October 9, 2013 |
Scientists have discovered two gene mutations that they believe are associated with an increased risk of eating disorders. Anorexia nervosa and bulimia often run in families, but these eating disorders are complex, and it has proved difficult to identify the paths. But, using two families with very high incidences of eating disorders, scientists say they found rare mutations, one in each family, that were associated with the people who had the disorders. The study suggests that mutations that decrease the activity of a protein that turns on the expression of other genes - called a transcription factor - increase the risk.
March 3, 2011 |
Two studies released Wednesday by the journal Nature show that work remains before so-called induced pluripotent stem (iPS) cells are ready for use in laboratory studies or clinical therapies. iPS cells are body cells that are programmed to unwind back into an embryonic state. Like embryonic stem cells, they have potential to develop into any other type of cell in the body. But they don't reprogram perfectly, researchers are showing. About a month ago, a team at the Salk Institute showed that iPS cells hold on to "memory" of their past identity.
August 22, 2012 |
Men who become fathers later in life pass on more brand-new genetic mutations to their offspring, a study has found - probably contributing to disorders such as autism and schizophrenia in the next generation. The finding, published online Wednesday in the journal Nature , buttresses earlier observations that rates of autism and some other disorders are more prevalent in children born of older fathers, sometimes by a factor of two or more, experts said. Though this has been observed for years from population studies, scientists had not known what lay behind it. The new research, made possible by recent advances in DNA-sequencing technology, also should help correct an overemphasis on the riskiness of women giving birth at older ages, some researchers said.
December 10, 2012 |
Human DNA contains myriad individual differences that influence a host of traits, be they eye color or the ability to digest milk. Now a study shows that most of those tiny genetic variations are rare - and they arose in the very recent history of our species. Joshua Akey, a geneticist at the University of Washington in Seattle, led a consortium of scientists who examined the DNA of 4,298 European Americans and 2,217 African Americans. Limiting their analysis to the parts of the genome that contain instructions for making proteins, the study authors found more than 1 million sites where the building blocks of DNA - the nucleotides known by the letters A, C, G and T - varied in at least one of the subjects.
June 8, 2011 |
Autism spectrum disorders can be caused by as many as 300 or so rare genetic mutations, scientists reported Wednesday. The research strongly implicates genetics, including spontaneous gene mutations, in the development of the disorder. But why do four times as many males as females develop autism spectrum disorder? In one of the three papers published in the journal Neuron , researchers suggest that girls are more resistant to gene mutations than boys. Girls seem to require a higher number of gene mutations to become afflicted with autism spectrum disorder.
June 9, 2011 |
Autism is not caused by one or two gene defects but probably by hundreds of different mutations, many of which arise spontaneously, according to research that examined the genetic underpinnings of the disorder in more than 1,000 families. The findings, reported in three studies published Wednesday in the journal Neuron, cast autism disorders as genetically very complex, involving many potential changes in DNA that may produce, essentially, different forms of autism. The affected genes, however, appear to be part of a large network involved in controlling the development of synapses, the critical junctions between nerve cells that allow them to communicate, according to one of the three studies.