Ethnicity, age and disease-associated variation in body fluid-specific CpG sites in a diverse South African cohort.
Forensic Sci Int
; 314: 110372, 2020 Sep.
Article
de En
| MEDLINE
| ID: mdl-32623090
ABSTRACT
Tissue-specific differential DNA methylation has been an attractive target for the development of markers for discrimination of body fluids found at crime scenes. Though mostly stable, DNA methylation patterns have been shown to vary between different ethnic groups, in different age groups as well as between healthy and diseased individuals. To the best of our knowledge, none of the markers for body fluid identification have been applied to different ethnic groups to ascertain if variability exists. In the present study, saliva and blood were collected to determine the effects of ethnicity (Blacks, Whites, Coloureds and Indians), age (20-30 years, 40-50years and above 60 years) and diabetes on methylation profiles of potential saliva- and blood-specific DMSs. Both DMSs were previously shown to exhibit hypermethylation in their target body fluids at single CpG sites, however in the present study, additional CpG sites flanking the reported sites were also screened. Bisulfite sequencing revealed that Coloureds showed highest methylation levels for both body fluids, and blacks displayed significant differences between other ethnic groups in the blood-specific CpG sites. A decline in methylation for both potential DMRs was observed with increasing age. Heavily methylated CpG sites in different ethnic groups and previously reported DMSs displayed hypomethylation with increasing age and disease status. Diabetic status did not show any significant difference in methylation when compared to healthy counterparts. Thus, the use of methylation markers for forensics needs thorough investigation of influence of external factors and ideally, several CpG sites should be co-analysed instead of a single DMS.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Salive
/
Analyse chimique du sang
/
Ilots CpG
/
Méthylation de l'ADN
Type d'étude:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Aspects:
Determinantes_sociais_saude
Limites:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Pays/Région comme sujet:
Africa
Langue:
En
Journal:
Forensic Sci Int
Année:
2020
Type de document:
Article