Breaking News
March 23, 2018 - Wales participates in the 100,000 Genomes Project
March 23, 2018 - 24-Hr Paging Cuts ED Visits for Kids with Endocrine Issues
March 23, 2018 - The brain learns completely differently than we’ve assumed since the 20th century
March 23, 2018 - Less nutritious diet mainly contributes to Type 2 diabetes among U.S.-based South Asians
March 23, 2018 - Stony Brook Medicine expert provides tips for healthy diet to decrease cancer risk
March 23, 2018 - New findings could have revolutionary impact on quality of life of older people
March 23, 2018 - Restoring enzyme may help reverse effects of vascular aging, study shows
March 23, 2018 - Protein profiling reveals new prostate cancer mechanisms
March 23, 2018 - FDA Takes Aim at Flavored Tobacco
March 23, 2018 - SMART Strategy Lowers Asthma Exacerbation Risk
March 23, 2018 - Cold open water plunge provides instant pain relief
March 23, 2018 - Patients with vascular malformations have poor health-related quality of life
March 23, 2018 - New DOD grant to support testing of promising therapy for triple-negative breast cancer
March 23, 2018 - Novel vaccine technologies can help better prepare for future infectious disease threats
March 23, 2018 - OncoBreak: Colonoscopy TV; Coverage for Genomic Testing; Care for Caregivers
March 23, 2018 - For some surgeries, nerve blocks mean better outcomes, fewer opioids
March 23, 2018 - Maternal obesity and androgen excess induce sex-specific anxiety in offspring, study suggests
March 23, 2018 - The tale of Theranos and the mysterious fire alarm
March 23, 2018 - USC researchers create algorithm to optimize substance abuse intervention groups
March 23, 2018 - Impulsivity may be associated with greater weight loss during treatment in obese children
March 23, 2018 - CTI BioPharma Announces Publication of Pacritinib Phase 3 PERSIST-2 Clinical Trial in JAMA Oncology
March 23, 2018 - Senate Panel Addresses Native Americans’ Opioid Troubles
March 23, 2018 - Brain connections in schizophrenia
March 23, 2018 - Mental health assessment in health checks can help detect psychologically vulnerable people
March 23, 2018 - New test for urothelial cancers offers less invasive, more accurate detection
March 23, 2018 - Groundbreaking 100,000 Genomes Project achieves important milestone to transform NHS care
March 23, 2018 - Mice getting a new lease of life with anti-aging pills
March 23, 2018 - Obesity kills taste buds and dulls taste sensation finds study
March 23, 2018 - Medical students get less formal education in radiation oncology, study finds
March 23, 2018 - Researchers find investigational compound to treat triple negative breast cancer after brain metastasis
March 23, 2018 - Researchers develop wearable system to monitor electrical activity in the stomach over 24 hours
March 23, 2018 - A Different Opioid Crisis | Medpage Today
March 23, 2018 - PTSD an ongoing fight for generation of Iraq War vets
March 23, 2018 - Researchers uncover specific gene region in hypertension
March 23, 2018 - Specific immune cells may help slow progression of ALS, research shows
March 23, 2018 - Biosense Webster launches new ‘Power to Heal’ campaign to alleviate AF burden
March 23, 2018 - FDA could curb or ban tobacco in menthol or fruit flavoured cigarettes soon
March 23, 2018 - Mom’s Pre-Pregnancy Waist Size Tied to Autism Risk
March 23, 2018 - AMD Treat-and-Extend Regimens OK: Ophthalmology Times
March 23, 2018 - Safe-sleep recommendations for infants have not reduced sudden deaths in newborns
March 23, 2018 - Survey finds inappropriate prescribing of antibiotics for hospitalized children
March 23, 2018 - Researchers propose alternative treatment to target lymphoma signaling at its root
March 22, 2018 - Compound found in beet extract could help slow progression of Alzheimer’s disease
March 22, 2018 - Lower temperatures can trigger the body’s ‘good’ fat formation at cellular level
March 22, 2018 - Sentinel lymph node biopsies could be safely avoided for some breast cancer patients
March 22, 2018 - Combined Preeclampsia Test Superior to U.K. Standards
March 22, 2018 - Exclusive breastfeeding in hospital associated with longer breastfeeding duration
March 22, 2018 - Researchers prove link between common childhood cancer and inflammation
March 22, 2018 - Targeting aberrantly active telomerase to treat therapy-resistant melanoma
March 22, 2018 - California’s tax on millionaires yields big benefits for people with mental illness, study finds
March 22, 2018 - Weight-loss surgery reduces risk for severe chronic kidney disease and kidney failure
March 22, 2018 - Study identifies two genes associated with extreme nausea and vomiting during pregnancy
March 22, 2018 - Biohaven Enrolls First Patient In Phase 3 Clinical Trial To Evaluate Rimegepant Zydis® ODT In The Acute Treatment Of Migraine
March 22, 2018 - ‘Bionic Pancreas’ OK for Very Young T1D Patients
March 22, 2018 - Parkinson’s gene initiates disease outside of the brain
March 22, 2018 - NMSU researchers publish findings on effective measures to remedy stress among adolescents
March 22, 2018 - Immunotherapy combination increases overall survival in people with kidney cancer, study shows
March 22, 2018 - Increased rate of accidental injuries associated with poorer hearing ability
March 22, 2018 - Gut microbiome may promote pancreatic cancer by inducing immune suppression
March 22, 2018 - New ocular inserts allow patient’s cornea to absorb more antibiotics
March 22, 2018 - FDA Alert: NeuroBlate Probe by Monteris Medical: Letter to Health Care Providers, Class I Recall
March 22, 2018 - Cessation of exercise can result in increased depressive symptoms
March 22, 2018 - Morning Break: Booze Study Brouhaha; Stem Cells for MS; Big Debt Problem
March 22, 2018 - New wearable tech from Western may hold big benefits for people with Parkinson’s
March 22, 2018 - Immune cells can repopulate in the retina after elimination, mice study shows
March 22, 2018 - States extend Medicaid for birth control, cutting costs — and future enrollment
March 22, 2018 - Research provides better understanding of how cancerous cells behave in low oxygen
March 22, 2018 - Menopausal hormone therapy taken soon after menopause may benefit the brain
March 22, 2018 - Booze Boosts Your Heart Rate
March 22, 2018 - Skeptical Cardiologist: Classifying Heart Failure
March 22, 2018 - Instead of nagging your spouse to lose weight, try going on a diet yourself
March 22, 2018 - Neem Biotech to share findings on cystic fibrosis biofilm disruption at ECFS Basic Science Conference
March 22, 2018 - Study uncovers new genetic cause of posterior polymorphous corneal dystrophy
March 22, 2018 - ENDO: Big Breakfast May Help in Diabetics
March 22, 2018 - I’m not overweight, so why do I need to eat healthy foods?
March 22, 2018 - UCLA-led study suggests unexpected reason for reduction in cardiovascular health disparities
March 22, 2018 - Study suggests detailed neuropsychological assessment for brief cardiac arrest survivors
March 22, 2018 - Anticoagulant drugs found safe to use in patients undergoing surgery for irregular heartbeat
March 22, 2018 - SP Industries appoints Brian Larkin as new President and CEO
March 22, 2018 - GTx Announced New Data Demonstrating Enobosarm’s Potential to Treat Stress Urinary Incontinence
Identical twins share additional level of molecular similarity

Identical twins share additional level of molecular similarity

image_pdfDownload PDFimage_print

An international group of researchers has discovered a new phenomenon that occurs in identical twins: independent of their identical genes, they share an additional level of molecular similarity that influences their biological characteristics. The researchers propose a mechanism to explain the extra level of similarity and show that it is associated with risk of cancer in adulthood. The results appear in the journal Genome Biology.

“The characteristics of an individual depend not only on genes inherited from the parents but also on epigenetics, which refers to molecular mechanisms that determine which genes will be turned on or off in different cell types. If we view one’s DNA as the computer hardware, epigenetics is the software that determines what the computer can do,” said senior author Dr. Robert A. Waterland, associate professor of pediatrics – nutrition at the USDA/ARS Children’s Nutrition Research Center and Texas Children’s Hospital and of molecular and human genetics at Baylor College of Medicine.

Epigenetics works by adding or removing chemical tags to genes to mark which ones should be used in different cell types. One of the better studied tags, known to play an important role in development and cancer, is the methyl chemical group. Here, in a large group of identical and fraternal twin pairs, Waterland and his colleagues studied a group of genes called metastable epialleles. Previous work indicated that methyl tags are randomly added to metastable epialleles during early embryonic development and maintained throughout life.

“We expected that the patterns of methyl tags added to metastable epialleles would be equally random in identical twins and fraternal twins,” Waterland said. “Instead, we found that the methylation patterns matched almost perfectly in identical twins, a degree of similarity that could not be explained by the twins sharing the same DNA. We call this phenomenon ‘epigenetic supersimilarity.'”

Identical twins are formed when the very early embryo – essentially a ball of cells – splits into two parts, and each continues to develop into a separate human being. The authors proposed and tested a simple model to explain epigenetic supersimilarity.

“If, in this group of genes, the epigenetic markers are established before the embryo splits into two, then the markers will be the same in both twins,” Waterland said. “In essence, both twins inherit an intimate molecular memory of their shared developmental legacy as a single individual. On the other hand, genes at which epigenetic markers are set after the embryo splits can have greater epigenetic differences between the two twins.”

Cancer connection

Epigenetic supersimilarity seems to occur in a relatively small group of genes, but, as the researchers discovered, many of these are associated with cancer. To test whether these epigenetic markers might affect risk of cancer, the scientists in Houston teamed up with cancer epidemiologists running the Cancer Council Victoria’s Melbourne Collaborative Cohort Study in Melbourne, Australia. Back in the 1990s, this large study was set up to assess different risk factors for cancer.

“By analyzing peripheral blood DNA samples from healthy adults in our study, we have been able to show that methylation at epigenetically supersimilar genes is associated with risk of subsequently developing several types of cancer, including lung, prostate and colorectal cancer,” said Dr. Roger Milne, associate professor and head of Cancer Epidemiology at Cancer Council Victoria, and an author on the study.

This study shows that, at the epigenetic level, identical twins are more similar to each other than previously recognized.

“Our findings should prompt a re-evaluation of previous genetic studies on twins,” Waterland said. “For decades, researchers have studied genetically identical twins to estimate what proportion of disease risk is determined by one’s genes. To the extent that epigenetic supersimilarity affects risk of disease, as our results indicate, genetic risk estimates based on twin studies have been inflated.”

Tagged with:

About author

Related Articles