In recent years, the extensive studies of the genetics of disease and health have contributed with substantial knowledge concerning the significance of sequence variations for disease mechanisms, aging and longevity. At the same time, the fast development in molecular genetic laboratory methods has led to an increased interest concerning the functional genomic studies like studies of DNA methylation (i.e. regulation of DNA function) and gene expression (i.e. activity of genes).
DNA methylation is an important part of the so-called epigenetic modifications of the DNA, which plays an important role in the regulation and control of gene activity and which can be influenced by lifestyle and environmental factors.
Since monozygotic twins are genetically identical but not necessarily phenotypically identical, they provide a unique resource for studying the association between different genetic, epigenetic and transcriptional changes and the aging process. In addition, the inheritance of this association can be investigated by inclusion of dizygotic twins.
The focus of the studies is to examine
- the association between variation in the genome, epigenome and transcriptome, and longevity and age-related traits, such as disease incidence, overall health, cognitive and physical function and survival.
- Furthermore, we have a strong interest in age-related changes and gender differences in the epigenome and transcriptome, as well as the complex interplay between the genome, epigenome and transcriptome in relation to aging.
- Finally, we study DNA methylation age, also called 'the epigenetic clock', which are sets of DNA methylation markers that correlate highly to chronological age and for which the difference between chronological age and DNA methylation age has been suggested as a biomarker for aging.
In the studies, we use genetic data (from genome-wide studies of sequence variation), epigenetic data (from genome-wide DNA methylation studies) and transcriptional data (from genome-wide gene expression studies) from middle-aged and older twins who participated in the DaTris and LSADT surveys. These surveys questionnaires and measurements give information regarding a wide range of traits related to health and functional capacity.