Two middle-age women, Sue and Sheila,  are born as identical twins, but one of them is aging faster by 10 years. Two identical twin brothers are so alike their hair went grey at the same time, but one of them cannot tolerate pain as much as the other. And there is a six-year old girl who was diagnosed with leukemia but her sister is completely healthy.
Identical twins are monozygotic – they come from the same single egg that split early in development, and therefore share the same exact DNA, so we expect them to look alike, have the …read more

HA! Don’t laugh, but this study found genetic evidence that our neighbors across the pond have a unique sense of humor, and apparently it’s the negative kind.
A survey of 4,000 twins suggested that British humor, those that are filled with sarcasm and self-deprecation, is linked to genes in British men and women, but not shared by Americans!
The “positive” kind of humor, like telling jokes and looking on the bright side, is shared by both sides of the Atlantic. But the negative kind, like biting sarcasm and teasing, are genetically linked only in Britain.
The researchers admit that developing a taste for …read more

Has your mom ever told you not to watch TV too closely? Have you been told as a child that reading too much (or cross-stitching too much) will hurt your eyes? That’s not too far out an idea, at all.
Myopia or nearsightedness is a condition where one has trouble seeing objects that are farther away. Symptoms, usually developing in early childhood and teen years include squinting when trying to concentrate on an object far away, or holding an object very close to the face (to read, or to see it clearer). The person may want to sit very near the …read more

It doesn’t come as a surprise that childhood abuse has long term effects that show itself way into adulthood. Adults with a history of childhood abuse are known to have higher risks of psychological problems and difficulty responding to stress. But a recent study found that abuse in early childhood can permanently change how certain genes in the brain work, so much, that the risk of suicide is increased.
A Canadian study led by Michael Meaney examined the gene for glucocorticoid receptor – which controls a brain’s response to stress – in 12 suicide victims with a history of abuse, …read more

A new theory has emerged about the genetic basis of mental disorders, and it has to do with our parental genes fighting for dominance.
The theory outlines that genes from the father’s sperm are in an evolutionary tug-of-war with genes from the mother’s egg. Whichever becomes dominant tips brain development that direction. An excerpt from the NY Times –
A strong bias toward the father pushes a developing brain along the autistic spectrum, toward a fascination with objects, patterns, mechanical systems, at the expense of social development. A bias toward the mother moves the growing brain along what the …read more

An interesting article on the suicidal brain came out of Biological Psychiatry this week – A gene for neurotransmitter reception is shut down in the suicidal brain.
Scientists found chemical changes relating to regulation of cell development were happening in the brains of people with major depressive disorder who committed suicide. The gene controlling neurotransmitter reception plays a role in regulating behavior. It’s very interesting. Without proper regulation of behavior, then I assume the behavior would be erratic and contribute to suicidal tendencies.
This is another example of epigenetics at work. Without even changing the DNA structure, environment can cause …read more

Researchers have found marked genetic differences between brains of men who committed suicide and the brains of men who did not. Of those individuals studied, all had been victims of child abuse.
Even though the genetic sequence was the same in the suicide and non-suicide brains, researchers at the McGill University, Montreal, Quebec, led by Moshe Szyfa, discovered that epigenetic markings were different. That is, the researchers noted a chemical coating on genes that was influenced by environmental factors. In this unique study, the DNA of male suicide victims from Quebec was analysed. The 13 people who committed suicide all had been …read more