A study on the application of methylation-microhaplotypes in the identification of synthetic human DNA samples
- VernacularTitle:甲基化-微单倍型在伪造人体DNA样本鉴识中的应用研究
- Author:
Yue WANG
1
;
Dan WEN
1
;
Xuan TANG
1
;
Yi LIU
1
;
Ruyi XU
1
;
Siqi CHEN
1
;
Xiaoyi FU
1
;
Xue LI
1
;
Yuepeng WANG
1
;
Chudong WANG
1
;
Weifeng QU
1
;
Hongtao JIA
1
;
Jienan LI
1
;
Lagabaiyila ZHA
1
Author Information
- Publication Type:Journal Article
- Keywords: Forensic medicine; Personal identification; Methylation-microhaplotype; Human DNA; Synthetic DNA
- From: Chinese Journal of Forensic Medicine 2025;40(1):40-48,55
- CountryChina
- Language:Chinese
- Abstract: Objective Advances in synthetic DNA technology have made it much easier to fake human DNA samples.There are literature reports that fake human DNA can be synthesized by different methods and implanted in the field to confuse the investigation or mislead the trial.Therefore,distinguishing authentic human DNA from synthetic DNA and performing individual identification has become a critical scientific challenge.Methods We define a novel composite genetic marker(methylation-microhaplotype)by combining CpG sites stably hypermethylated or hypomethylated in natural human DNA and nearby immediately adjacent microhaplotype sites.A total of 19 locis were obtained according to the screening criteria,and a composite detection system for methylation-microhaplotypes was established using MPS technology.Random volunteer DNA samples were extracted and synthetic DNA samples were prepared based on whole genome amplification techniques.Population DNA samples were analyzed to evaluate forensic parameters and methylation variability of the methylation-microhaplotype markers.Comparative analyses of human and synthetic DNA were conducted to assess the markers'ability to discriminate between the two and to detect/type both components in mixed mixed samples.Results The composite detection system composed of 19 locis demonstrated high individual identification ability,achieving a cumulative individual identification probability of 0.999 999 999 996 86.12 hypermethylated locis and 7 hypomethylated locis had relatively stable methylation levels in 57 human DNA samples.According to the allele methylation rate(Ram)value,the system can effectively identify natural and synthetic DNA samples.Meanwhile,for mixed DNA samples,the presence of human and synthetic DNA samples can be found and genotyped.Conclusion Methylation-microhaplotype genetic markers,which can discover human DNA and synthetic DNA and can detect the presence and genotyping of them from mixed samples,is a potential useful tool for forensic DNA analysis.
