CAG abnormal repeat number and the onset age of SCA3,we hope to have a more comprehensive understanding of the natural history of disease.It will help us develop more scientific genetic diagnostic strategies and seize the opportunity of diagnosis and treatment.Thus,appropriate genetic counseling will be provided for the patient's family.Methods:According to the criteria of inclusion and exclusion criteria for SCA3 cases,A total of 47 cases of SCA3 patients with genetic diagnosis in the Neurology Department of the First Affiliated Hospital of China Medical University were collected.The datas of age at onset,family history,clinical manifestations,gene sequencing results and other information were carefully sorted out.We follow up and analyze the natural course of the patients,to explore the clinical symptoms of non-ataxia in patients,to study the correlation between CAG abnormal repeat number and the onset age.The data was statistically analyzed by SPSS 17.0.Results:1.In this study,the age at onset of SCA3 patients ranged from 10 and 56 years old,with an average of 31.94±11.87.The abnormal repetitions of ATXN3 alleles were61-83 times,with an average of 71.83±4.69.2.Based on the date of nonmotor and extracerebellar clinical symptoms of the 47patients,the incidence is higher of ocular symptoms(59.57%),pyramidal tract sign(44.68%),mental symptoms(42.55%),sleep disorders(40.43%)and water choking cough(34.04%).But the rate of cognitive disorders,feeling dysfunction and lumbago is lower(2.13%).3.The study find that the symptoms of non-ataxia,such as eye symptoms(6 cases),extrapyramidal symptoms(2 cases)and bone changes(5 cases),could be the early symptoms of SCA3,prior to the occurrence of ataxia.4.The abnormal CAG repetitions showed a negative correlation with the age of onset.5.The abnormal CAG repetition of SCA3 patients showed a significant effect on AAO(P=0.000),which could explain 73.10%of the change(R~2=0.731).The sex showed no significant influence on AAO(P=0.165).The interaction between sex and abnormal CAG repetitions was also no diffierences for AAO(P=0.168).Conclusion:1.The study find that the symptoms of non-ataxia,such as eye symptoms,extrapyramidal symptoms and bone changes,could be the early symptoms of SCA3,prior to the occurrence of ataxia.2.The non-ataxia clinical symptoms of SCA3 patients are diverse.It can overlap other types of SCAs,even be similar to multiple neurological diseases,presenting a challenge to the diagnosis and differential diagnosis of the disease.3.The onset age of SCA3 patients was negatively correlated with the number of abnormal CAG repetitions.The higher the number of repetitions,the lower the onset age.However,only part variation can be explained in AAO.4.The age of onset of SCA3 patients showed no significant interaction with sex,and the interaction between sex and abnormal CAG repetitions.