ABSTRACT
Objective To study the clinic, neuro electrophysiology and molecular biology of Machado Joseph disease (MJD).Methods Family visiting, physical examination and the blood samples were analysed on molecular biology in 44 members of a family with MJD.The cases of inpatients were examined on cerebrospinal fluid and neuro electrophysiology.Results 10 patients of the family attacked,which were consisted with autosomal dominant inheritance type. Age of the onset was 8~38 years old. The clinical characteristic was progressive severe spinocerebellar of ataxia,faciolingual myokymia,bulging eyes.Change of denervated muscle was revealed by neuro etectrophysiological examination. Light atrophy was observed in cerebellar,brain stem, spinal cord.The genetic defect of MJD was located the long arm of chromosome 14 between D 14 S 280 and D 14 S 81 , their distance was 3.0 cm.All tested patients had their CAG repeated expansion from 72 to 84 in the MJD gene.Conclusion MJD is a neuro degenerative disorder of autosomal dominant inheritance. The disease was clinically characterized by progressive severe spinocerebellar ataxia, no obvious changes of cerebrospinal fluid,neuro electrophysiology, CT and MRI.The genetic defect of MJD was located the long arm of chromosome 14.The number of CAG repeated expansion mutation was associated with the age of the onset.