Analysis and application of SCA1 and SCA3/MJD gene CAG repeats in Han population in Northeastern China.
- Author:
Miao JIANG
1
;
Chun-lian JIN
;
Chang-kun LIN
;
Guang-rong QIU
;
Zong-lan LIU
;
Chao-xiang WANG
;
Kai-lai SUN
Author Information
- Publication Type:Journal Article
- MeSH: Ataxin-1; Ataxin-3; Ataxins; China; DNA; chemistry; genetics; Family Health; Female; Gene Frequency; Genotype; Humans; Machado-Joseph Disease; diagnosis; genetics; Male; Nerve Tissue Proteins; genetics; Nuclear Proteins; genetics; Pedigree; Repressor Proteins; Sequence Analysis, DNA; Spinocerebellar Ataxias; diagnosis; genetics; Trinucleotide Repeat Expansion; genetics; Trinucleotide Repeats; genetics
- From: Chinese Journal of Medical Genetics 2004;21(1):83-85
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo investigate the normal range of (CAG)n in spinocerebellar ataxia type 1 (SCA1) gene and spinocerebellar ataxia type 3 (SCA3/MJD) gene in 110 normal subjects of Han population in Northeastern China, to assess the genotypes for clinically diagnosed spinocerebellar ataxia(SCA) individuals including 25 patients from 8 families and 6 sporadic patients, and to make presymptomatic and prenatal diagnosis.
METHODSDNA fragments from the normal subjects and the patients were detected by fluorescence-PCR. Homozygosities were selected for DNA sequencing.
RESULTSThe normal ranges of (CAG)n of SCA1 and SCA3/MJD were 20-39 and 14-38 repeats respectively, SCA1 was found mostly to be 26 and 27 repeats, allele frequency 34.09% and 20.91%; heterozygosity was 84.55%, SCA3/MJD was found mostly to be 14 repeats, allele frequency 39.55%, heterozygosity was 78.18%.(CAG)(68) of SCA3/MJD gene of one affected individual had been found in a family but no CAG mutative expansion in related members was observed.
CONCLUSIONThe normal ranges of CAG repeats vary with areas and races. SCAs genotyping is the first choice in presymptomatic and prenatal diagnosis.
