Rethinking the genetic theory of inheritanceJanuary 20, 2009Scientists at the Centre for Addiction and Mental Health (CAMH) have detected evidence that DNA may not be the only carrier of heritable information; a secondary molecular mechanism called epigenetics may also account for some inherited traits and diseases. These findings challenge the fundamental principles of genetics and inheritance, and potentially provide a new insight into the primary causes of human diseases. Your mother's eyes, your father's height, your predisposition to disease-- these are traits inherited from your parents. Traditionally, 'heritability' is estimated by comparing monozygotic (genetically identical) twins to dizygotic (genetically different) twins. A trait or disease is called heritable if monozygotic twins are more similar to each other than dizygotic twins. In molecular terms, heritability has traditionally been attributed to variations in the DNA sequence. CAMH's Dr. Art Petronis, head of the Krembil Family Epigenetics Laboratory, and his team conducted a comprehensive epigenetic analysis of 100 sets of monozygotic and dizygotic twins in the first study of its kind. Said Dr. Petronis, "We investigated molecules that attach to DNA and regulate various gene activities. These DNA modifications are called epigenetic factors." The CAMH study showed that epigenetic factors - acting independently from DNA - were more similar in monozygotic twins than dizygotic twins. This finding suggests that there is a secondary molecular mechanism of heredity. The epigenetic heritability may help explain currently unclear issues in human disease, such as the presence of a disease in only one monozygotic twin, the different susceptibility of males (e.g. to autism) and females (e.g. to lupus), significant fluctuations in the course of a disease (e.g. bipolar disorder, inflammatory bowel disease, multiple sclerosis), among numerous others. "Traditionally, it has been assumed that only the DNA sequence can account for the capability of normal traits and diseases to be inherited," says Dr. Petronis. "Over the last several decades, there has been an enormous effort to identify specific DNA sequence changes predisposing people to psychiatric, neurodegenerative, malignant, metabolic, and autoimmune diseases, but with only moderate success. Our findings represent a new way to look for the molecular cause of disease, and eventually may lead to improved diagnostics and treatment." Centre for Addiction and Mental Health |
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| Related Epigenetics Current Events and Epigenetics News Articles Evolutionarily preserved mechanism governs use of genes Researchers at Uppsala University have found that the protein coding parts of a gene are packed in special nucleosomes. The same type of packaging is found in the roundworm C elegans, which is a primeval relative of humans. Scientists Take Early Steps Toward Mapping Epigenetic Variability The study of eipigenetic variability in cells and tissues could someday help diagnose diseases more precisely and provide more targeted treatments for chronic ailments. Silenced genes as a warning sign of blood cancer In many types of cancer, parts of the genetic material of tumor cells are switched off by chemical labels called methyl groups. This kind of methyl labeling ranges among the epigenetic changes that do not change the sequence of DNA building blocks. Cancer's distinctive pattern of gene expression could aid early screening and prevention Distinctive patterns of genes turned off - or left on - in healthy versus cancerous cells could enable early screening for many common cancers and maybe help avoid them, Medical College of Georgia scientists say. New Piece Found in the Puzzle of Epigenetics A team of scientists led by Professor Dirk Eick of Helmholtz Zentrum München has identified the enzyme TFIIH kinase as an important factor in the epigenetic regulation of the cell nucleus enzyme RNA polymerase II. 100 reasons to change the way we think about genetics For years, genes have been considered the one and only way biological traits could be passed down through generations of organisms. New Method Developed by UC San Diego Bioengineers Gives Regenerative Medicine a Boost Bioengineers at UC San Diego have developed a breakthrough method for sequencing-based methylation profiling, which could help fuel personalized regenerative medicine and even lead to more efficient and cost-effective methods for studying certain diseases. New nucleotide could revolutionize epigenetics Anyone who studied a little genetics in high school has heard of adenine, thymine, guanine and cytosine -- the A,T,G and C that make up the DNA code. The new 'epigenetics:' Poor nutrition in the womb causes permanent genetic changes in the offspring The new science of epigenetics explains how genes can be modified by the environment, and a prime result of epigenetic inquiry has just been published online in The FASEB Journal: You are what your mother did not eat during pregnancy. Einstein scientists propose new theory of autism Scientists at Albert Einstein College of Medicine of Yeshiva University have proposed a sweeping new theory of autism that suggests that the brains of people with autism are structurally normal but dysregulated, meaning symptoms of the disorder might be reversible. More Epigenetics Current Events and Epigenetics News Articles |
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