Category Archives: For Twins

DNA methylation associated with healthy aging of elderly twins.

Kim S, Wyckoff J, Morris AT, Succop A, Avery A, Duncan GE, Michal Jazwinski S.

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Gene Expression and the Microbiome in Twins (GEMsTone)

Cells in the human body contain DNA. Each cell expresses, or turns on, a fraction of its genes in a process known as gene regulation. Genes can be expressed depending on your genetic history, your lifestyle, and your environment. Microbes are very small life forms such as bacteria that exist on or in the human body. The human microbiome is the full collection of genes of all of the microbes. In this study, we are interested in learning more about the relationship between your genes and your microbiome. The gut microbiome changes over time, but can also change when your diet changes or when your health in general changes. As a twin and a member of the WSTR, you can make a unique contribution to understanding the relationship between the gut microbiome and gene expression.

Eligible twin pairs are sent the collection materials to collect data at home. Data collection materials include three questionnaires, measuring waist circumference, using a soft brush to collect buccal (cheek) cells for epigenetic analysis, and collecting a stool sample for the gut microbiome analysis.

Twin Breast Cancer Study

Dr. Thomas Mack of the USC California Twin Program is reaching out to twins diagnosed with breast cancer in order to understand why some women remain free from breast cancer when other women with the same genetics and upbringing are affected.

What we know:
  • As a group, twin women of any age, including identical twin women, are at the same risk of breast cancer as their friends and neighbors.
  • Even though inheritance seems to play at least some role in most cases of breast cancer, most of the healthy co-twins of women who are diagnosed with breast cancer remain free, for years, decades or permanently.
  • That suggests that some causal elements are acquired, probably long before the appearance of the disease, possibly as early as childhood.
What does the study entail?

We will ask each participant to provide a sample of saliva. From such samples we can find cells containing the unique inherited DNA code and identify any genetic breast cancer risk factors.

What questions will be asked?
  1. Generally: Participants will be asked questions relating to known predictors of breast cancer risk, most of which relate to reproductive history.
  2. Twin comparisons: Twins have compared each other since childhood, and are uniquely able to recall and agree on early differences, even after decades. Questions will be especially directed at early differences.
  3. We will ask breast cancer cases to help us obtain Pathology Reports and samples of tumor tissue from providers.

The questions should take you one-half to one hour. The more twins who participate, especially as pairs, the more likely that we can find answers to these important questions about a dreaded disease.

The study is supported by the National Cancer Institute of the National Institutes of Health. There is no cost to volunteers, except the time it takes to mark your responses and send your specimen. You will never be asked for money (your cooperation is more valuable). You may always refuse to answer any question, and you may withdraw cooperation at any time. All information will be held in complete confidence. No outside persons will have access to your identity without your permission. Results will only be released in statistical form, and no persons will ever be identified.


Click here to send an email to the study coordinator. If you would prefer to speak to someone by phone, please call 1-323-865-0828.

FTO genotype impacts food intake and corticolimbic activation.

Melhorn SJ, Askren MK, Chung WK, Kratz M, Bosch TA, Tyagi V, Webb MF, De Leon MRB, Grabowski TJ, Leibel RL, Schur EA.

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Examination of Cross-Sectional Associations of Neighborhood Deprivation and Alcohol Outlet Density With Hazardous Drinking Using a Twin Design.

Rhew IC, Kosterman R, Duncan GE, Mair C.

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Education in Twins and Their Parents Across Birth Cohorts Over 100 years: An Individual-Level Pooled Analysis of 42-Twin Cohorts.

Silventoinen K, Jelenkovic A, Hopper JL, Busjahn A, Cozen W, Mack TM, Sumathipala A, Harris JR, Goldberg JH, Harden KP, Duncan GE, Buchwald D, Turkheimer E, Kaprio J, et al.

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Cross-sectional association between soda consumption and body mass index in a community-based sample of twins.

Eney AE, Tsang S, Delaney JA, Turkheimer E, Duncan GE.

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Differences in genetic and environmental variation in adult body mass index by sex, age, time period, and region: an individual-based pooled analysis of 40 twin cohorts.

Silventoinen K, Jelenkovic A, Cozen W, Mack T, Sumathipala A, Christensen K, Busjahn A, Duncan GE, Buchwald D, Goldberg JH, Hopper JL, Sung J, Turkheimer E, Kaprio J, et al.

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Genetic and Environment Influences on Sleep, Pain, and Depression Symptoms in a Community Sample of Twins.

Gasperi M, Herbert M, Schur E, Buchwald D, Afari N.

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Neighborhood walkability moderates the association between low back pain and physical activity: A co-twin control study.

Zadro JR, Shirley D, Pinheiro MB, Bauman A, Duncan GE, Ferreira PH.

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Does the sex of one’s co-twin affect height and BMI in adulthood? A study of dizygotic adult twins from 31 cohorts.

Bogl LH, Jelenkovic A, Christensen K, Cozen W, Mack TM, Duncan GE, Buchwald D, Hopper JL, Silventoinen K, Kaprio J, et al.

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Neighborhood deprivation and depression in adult twins: genetics and gene×environment interaction.

Strachan E, Duncan G, Horn E, Turkheimer E.

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Transcriptional Signatures of Sleep Duration Discordance in Monozygotic Twins.

Watson NF, Buchwald D, Delrow JJ, Altemeier WA, Vitiello MV, Pack AI, Bamshad M, Noonan C, Gharib S.

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