Genotyping and parental related methylation of SNRPN gene rs220030 / 法医学杂志

OBJECTIVE@#To establish two methods by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing for genotyping rs220030 (a SNP in the promoter region of small nuclear ribonucleoprotein polypeptide N, SNRPN). To establish an analytical technique for detecting CpG methylation status by pyrosequencing and to further investigate the feasibility of applying rs220030 to the determination of parental origin allele.@*METHODS@#The rs220030 of 97 blood samples from individuals of Shanghai Han population were genotyped by DGGE, meanwhile the rs220030 of 25 blood samples of them were genotyped by pyrosequencing to compare the two methods in genotyping SNP. Pyrosequencing united bisulfite conversion method was applied to detect CpG methylation status of region upstream rs220030 of two random blood genealogical samples and investigate whether the methylation status was parental related.@*RESULTS@#The rs220030 genotyping results of 97 blood samples detected by DGGE were 20 C homozygote, 29 T homozygote, and 48 C/T heterozygote. Twenty-five blood samples genotyped by pyrosequencing showed the same result with DGGE. The CpG methylation status of region upstream rs220030 of the child was similar to the mother.@*CONCLUSION@#Compared with DGGE, pyrosequencing is more accurate, convenient, and suitable for large samples and high throughput SNP genotyping. Pyrosequencing united bisulfite conversion can be used to detect CpG methylation status precisely. It is feasible to apply rs220030 to parental origin allele determination.

Polymorphism study of small nuclear ribonucleoprotein polypeptide N gene rs220030 by DGGE / 法医学杂志

OBJECTIVE@#To analyze the polymorphism of rs220030, a SNP which is located in the promoter region of small nuclear ribonucleoprotein polypeptide N (SNRPN) gene in the Chinese Han population and to obtain the data of population genetics.@*METHODS@#The denaturing gradient gel electrophoresis (DGGE) method was applied to detect the polymorphism of rs220030 in 100 unrelated and healthy individuals from the Shanghai Han population. The genotyping result of this SNP was confirmed by TaqMan assay in some typical samples.@*RESULTS@#DGGE results showed 4 bands for CT heterozygote, and 1 band for CC or TT homozygote, and those results were confirmed by The TaqMan SNP genotyping assays. Genotyping results showed 34 individuals with CC, 41 with CT and 25 with TT of rs220030. The allele frequencies for C and T were 0.545 and 0.455, respectively. H was 0.500, PIC was 0.373, DP was 0.654, and PE was 0.186. The distribution of genotype frequencies were in Hardy-Weinberg equilibrium.@*CONCLUSION@#DGGE is a quick and effective method in the analysis of SNP polymorphism in small population. Statistical parameters of rs220030 for forensic evaluation meet the requirements for forensic identification and paternity testing.