STR Core Facility - our offer
The Swedish Twin Registry, a core facility at Karolinska Institutet, offers opportunities for performing a wide range of twin studies. Our mission is to serve as a longitundinal research resource, facilitating epidemiological and molecular projects involving data of twins.
STR welcomes applications from both Swedish and international researchers. For international researchers, we require collaboration with a Swedish university. To support its operations, STR charges access fees in line with the standard practices of KI core facilities.
Data
Since the 1960s, nationwide questionnaires and telephone interviews have been conducted for various birth cohorts, primarily gathering self-reported health information and exposure data. Additional health and disease information is obtained through linkages with the Swedish health registries. DNA from 50,000 twins and blood serum of 12,000 twins are stored at the KI Biobank and are available for new investigations and analyses. Genome-wide genotyping (GWAS) has been completed over 50,000 participants, with genotypes available for co-analysis of various outcomes and characteristics.
Please note all files are password protected. To obtain the password, contact the Swedish Twin Registry via e-mail at str-research@meb.ki.se.
STR data portal
Metadata from our cohorts and studies is searchable through the STR data portal. These studies cover a range of public health topics, such as allergies, cancer, dementia and cardiovascular disease. Users can create and download customized variable lists of their research interest.
STR data portal
Study Design
Common study designs include classical epidemiological studies to evaluate risk factors for morbidity and mortality, as well as genetic association studies, heritability studies (both classic twin design and molecular-based), epigenetics, proteomics, and other so-called "omics" hypotheses.
Various types of projects
Heritability Studies
By analyzing concordance and discordance rates for diseases amoun identical and fraternal twons, we estimate the relative importance of genetics (heritability) and environmental factors to various diseases and conditions. This can also be done by quantitative measures, like biomarker levels in serum. The corresponding estimate of the importance of genetics can also be molecularly accessed using genome-wide genotyping tests.
Comorbidity Investigation
Bi- and multivariate twin analysis can shed light on why certain diseases are related (comorbidity). Genome-wide genotyping test also aid in exploring this aspect.
Association Within Twin Pairs
Comparing population-level associations with those within twin pairs allows us to measure the genetic contribution to observed association, so-called co-twin control designs.
Discordant Monozygotic Twins
Identical twins sharing the same inherited gene pool provide a unique opportunity to explore environmental factors. Discordant monozygotic twins, where one twin is affected while the other isn't, offer valuable insights into environmental factors like de novo mutations, epigenetics, and levels of metabolites or proteins.
How can we assist?
Advice – Study arrangement and design
- We can share our experience from previous studies.
Feasibility test – Are there twins and data that are of interest to my research question?
- We can investigate the number of pairs with a certain phenotype or exposure.
- Concordance / discordance tables (by zygosity and gender)
- Availability of data / genotypes / sample for these pairs
Data withdrawal – various types of twin data is available
- Self- and parent-reported data from questionnaires and interviews
- Health register data until 2016
Genotypes
- Genome-wide genotyping (GWAS) is available for more than 50,000 twins. Three different Illumina platforms are used, HumanCoreExome (550K), OmniExpress (700K) and Global Screening Array (650K).
- Polygenic risk score (PRS)
Biomarkers and biological surveys (in 12,000 older twins)
- Metabolomics
- Proteomics
- Key blood markers: total cholesterol, HDL, LDL, triglycerides, CRP, glucose, HbA1C, ApoA1, ApoB, hemoglobin, insulin, and pepsinogen
- Blood pressure, height, weight, BMI, waist and hips circumferences
Subscription of questions
- Add your questions to our ongoing studies, if space permits
- Twins aged 9 months, 9, 15, 18 and 24 years old
New contacts – collection of new data
- Selection of twins
- Name and address
Analysis and expertise in twin models
- We can assist with quantitative genetic methodologies such as structural equation models (e.g. OpenMX, SAS, STATA, R)
Fees
| Service | Per | Price |
|---|---|---|
| Searching concordance/discordance over sex and zygosity, availability of data | hour | 900 SEK |
| Application | à | 6,500 SEK |
| Administrative cost for data extraction - new application | à | 25,000 SEK |
| Administrative cost for data extraction - amendment or update of earlier approved application | à | 9,500 SEK |
| Extensive data extractions | hour | 900 SEK |
| DNA sample* | μg | 15 SEK |
| Serum sample* | μg | 15 SEK |
GWAS:
| phenotype | 60,000 SEK |
| Statistical or scientific consultation | hour | 1,200 SEK |
| Addresses and names for new contacts** | address | 15 SEK |
* Depending on availability. The minimum cost per extraction is 25,000 SEK, after that the listed unit price applies. For large extractions, discounts may be discussed. For extractions involving measures in full material that can thereby enrich STR as infrastructure, the cost is determined case by case.
** The minimum cost per project is 10,000 SEK. For projects involving contacts and measures in full-year cohorts and thereby can enrich STR as infrastructure, the cost is determined case by case.