After decades of long research, scientists have designed a genetic test performed on blood taken from pregnant women that may one day help doctors diagnose Down's syndrome and other genetic disorders with less risk of miscarriage.

This non-invasive prenatal test for Down syndrome would replace amniocentesis, which uses amniotic fluid extracted from the uterus and can cause complications including infection and miscarriage, scientists from Stanford University and the Howard Hughes Medical Institute say

- A new study suggests that the AIDS virus has been around for 100 years.

Researchers published their findings in the journal Nature. They have found through genetic analysis that the virus likely originated in humans sometime between 1884 and 1924, with a more focused estimate at 1908

The discovery of a 50-year-old human tissue sample in an African university shows that HIV/AIDS pandemic in humans originated at least three decades earlier than previously thought.

Michael Worobey, an evolutionary biologist at the University of Arizona, Tucson, and lead author of the study suggests that AIDS may have been triggered by rapid urbanization in west-central Africa during the early 20th century and the virus most likely started circulating among humans in sub-Saharan Africa sometime between 1884 and 1924

Researchers have found a genetic link between obesity and colon cancer that may help pave the way for more effective screening tests for the disease. It may also lead to greater accuracy in predicting the people who are at the greatest risk of the disease, experts say.

People who inherit a variation of a gene called ADIPOQ, which results in the formation of a fat hormone called adiponectin, are 30 percent less likely to develop colon cancer, say researchers from University of Alabama Comprehensive Cancer Center

One of the pending bills waiting for California Gov. Arnold Schwarzenegger's signature is a proposal to expand the coverage of medical policies to include maternity service, tests for the HPV virus, which could cause cervical cancer, treatment for mental health and substance abuse problems.

But with the wider medical coverage for 18 million California residents, premiums would go up by $383 million annually, equivalent to 0.5 percent of the $74 billion that employers and individuals pay, according to data from the University of California's Health Benefits Review Program