The Danish Twin Register

The aim of the register

The Danish Twin Register (DTR) is one of the world’s oldest twin registers. It was established in the 1950s to study the causes of cancer. Over the following half century, the register was expanded and now includes twin births from over the past 125 years. Medical research continues to be the key aspect for the many Danish and foreign researchers affiliated with the register.

Responsible authority

University of Southern Denmark

Tel.: +45 65 50 30 47. Fax.: +45 65 90 69 38.


Researchers who are not affiliated with the register can obtain information about the use of the register upon request.


1870-1930: 19,000 pairs
1931-1952: 17,000 pairs
1953-1982: 20,000 pairs
1983-1996: 11,000 pairs
Boy/girl twin pairs:
1870-1910 and 1931-1996: Yes
1911-1930: No


Statistical master data from church records and the Danish Civil Registration System. Information on health and lifestyle. Information on causes of death.


The register is updated via questionnaire-based studies, interviews and clinical studies.


1870-1930: Information from church records
1931-1982: The Danish Civil Registration System
1983-1996: The Medical Birth Register.

Period covered

1870-2000 for the entire country.


Brix, T.H., Hansen, P.S., Kyvik, K.O, Hegedus, L. (2000): Cigarette smoking and risk of clinically overt thyroid disease: a population-based twin case control study. Archive of Internal Medicine, 160:661-666.
Chistensen, K., Kristiansen, M., Hagen-Larsen, H., Skytthe, A., Bathum, L., Jeune, B., Andersen-Ranberg, K., Vaupel, J.W., Ørstavik, K.H. (2000): X-linked genetic factors regulate hematopoietic stem-cell kinetics in females. Blood, 95: 2449-5451.
Christensen, K., Vaupel, J.W., Holm, N.V., Yashin, A.I. (1995): Mortality among twins after age 6: fetal origins hypothesis versus twin method. BMJ, 310(6977), 432-436.
Herskind, A.M., McGue, M., Holm N.V., Sørensen, T.I., Harvald, B., Vaupel, J.W. (1996): The heritability of human longevity: a population-based study of 2872 Danish twin pairs born 1870-7900. Human Genetics, 97:319-323.
Kyvik, K.O., Christensen, K., Skytthe, A., Harvald, B., Holm, N.V. (1996): The Danish Twin Register. Danish Medical Bulletin, 43:467-470.
An expanded list of publications can be requested.