Frequencies And Clinical Characters Analysis Of Spinocerebellar Ataxia Subtypes In The Southeastern Chinese Population And Study The Distribution Characters Of The Wild-type CAG Repeats Of ATXN3 With CAG Repeats Ladder Of Self-made In Thousands Chinese Po

Objectives1. To analysis the frequencies of spinocerebellar ataxia subtypes in the Southeastern Chinese population and and study the distribution.2. To analysis the clinical characters of spinocerebellar ataxia subtypes in the Southeastern Chinese population Clinical and and study the distribution.Methods1. Combined polymerase chain reaction with agarose gel electrophoresis or polyacrylamide gel electrophoresis to perform the gene analysis of SCA1, 2, 3, 6, 7, 12, 17 and DRPLA2. Used DNA sequencing to detect the numbers of CAG repeats.Results1. The frequency of SCA3 was 72.5% (100/138) and the frequencies of SCA1, 6, 7 and DRPLA all were 0.7% (1/138), there were no mutations of SCA2, 12 and 17.2. Three families clinically diagnosed as complicated AD-HSP were families of SCA3 confirmed by gene detection.3. One infantile-onset case of SCA7 carried 189 CAG repeats was detected.4. One case of DRPLA carried 63 CAG repeats was detected.Conclusions1. The frequencies of spinocerebellar ataxia subtypes were depend on population and area.2. There was necessity to perform the mutation analysis of ATXN3 in clinically diagnosed complicated AD-HSP patients.3. First reported one Chinese SCA7 family with an infantile-onset case confirmed by molecular analysis and data indicated that duration of life will be longer in infantile-onset cases without multi-organ damage than in cases with multi-organ damage.4. First reported one DRPLA family from Chinese mainland confirmed by molecular analysis. Objectives1. To investigate the difference of reaction efficiency between La Taq and Taq polymerase in amplification of expanded alleles of MJD.2. To prepare a novel CAG repeats ladder as a DNA size marker and to detect resolution of the repeats ladder in PAGE. 3. To detect the relative frequency of Chinese MJD patients in SCA.4. To detect the distribution characters of the wild-type CAG repeats of ATXN3 in wild-type chromosomes of Chinese Han population.5. To study the genotyping and haplotype of the 3 SNPs closely linked to CAG repeats of ATXN3, A669TG/G669TG,C987GG/G987GG and TAA1118/TAC1118.6. To redefine the range of CAG repeats in ATXN3.Methods1. To compare reaction efficiency, 12 MJD patients'expanded alleles were amplified with La Taq and Taq polymerase respectively in the same amplifying systems and reaction conditions.2. CAG repeats ladder was prepared via gene recombination combined with PCR and the resolution of the repeats ladder was detected in PAGE.3. Normal and expanded alleles of ATXN3 were detected via PCR using LA Taq DNA polymerase (better for GC-rich sequences) and denaturing polyacrylamide gel electrophoresis in 138 unrelated probands from SCA families and 1003 unrelated normal individuals from Chinese Han population.4. genotyping and haplotype of the 3 SNPs in 94 normal individuals and 30 MJD patients were detected via allele-specific PCR combined with agarose gel electrophoresis or PAGE and PCR combined with SSCP.Results1. All 12 expanded alleles were amplified in PCR with La Taq polymerase, whereas only 2 expanded alleles were amplified with Taq polymerase.2. The CAG repeats ladder included 32 alleles that contained different CAG repeats numbers and were all resolved clearly in 8% denaturing polyacrylamide gel, the CAG repeats numbers were 13, 14, 18-43, 45, 46, 48 and 49, respectively.3. The frequency of MJD in SCA patients was 72.5%, which was significantly higher than those in previous reports about the Chinese and other Asian populations and was one of the highest reported worldwide, with only Portuguese and Brazilian populations exhibiting higher proportions.4. Normal alleles in 2006 wild-type chromosomes of 1003 individuals ranged from 13 to 49 CAG repeats, and the repeats numbers were 46, 48, 48 and 49 in 4 chromosomes, it first reported that there were intermediate alleles in wild-type chromosomes. The frequency of large normal alleles (>27 repeats) was 0.28, which was the highest relative to previous reports.5. All the expanded alleles had the same haplotype ACA which was significantly higher in large normal alleles than in non-large normal alleles.Conclusions1. The relative frequency of MJD in the Southeastern Chinese population was very high, and we attribute this high frequency to a more efficient PCR using LA Taq polymerase and high frequency of large normal alleles.2. It was accurate, simple, safe and inexpanxive to detect the CAG repeats of ATXN3 via the CAG repeats ladder combined with PAGE.3. Large normal alleles wchic may act as a reservoir for expanded alleles in Chinese Han population were associated with MJD.4. The range of CAG repeats in ATXN3 was redefined as: normal alleles≤44, 45≤intermediate alleles≤49,expanded alleles≥50 CAG repeats.