Entries in genetic mutation (3)


PTSD, Depression Passed Through Generations, Study Finds

Jupiterimages/Thinkstock(LOS ANGELES) -- Researchers at UCLA have identified mutations within three genes, which according to them may make some people more likely to develop symptoms of post-traumatic stress disorder (PTSD) and depression.

The researchers analyzed 200 adults from 12 multigenerational families who were exposed to the 1988 earthquake in Spitak, Armenia, most of whom saw dead bodies lying in the streets and people who were severely injured.

The participants underwent psychological screening and a genetic test 14 years after experiencing the earthquake.  The researchers found that people with mutations in any of three genes responsible for secreting the happiness hormone serotonin had PTSD and depression symptoms.

Previous studies have suggested that PTSD is heritable among siblings who experience traumatic situations such as war.  But this study suggests that the disorder is also heritable through multiple generations, according to Julia Bailey, assistant professor in the department of epidemiology at UCLA, and co-author of the study.

“We found that both PTSD and depression are heritable and that they share genes,” said Bailey, who added that the findings are consistent with previous research suggesting a genetic connection between PTSD and depression.

Unlike previous studies, the participants in this study were not previously diagnosed with PTSD or depression, nor were they seeking any sort of treatment for their symptoms.

However, all of the participants were of the same ethnic background, so the findings may not apply to all people, the researchers wrote in their study published Tuesday in the Journal of Affective Disorders.

Copyright 2012 ABC News Radio


Study Finds DNA Mutation Rate Varies for Individuals

Comstock/Thinkstock(CAMBRIDGE, England) -- In the popular comic book and movie series X-Men, the characters are known to have superpowers through mutations in their DNA. In actuality, humans are born with genetic mutations and a study conducted by the Wellcome Trust Sanger Institute of Cambridge, United Kingdom took a closer look at such mutations and how these mutations were passed on from parents to children.

In the study, researchers screened the entire genetic sequence of 6 individuals, two sets of parents with one child. The findings of the study, which were published in Nature Genetics, revealed that the children received about 60 DNA mutations from their parents, but that the large majority of new mutations arose spontaneously in the children. 

An interesting observation, however, came from analyzing the mutations that came from the parents.  Since the mid-1900s, it’s been thought that more mutations arise in sperm than in eggs because the speed at which sperm are created makes them more vulnerable to genetic mutations. This hypothesis was a little shaken by the finding that in one of the families, the father's DNA contributed 92 percent while in the other only for 36 percent of the mutations the child inherited from the parents. 

The study has found that the mutation rate varies from individual to individual, or that some people have mechanisms that reduce the likelihood of mutations.

Copyright 2011 ABC News Radio


Genetic Mutation May Lead to Violent and Reckless Behavior

Photo Courtesy - Getty Images(NEW YORK) -- In a discovery that could help scientists further understand impulsivity in humans, researchers have announced they found a genetic variant that may contribute to spontaneous violent behavior.

In a new study released in the journal Nature, a multinational research team examined the genes of 96 violent criminal offenders in Finland with behavioral disorders and compared it with DNA from a control group of 96 people in the country who had no such psychiatric diagnoses.

Scientists found that the criminal offenders were three times more likely to have a genetic mutation, known as the HTR2B Q20* mutation, than the control group.

The offenders had been diagnosed with antisocial personality disorder, borderline personality disorder or intermittent explosive disorder -- all conditions with symptoms of impulsive aggression.

The mutation was found to affect the brain's levels of serotonin, a neurotransmitter that affects mood, appetite, sleep and impulsive behavior.

"Impulsivity is a normal dimension of behavior, but it also plays a role in many psychiatric disorders, including alcoholism and suicidalism," said Dr. David Goldman, chief of the Laboratory of Neurogenetics at the National Institute on Alcohol Abuse and Alcoholism, in Bethesda, Md., and senior author of the study. "These disorders are often difficult to disentangle at the causal level, but by studying traits, we can find genes that contribute to important aspects of them."

Researchers specifically conducted the study in Finland because of its unique population and medical genetics. Goldman said modern Finns descend from a relatively small number of original settlers, which increased the chance of finding specific genes that influence impulsive behavior.

"Finns have the same degree of genetic diversity as people from other cultures, but their genetic disease diversity is reduced," said Goldman. "Genetic heterogeneity tends to be reduced in Finland because of its unique population, which was founded by two major waves of migration." 

Copyright 2010 ABC News Radio

ABC News Radio