Rob Stein

We all know that nobody's perfect. But now scientists have documented that fact on a genetic level.

Researchers discovered that normal, healthy people are walking around with a surprisingly large number of mutations in their genes.

It's been well known that everyone has flaws in their DNA, though, for the most part, the defects are harmless. It's been less clear, however, just how many mistakes are lurking in someone's genes.

When Christine Rowan gave birth prematurely in August, her new baby was having problems breathing. So Rowan brought her daughter, Zoe, to the Children's National Medical Center in Washington, D.C., for genetic testing.

"It's funny because when we first had the testing done, we didn't even really think about the fact the testing was going to lay out all of her DNA," says Rowan, 32, who lives in Northern Virginia.

But while Rowan and her husband were waiting for the results, questions started popping into their heads.

Members of a House subcommittee clashed repeatedly Wednesday with U.S. Food and Drug Commissioner Margaret Hamburg over the outbreak of meningitis caused by contaminated steroid injections.

Public health officials are warning that people in areas devastated by Superstorm Sandy face many risks in the aftermath and are urging people to protect themselves from health threats in the water, air and even their refrigerators.

As millions of people try to put their lives back together, the most obvious threat is the floodwaters themselves. In many places, the water could be a toxic stew.

Geneticist reported Wednesday that they had crossed a threshold long considered off-limits: They have made changes in human DNA that can be passed down from one generation to the next.

The researchers at Oregon Health & Science University in Portland say they took the step to try to prevent women from giving birth to babies with genetic diseases. But the research is raising a host of ethical, social and moral questions.

Doctors who specialize in treating infertility are making a big change in their position on a controversial practice. The American Society for Reproductive Medicine (ASRM) has concluded that freezing women's eggs to treat infertility should no longer be considered "experimental."

The group plans to officially announce the change on Monday.

Scientists in Japan report they have created eggs from stem cells in a mammal for the first time. And the researchers went on to breed healthy offspring from the eggs they created.

While the experiments involved mice, the work is being met with excitement — and questions — about doing the same thing for humans someday.