Clinical features and genetic mutation analysis of spinocerebellar ataxias in Yunnan region / 中华神经科杂志

ABSTRACT

Objective To identify the specific genotype and analyze clinical features of spinocerebellar ataxias (SCAs) pedigree in the region of Yunnan Province.Methods Fourteen SCAs pedigrees and 183 blood samples of the family members were collected between January 2011 and July 2014 from Department of Neurology,First Affiliated Hospital of Kunming Medical College.Polymerase chain reaction (PCR) amplification,agarose gel electrophoresis and DNA sequencing technologies were utilized to identify the specific genotype of SCAs pedigree.Presymptomatic tests were carried out and the clinical features and genetic test results of patients were carefully analyzed.Results SCA3 was the most common subtype of SCAs in the Han nationality of Yunnan region.Nine of the 14 families were SCA3,only one family was SCA2.Additionally,there were four SCAs families that remained indeterminate.The patients with di-allele mutations (46/77) of SCA3 gene had early onset,rapid progression and serious clinical symptoms.Hereditary SCA3 and autonomic dominant polycystic kidney disease can happen simultaneously in a family.The proband SCA3 gene' s CAG repeat number is 28/76,and repetitions of the mutation allele are in all range.The PKD1 gene exon 23 is found to be in abnormal sequence.Conclusions SCA3 is the most common subtype of SCAs in the Han population of Yunnan region.There are 15/46 incomplete penetrance nutation and 46/77 di-allele mutations.It is possible that di-allele mutations make the disease worse and accelerate clinical course progression.SCA3 and polycystic kidney disease can uncommonly happen simultaneously in a family,which perhaps suggests there are interactions between the two disease-virulence genes.