(Press-News.org) Researchers from the University of Helsinki analyzed thoroughly the commonly occurring genetic variation in chromosome X, one of the two sex-determining chromosomes, in almost 25,000 Northern European individuals with diverse health-related information available. The aim of the study was to find genetic factors that could explain individual differences in several traits, including BMI, height, blood pressure and lipid levels. In addition, the researchers also investigated whether the X chromosome would contribute to some of the well-known differences between men and women in certain traits, such as height. Hundreds of genetic variants having an effect on these traits have already been identified, but, given its unique nature, the X chromosome has been neglected in most of these previous studies.
The results were published in PLOS Genetics journal today, February 6th.
"Studying the X chromosome has some particular challenges. The fact that women have two copies of this chromosome and men only one has to be taken into account in the analysis. We nevertheless wanted to take up the challenge since we had a strong belief that opening 'the X files' for research would reveal new, interesting biological insights", says Dr. Taru Tukiainen who is currently working at the Massachusetts General Hospital in Boston.
The study showed that a genetic variant close to ITM2A, a gene that has a role in cartilage development, is frequent among the people being shorter than average. The identified variant, which is present in more than a third of Europeans, was also shown to increase the expression of ITM2A, suggesting that the more the gene is expressed the shorter the person will be. Interestingly, the effect of this variant on height was shown to be much stronger in women.
"The double dose of X-chromosomal genes in women could cause problems during the development. To prevent this, there is a process by which one of the two copies of the X chromosome present in the cell is silenced. When we realized that the height associated variant we identified was nearby a gene that is able to escape the silencing we were particularly excited", explains Professor Samuli Ripatti, the principal investigator behind the study.
"Because both copies of ITM2A remain active, the gene is expressed in higher levels in women. Identifying associations in regions like this where X-chromosomal gene doses are not balanced between men and women can be particularly valuable in helping us to understand why some characteristics differ between sexes", he continues.
"Based on our calculations, this variant accounts for a significant, though small proportion, 1-2% of the current difference in mean height between men and women in the Finnish population.
Also two other new X-chromosomal regions, one associating with fasting insulin levels and the other with height, were identified in this study. Neither of these showed any evidence of sex difference in the strength of the genetic effect.
INFORMATION: END
Opening 'the X-files' helped researchers to understand why women and men differ in height
2014-02-06
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Theorists predict new forms of exotic insulating materials
2014-02-06
CAMBRIDGE, Mass-- Topological insulators — materials whose surfaces can freely conduct electrons even though their interiors are electrical insulators — have been of great interest to physicists in recent years because of unusual properties that may provide insights into quantum physics. But most analysis of such materials has had to rely on highly simplified models.
Now, a team of researchers at MIT has performed a more detailed analysis that hints at the existence of six new kinds of topological insulators. The work also predicts the materials' physical properties in ...
Researchers pinpoint protein associated with canine hereditary ataxia
2014-02-06
Researchers from North Carolina State University have found a link between a mutation in a gene called RAB 24 and an inherited neurodegenerative disease in Old English sheepdogs and Gordon setters. The findings may help further understanding of neurodegenerative diseases and identify new treatments for both canine and human sufferers.
Hereditary ataxias are an important group of inherited neurodegenerative diseases in people. This group of diseases is the third most common neurodegenerative movement disorder after Parkinson's and Huntington's diseases.
In people with ...
Nutritional supplement improves cognitive performance in older adults, study finds
2014-02-06
Tampa, FL (Feb. 6, 2014) – Declines in the underlying brain skills needed to think, remember and learn are normal in aging. In fact, this cognitive decline is a fact of life for most older Americans.
Therapies to improve the cognitive health of older adults are critically important for lessening declines in mental performance as people age. While physical activity and cognitive training are among the efforts aimed at preventing or delaying cognitive decline, dietary modifications and supplements have recently generated considerable interest.
Now a University of South ...
Immune system 'overdrive' in pregnant women puts male child at risk for brain disorders
2014-02-06
Johns Hopkins researchers report that fetal mice — especially males — show signs of brain damage that lasts into their adulthood when they are exposed in the womb to a maternal immune system kicked into high gear by a serious infection or other malady. The findings suggest that some neurologic diseases in humans could be similarly rooted in prenatal exposure to inflammatory immune responses.
In a report on the research published online last week in the journal Brain, Behavior and Immunity, the investigators say that the part of the brain responsible for memory and spatial ...
Source of chlamydia reinfections may be GI tract
2014-02-06
The current standard of care treatment for chlamydia sometimes fails to eradicate the disease, according to a review published ahead of print in Infection and Immunity, and the culprit may be in the gut.
Chlamydia trachomatis not only infects the reproductive tract, but abides persistently—though benignly—in the gastrointestinal tract. There it remains even after eradication from the genitals by the antibiotic, azithromycin, says first author Roger Rank, of the Arkansas Children's Research Institute, Little Rock. And that reservoir is likely a source of the all-too-common ...
Scientific review points to supplement users engaging in a pattern of healthy habits
2014-02-06
Washington, D.C., February 6, 2014—Dietary supplement users take these products as just one component of a larger effort to develop a healthier lifestyle, according to a newly published review in Nutrition Journal, a peer-reviewed scientific publication. The review, "Health Habits and Other Characteristics of Supplement Users" (Nutrition Journal.2014, 13:14), co-authored by Council for Responsible Nutrition (CRN) consultant Annette Dickinson, Ph.D., and CRN's senior vice president, scientific and regulatory affairs, Duffy MacKay, N.D., examined data from 20 peer-reviewed ...
Global regulator of mRNA editing found
2014-02-06
An international team of researchers, led by scientists from the University of California, San Diego School of Medicine and Indiana University, have identified a protein that broadly regulates how genetic information transcribed from DNA to messenger RNA (mRNA) is processed and ultimately translated into the myriad of proteins necessary for life.
The findings, published today in the journal Cell Reports, help explain how a relatively limited number of genes can provide versatile instructions for making thousands of different messenger RNAs and proteins used by cells in ...
Toxin from brain cells triggers neuron loss in human ALS model
2014-02-06
NEW YORK, NY (February 6, 2014) — In most cases of amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, a toxin released by cells that normally nurture neurons in the brain and spinal cord can trigger loss of the nerve cells affected in the disease, Columbia researchers reported today in the online edition of the journal Neuron.
The toxin is produced by star-shaped cells called astrocytes and kills nearby motor neurons. In ALS, the death of motor neurons causes a loss of control over muscles required for movement, breathing, and swallowing. Paralysis and death ...
New insight into an emerging genome-editing tool
2014-02-06
The potential is there for bacteria and other microbes to be genetically engineered to perform a cornucopia of valuable goods and services, from the production of safer, more effective medicines and clean, green, sustainable fuels, to the clean-up and restoration of our air, water and land. Cells from eukaryotic organisms can also be modified for research or to fight disease. To achieve these and other worthy goals, the ability to precisely edit the instructions contained within a target's genome is a must. A powerful new tool for genome editing and gene regulation has ...
Credit card-sized device could analyze biopsy, help diagnose pancreatic cancer in minutes
2014-02-06
Pancreatic cancer is a particularly devastating disease. At least 94 percent of patients will die within five years, and in 2013 it was ranked as one of the top 10 deadliest cancers.
Routine screenings for breast, colon and lung cancers have improved treatment and outcomes for patients with these diseases, largely because the cancer can be detected early. But because little is known about how pancreatic cancer behaves, patients often receive a diagnosis when it's already too late.
University of Washington scientists and engineers are developing a low-cost device that ...