Rob Stein

For the first time, scientists have used the gene-editing technique CRISPR to try to edit a gene while the DNA is still inside a person's body.

The groundbreaking procedure involved injecting the microscopic gene-editing tool into the eye of a patient blinded by a rare genetic disorder, in hopes of enabling the volunteer to see. They hope to know within weeks whether the approach is working and, if so, to know within two or three months how much vision will be restored.

Updated at 11:50 a.m. ET

Federal health officials say they have resolved a problem that has hindered wide testing for the new coronavirus in the United States, a crucial practice for fighting the spread of the dangerous new infection.

A problem with one ingredient in test kits that the federal Centers for Disease Control and Prevention distributed to labs around the country had created a frustrating bottleneck in testing, requiring most testing to occur at the CDC in Atlanta.

Updated at 8:25 p.m. ET

Federal health officials issued a blunt message Tuesday: Americans need to start preparing now for the possibility that more aggressive, disruptive measures might be needed to stop the spread of the new coronavirus in the U.S.

The strongly worded warning came in response to outbreaks of the virus outside China, including in Iran, Japan, South Korea and Italy, which officials say have raised the likelihood of outbreaks occurring stateside.

Chunlin Leonhard spends most of her time alone in her room at a hotel at the Travis Air Force Base in California, anxiously reading the latest news about the coronavirus outbreak in China.

"I'm doing about as well as can be hoped for under the circumstances," Leonhard, 55, a New Orleans law professor, says during an interview over Skype.

Updated at 6:34 p.m. ET

A second person in the United States has been infected with a dangerous new coronavirus that is spreading in China, U.S. health officials announced Friday.

A woman in her 60s got infected with the virus while traveling in the Wuhan, China, area in late December and became ill after returning home to Chicago Jan. 13, according to officials from the federal Centers for Disease Control and Prevention and the Illinois and Chicago health departments.

Researchers have conducted a controversial study that involved paying dozens of young women at a hospital near Puerto Vallarta, Mexico, to get artificially inseminated so their embryos could be flushed out of their bodies and analyzed for research purposes.

The study showed that embryos created that way appear to be as healthy genetically as embryos created through standard in vitro fertilization. Physically, the embryos appear to, possibly, even be healthier, the study found.

When Victoria Gray was just 3 months old, her family discovered something was terribly wrong.

"My grandma was giving me a bath, and I was crying. So they took me to the emergency room to get me checked out," Gray says. "That's when they found out that I was having my first crisis."

Doctors are reporting the first evidence that genetically edited cells could offer a safe way to treat sickle cell disease, a devastating, incurable disorder that afflicts millions of people around the world.

Billions of cells that were genetically modified with the powerful gene-editing technique called CRISPR have started working, as doctors had hoped, inside the body of the first sickle cell patient to receive the experimental treatment, according to highly anticipated data released Tuesday.

The powerful gene-editing technique known as CRISPR has raised a lot of hope in recent years for its potential to offer new ways to treat many diseases, including cancer. But until now, scientists have released very little information about results of tests in patients.

On Wednesday, researchers revealed data from the first study involving U.S. cancer patients who received cells genetically modified with CRISPR.

Scientists have created a new way to edit DNA that appears to make it even easier to precisely and safely re-write genes.

The new technique, called prime editing, is designed to overcome some of the limitations of CRISPR. That technique, often described as a kind of molecular scissors for genes, has been revolutionizing scientific research by letting scientists alter DNA.

Victoria Gray slides open a closet door, pulls out a suitcase and starts packing piles of clothes.

"My goodness," says Gray. "Did I really bring all this?"

Gray, who has sickle cell disease, is the first patient with a genetic disorder whom doctors in the United States have tried to treat using the powerful gene-editing technique CRISPR.

There's been a lot of excitement lately that the powerful gene-editing technique CRISPR could offer a new way to treat health problems ranging from cancer to blindness.

But there hasn't been much direct scientific evidence in actual patients about whether it might work or would be safe — until now.

Chinese scientists have published the first report in a scientific journal of an attempt to use CRISPR-edited cells in a patient--a 27-year-old man who is HIV-positive.

Scientists have invented a device that can quickly produce large numbers of living entities that resemble very primitive human embryos.

Researchers welcomed the development, described Wednesday in the journal Nature, as an important advance for studying the earliest days of human embryonic development. But it also raises questions about where to draw the line in manufacturing "synthetic" human life.

First it was human embryos. Now scientists are trying to develop another way to modify human DNA that can be passed on to future generations, NPR has learned.

Reproductive biologists at Weill Cornell Medicine in New York City are attempting to use the powerful gene-editing technique called CRISPR to alter genes in human sperm. NPR got exclusive access to watch the controversial experiments underway.

Updated at 4:05 p.m. ET

For the first time, doctors in the U.S. have used the powerful gene-editing technique CRISPR to try to treat a patient with a genetic disorder.

Scientists have created living entities that resemble very primitive human embryos, the most advanced example of these structures yet created in a lab.

The researchers hope these creations, made from human embryonic stem cells, will provide crucial new insights into human development and lead to new ways to treat infertility and prevent miscarriages, birth defects and many diseases. The researchers say this is the first time scientists have created living models of human embryos with three-dimensional structures.

A Russian scientist says he wants to create more genetically modified babies, flouting international objections that such a step would be premature, unethical and irresponsible.

Denis Rebrikov, a molecular biologist who heads a gene-editing lab at the Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology in Moscow, claims he has developed a safe — and therefore acceptable — way to create gene-edited babies.

There are new concerns about the world's first genetically modified babies.

It appears that the genetic variation a Chinese scientist was trying to re-create when he edited twin girls' DNA may be more harmful than helpful to health overall, according to a study published Monday. The study, in Nature Medicine, involves the DNA of more than 400,000 people.

In the hope of finding a new way to fight malaria, scientists have used a spider gene to genetically engineer a fungus to produce a venom that can quickly kill mosquitoes.

The modified fungus was a highly effective mosquito killer in the first tests mimicking conditions in sub-Saharan Africa, where malaria remains a major public health problem, researchers reported Thursday in the journal Science.

The federal Food and Drug Administration has approved a gene therapy for a rare childhood disorder that is now the most expensive drug on the market. It costs $2.125 million per patient.

But for those patients lucky enough to get it, it appears it can save their lives with a one-time treatment.

Three-year-old Donovan Weisgarber is one of those patients. When he was born he seemed perfectly healthy. But within weeks, it became clear something was terribly wrong.

Alphonso Evans rolls his wheelchair into a weight machine in the gym at the Charlie Norwood VA Medical Center in Augusta, Ga.

"I'm not so much worried about dying from a heart attack or diabetes, because I'm active. I know what to do to work against it: watch what I eat, exercise," Evans says. "But what do I do about an infection? Or fighting off a bacteria — something inside me that I don't see until it's too late?"