Twin Study

The Twin study, coordinated by the University of Helsinki, is a large research collection of data and samples from Finnish twins. The Twin study cohort consist of longitudinal data collected by questionnaires and interviews, done in minimum of four waves covering over three decades, and data and samples collected during several sub-studies.

The twin study cohort consists of the older and two younger cohort data collections.

The older twin cohort includes twin pairs born before 1958. Questionnaire and interview data collection of the older twin cohort were performed in three waves in 1975, 1981 and 1990. The fourth wave data collection was conducted in three separate sub-studies by year of birth, and was therefore performed over two decades (1999-2012).

The younger twin research cohort consists of two main studies, FinnTwin12 and FinnTwin16.

FinnTwin12 study was established in 1994 to examine genetic and environmental determinants of health-related behavior in young twins, born in 1983-1987. The first questionnaires were sent to children at the age of 11-12 years (and their families) followed by three other waves of data collection at ages of 14, 17½ and 22.

Finntwin16 is a follow-up study of Finnish twins born in 1974–1979 including their parents. The study started between 1991 and 1995 when the first questionnaires were sent to 16 years old twins. The follow-ups were done for the twins were 17, 18½, about 24 and about 35 years old.

Samples and data available in THL Biobank

DNA samples, height and weight of more than 14 000 participants of the Twin study are available for research purposes through THL Biobank. For more detailed sample information, please see the 'THL Biobank Sample availability table'.

Genome-wide SNP data is available for majority of the study participants, for more detailed information, please see the 'THL Biobank Omics availability table'.