XML Feed for RxPG News   Add RxPG News Headlines to My Yahoo!   Javascript Syndication for RxPG News

Research Health World General
 
  Home
 
 Latest Research
 Cancer
 Psychiatry
 Genetics
  X Chromosome
  Genetic Disorders
  Cloning
 Surgery
 Aging
 Ophthalmology
 Gynaecology
 Neurosciences
 Pharmacology
 Cardiology
 Obstetrics
 Infectious Diseases
 Respiratory Medicine
 Pathology
 Endocrinology
 Immunology
 Nephrology
 Gastroenterology
 Biotechnology
 Radiology
 Dermatology
 Microbiology
 Haematology
 Dental
 ENT
 Environment
 Embryology
 Orthopedics
 Metabolism
 Anaethesia
 Paediatrics
 Public Health
 Urology
 Musculoskeletal
 Clinical Trials
 Physiology
 Biochemistry
 Cytology
 Traumatology
 Rheumatology
 
 Medical News
 Health
 Opinion
 Healthcare
 Professionals
 Launch
 Awards & Prizes
 
 Careers
 Medical
 Nursing
 Dental
 
 Special Topics
 Euthanasia
 Ethics
 Evolution
 Odd Medical News
 Feature
 
 World News
 Tsunami
 Epidemics
 Climate
 Business
Search

Last Updated: Aug 19th, 2006 - 22:18:38

Genetics Channel
subscribe to Genetics newsletter

Latest Research : Genetics

   DISCUSS   |   EMAIL   |   PRINT
Genetic Gender Gap in Disease Risk, Drug Response
Jul 10, 2006, 06:29, Reviewed by: Dr. Anita Dhanrajani

"This is crucial, because once we understand the gender gap in these disease mechanisms, we can create new strategies for designing and testing new sex-specific drugs."

 
UCLA researchers report that thousands of genes behave differently in the same organs of males and females � something never detected to this degree. Published in the August issue of Genome Research, the study sheds light on why the same disease often strikes males and females differently, and why the genders may respond differently to the same drug.

"We previously had no good understanding of why the sexes vary in their relationship to different diseases," explained Xia Yang, Ph.D., first author and postdoctoral fellow in cardiology at the David Geffen School of Medicine at UCLA. "Our study discovered a genetic disparity that may explain why males and females diverge in terms of disease risk, rate and severity."

"This research holds important implications for understanding disorders such as diabetes, heart disease and obesity, and identifies targets for the development of gender-specific therapies," said Jake Lusis, Ph.D., co-investigator and UCLA professor of human genetics.

The UCLA team examined brain, liver, fat and muscle tissue from mice with the goal of finding genetic clues related to mental illnesses, diabetes, obesity and atherosclerosis. Humans and mice share 99 percent of their genes.

The scientists focused on gene expression -- the process by which a gene's DNA sequence is converted into cellular proteins. With the help of Rosetta Informatics, the team scrutinized more than 23,000 genes to measure their expression level in male and female tissue.

What they found surprised them. While each gene functioned the same in both sexes, the scientists found a direct correlation between gender and the amount of gene expressed.

"We saw striking and measurable differences in more than half of the genes' expression patterns between males and females," said Dr. Thomas Drake, co-investigator and UCLA professor of pathology. "We didn't expect that. No one has previously demonstrated this genetic gender gap at such high levels."

UCLA is the first to uncover a gender difference in gene expression in fat and muscle tissue. Earlier studies have identified roughly 1,000 sex-biased genes in the liver, and other research has found a combined total of 60 gender-influenced genes in the brain � about one-tenth of what the UCLA team discovered in these organs.

Even in the same organ, the researchers identified scores of genes that varied in expression levels between the sexes. Gender consistently influenced the expression levels of thousands of genes in the liver, fat and muscle tissue. This effect was slightly more limited in the brain, where hundreds, not thousands, of genes showed different expression patterns.

"Males and females share the same genetic code, but our findings imply that gender regulates how quickly the body can convert DNA to proteins," said Yang. "This suggests that gender influences how disease develops."

The gender differences in gene expression also varied by tissue. Affected genes were typically those most involved in the organ's function, suggesting that gender influences important genes with specialized roles, not the rank-and-file.

In the liver, for example, the expression of genes involved in drug metabolism differed by sex. The findings imply that male and female livers function the same, but work at different rates.

"Our findings in the liver may explain why men and women respond differently to the same drug," noted Lusis. "Studies show that aspirin is more effective at preventing heart attack in men than women. One gender may metabolize the drug faster, leaving too little of the medication in the system to produce an effect."

"At the genetic level, the only difference between the genders is the sex chromosomes," said Drake. "Out of the more than 30,000 genes that make up the human genome, the X and Y chromosomes account for less than 2 percent of the body's genes. But when we looked at the gene expression in these four tissues, more than half of the genes differed significantly between the sexes. The differences were not related to reproductive systems � they were visible across the board and related to primary functions of a wide variety of organs."

The UCLA findings support the importance of gender-specific clinical trials. Most medication dosages for women have been based on clinical trials primarily conducted on men.

"This research represents a significant step forward in deepening our understanding of gender-based differences in medicine," said Dr. Janet Pregler, director of the Iris Cantor-UCLA Women's Health Center. The center's executive advisory board, a group of businesswomen interested in advancing women's health, helped fund the study.

"Many of the genes we identified relate to processes that influence common diseases," said Yang. "This is crucial, because once we understand the gender gap in these disease mechanisms, we can create new strategies for designing and testing new sex-specific drugs."
 

- August issue of Genome Research
 

www.ucla.edu

 
Subscribe to Genetics Newsletter
E-mail Address:

 

The National Heart, Lung and Blood Institute; the National Institute of Diabetes and Digestive and Kidney Diseases; and the UCLA National Center for Excellence in Women's Health also supported the study. Coauthors included Susanna Wang, Leslie Ingram-Drake and Arthur Arnold, all from UCLA, and Eric Schadt of Rosetta Inpharmatics, a subsidiary of Merck and Co.

Related Genetics News

New research into csd genes could help designing strategies for breeding honey bees
Williams Syndrome, the brain and music
Genetic mutation identified as cause of cranio-lenticulo-sutural dysplasia
Chance Fluctuations in mRNA Output in Mammalian Cells
Transposon Silencing Keeps Jumping Genes in Their Place
GATA2 - predicting susceptibility to coronary artery disease
Exploring genetics of congenital malformations
Genome insertions and deletions (INDELs) provide expanded view of human genetic differences
BRIT1 gene identified as protector of DNA
FDA Approves Idursulfase As First Treatment for Hunter Syndrome


For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 

© Copyright 2004 onwards by RxPG Medical Solutions Private Limited
Contact Us