Genetic and clinical analysis in a Parkinson's disease family caused by expansion of SCA2 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the clinical and genetic features of a family with Parkinson's disease caused by expansion of CAG triplet repeat in the ATXN2 gene.</p><p><b>METHODS</b>The CAG/CAA repeat in the ATXN2 gene was analyzed by polymerase chain reaction (PCR) and Sanger sequencing.</p><p><b>RESULTS</b>Molecular testing has documented a pathological heterozygous expansion of the CAG repeat from 33 to 35 in 6 patients and other 8 family members. Two patients had pure CAG triplet repeat expansion in their ATXN2 gene, while others had CAA interruption.</p><p><b>CONCLUSION</b>Expanded CAG/CAA repeat in the ATXN2 gene is the causative mutation of the disease in this family.The 8 members with expanded CAG/CAA repeat may be asymptomatic patients. It is supposed that the number and configuration of the ATXN2 CAG/CAA repeat expansion may play an important role in the phenotypic variability of Parkinson's disease.</p>

Mutation analysis of DJ-1 in patients with early-onset Parkinson's disease and relationship between the g.168_185del polymorphism and Parkinson's disease / 中华神经科杂志

Objective To evaluate the prevalence of the DJ-1 mutation in early-onset Parkinson's disease (EOPD) patients,and analyzed the association between the certain polymorphic marker g.168_185del in intron1 and Parkinson' s disease (PD).Methods We screened all 7 exons and exon-intron boundary regions of DJ-1 by PCR and direct nucleotide sequencing in 90 Chinese patients with EOPD.We also compared the allele and genotype frequencies of the g.168_185del polymorphism between EOPD patients and controls.Results We found no causative DJ-1 mutations in our cohort of Chinese EOPD patients.But we did identified 4 known polymorphic variants,including the g.168_185del in intron 1,g.5027G ＞ A (rs17523802),g.5065T ＞ C (rs226249),and g.5094C ＞ T (rs11121064) within exon 1.Del/Ins frequencies of the g.168_185 del polymorphism were 11.1％ (10/90)and 13.3％ (14/105) in EOPD group and normal group,respectively.Ins/Ins frequencies were 88.9％ (80/90) and 86.7％ (91/105),thex2 and P value of genotype frequency were 0.222 and 0.669 between EOPD patients and controls,respectively.The insert frequencies were 94.4％ (170/180)and 93.3％ (196/210) in EOPD patients and controls,the deletion frequencies were 5.6％ (10/180) and 6.7％ (14/210),thex2 and P value of allele frequency were 0.207 and 0.679 between EOPD patients and normal,respectively.Furthermore,the P value of genotype and allele frequencies were 0.736 and 0.744 between familial EOPD patients and controls,respectively;P values of genotype and allele frequencies were 0.847 and 0.852 between sporadic EOPD patients and control group,respectively.There was no statistical difference between groups.Conclusion Mutations in DJ-1 are uncommon in Chinese EOPD patients,and no association is observed between the DJ-1 intron 1 g.168_185del polymorphism and risk of PD.