Gene therapy can occur inside the body, but it can also be completed outside the body—with scientists treating cells in the lab, and then those corrected cells are transplanted back into the body.

Gene therapy, a hope of the Human Genome Project, has successfully treated a baby born with a rare urea cycle disorder that causes toxic ammonia level buildup.

A single-gene mutation in the FOXC2 gene gave actress Elizabeth Taylor two rows of eyelashes.

See this list of FDA-approved gene therapies, including offerings for inherited conditions as well as some forms of cancer.

How personalized gene-editing saved a baby's life

KJ Muldoon had a 50% chance of surviving a genetic mutation until doctors developed a one-of-a-kind gene-editing therapy. In an interview with one of the researchers behind the treatment, learn what it will take to make personalized genetic medicine possible for everyone.

Epigenetic editing—altering gene expression by removing or adding chemical groups on DNA—is making significant strides in the lab, even lowering cholesterol in monkey experiments by about 70%. (Free w/email.)

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Changing a single letter in DNA can permanently alter an organism

Genetic mutations occur when cells replicate, which requires a copy of DNA to be created, and involve substituting, deleting, or inserting letters in a cell's genetic code. Mutations can be caused by normal cellular processes, chemical exposure (e.g., carcinogens), or radiation and may result in genetic disorders or genetic variations that drive evolution.

Gene therapy is restoring hearing among kids with genetic deafness

Gene therapy for profound genetic deafness has been advancing in recent years, with multiple clinical trials enabling hearing at normal levels for the first time without hearing aids or cochlear implants. The therapies target hearing loss caused by mutations in the OTOF gene that codes for a protein called otoferlin. That protein normally plays a key role in relaying sound signals in synaptic transmission between the ear's inner hair cells and the auditory nerve.

In 2026, the FDA proposed a novel approach to expedite reviews of gene therapies for patients with rare genetic disorders such as cystic fibrosis, potentially bypassing the need for years-long clinical trials if approved.

See how a novel gene editing technique called base editing can create changes in a single DNA base, using a more precise targeting approach than CRISPR-Cas9.

CRISPR is a gene-editing tool that lets scientists cut out and replace damaged DNA

Originally a bacterial defense system against viruses, CRISPR uses guide RNA and a protein called Cas9 to identify and cut specific DNA sequences. Scientists can repurpose this system to switch off faulty genes, insert new ones to treat genetic diseases, or modify organs grown in other animals so that they appear less foreign to a human immune system.

CRISPR allows scientists to cut out and replace faulty or unwanted DNA, which can help treat genetic disorders, such as sickle cell disease, and create genetically modified organisms, such as allergen-free foods.

Synthetic biology can prevent extinction by creating create disease-resilient plants and animals

Through gene editing and the deployment of artificial cells, scientists can leverage learnings from the genetic sequencing of animals with known resistances to protect endangered species. Gene editing of certain species, such as mosquitoes, can also reduce their ability to spread diseases like malaria between humans.

Genetic engineering will change everything forever

Designer babies, the end of diseases, genetically modified humans that never age. Outrageous things that used to be science fiction are suddenly becoming reality. As scientists increasingly understand how specific genes cause disease, the possibility of engineering our genes to not only "fix" problems but enhance our natural ability grows.

The 'Armamentarium' is a set of new gene therapy tools—including viruses that could shuttle therapies into the body—designed to fight brain diseases.

Genetic engineering has accelerated millennia of altering various crops' genes

Although farmers have long cross-bred crops to obtain plants with specific colors, sizes, and other characteristics, these processes took significant time. Today, genetic modification in agriculture involves scientists altering an organism's DNA for various purposes, including enhancing pathogen resistance, removing allergens, and delaying spoilage.

In 2023, the FDA approved gene therapy for sickle cell disease, enabling one-time infusion bespoke treatments that use a patient's own stem cells to effectively cure a painful condition that disproportionately affects people of African American descent.

Scientists using gene therapy recently managed to regenerate retinal cells in the lab—a breakthrough for mammals that could potentially lead to future treatments for human retinal diseases.

Tumor genetic profiling can lead to targeted treatments

Genetic profiling of tumors—based on a sample from the tumor, a patient's blood, or both—can help clinicians determine if targeted therapies known to block the growth of certain types of tumors would be appropriate for specific patients.

See how CAR-T cell therapy works to help fight cancer

Short for chimeric antigen receptor T-cell therapy, CAR-T Cell Therapy helps augment the body's own ability to attack cancer cells. It's a cell-based gene therapy that alters the genes in a person's T cells—which are a type of immune cell—to help them beat back cancerous growths.

Gene therapy for a rare type of deafness is allowing deaf children and adults to hear for the first time, according to research results reported in April 2026.

Around 5 million of our 3 billion DNA letters differ between individuals

Genetic testing examines gene variants to help explain disease symptoms. It explores how genetic differences between individuals can be used to understand risks of developing diseases like Huntington's Disease or passing variants linked to disease onto offspring.

Recombinant DNA technology turns microorganisms into protein factories

Genes for molecules such as insulin can be inserted into loops of bacterial DNA called plasmids and reinserted into bacteria. Once placed in fermentation tanks, these bacteria use the gene to produce these molecules, which are then harvested and purified for eventual use.

Synthetic biology transforms cells into custom DNA foundries

At companies like Ginkgo Bioworks, researchers are reprogramming cells to act as workshops that can create custom molecules, such as medicines and fertilizers, by stitching together DNA sequences—often in novel combinations—before inserting them into an organism's genome.

A planned clinical trial to treat a rare lysosomal storage disorder in utero has buoyed hopes of providing prenatal gene therapies, but it was still awaiting FDA approval to begin enrolling patients as of May 2026.

Move over gene editing, scientists can edit your epigenome

Instead of deleting genes, epigenetic editing modulates their activity. A new paper tests if it’s able to undo a genetic effect of early alcohol exposure.

Genetic drug matching, called pharmacogenomics, can help avoid dangerous drug reactions

Certain gene variants can affect how quickly or slowly medications are broken down in the body, affecting drug effectiveness and the risk of drugs failing. Such testing is often not covered by insurance companies though research indicates if these tests were performed for more than six drugs across the US population, avoided ailments would likely climb into the hundreds of thousands. (Some users may encounter a paywall.)

CRISPR-Cas9 enables precise genome editing using a simple RNA-guided system

Jennifer Doudna's research uncovered how bacteria use the tool as an immune defense by cutting viral DNA. She and Emmanuelle Charpentier received the 2020 Nobel Prize in chemistry for showing how this mechanism could be engineered to target and edit genes in living cells.

CRISPR can't fix faulty mitochondria

Gene editing via CRISPR could theoretically fix many issues in biology, but editing the mitochondrial genome has remained challenging. In recent years, there has been some progress reaching these cellular powerhouses. (Some users may experience a paywall.)

A first-of-its-kind clinical trial taps livers from gene-edited pigs to clean blood

The experimental dialysis-like treatment from United Therapeutics, eGenesis, and OrganOx, is designed to help people with liver failure. The therapy, which involves attaching the modified pig liver externally, filters a patient’s blood so their own livers can temporarily rest and perhaps heal.

mRNA vaccines alter immune response, not DNA, to combat diseases like cancer.

While humans have been genetically modifying plants for millennia by selectively breeding organisms with certain traits, gene-editing tools like CRISPR have further enhanced plants, conferring resistance to drought, pests, and diseases.

Somatic expansion, the lifelong growth of specific repeating DNA sequences, is being studied as a potential treatment target for Huntington's disease and other disorders.

Cells translate genetic information into proteins using RNA messengers

Genes are segments of DNA, each composed of a sequence of nitrogenous bases. Within the nucleus, these sequences are copied into a single strand of ribonucleic acid during transcription. This strand leaves the nucleus and is translated by ribosomes into a chain of amino acids that folds into a functional protein.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

A scientist successfully treated her own breast cancer by injecting the tumor with lab-grown viruses.

TIGR may supplement CRISPR by providing more refined DNA targeting

The tandem interspaced guide RNA is primarily found in viruses—unlike CRISPR, which is bacterial in origin—and is smaller than CRISPR, making it easier to deliver into cells. The TIGR-Tas system appears to read both sides of the DNA double helix and opens a smaller segment of DNA for repairs, improving the precision of single letter modification.