Usher Syndrome, a rare genetic disorder, causes progressive hearing and vision loss

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.

Age-related hearing loss, known as presbycusis, is a top cause of hearing loss

This video walks through the biology of why presbycusis (prez-buh-kyoo-sis) occurs and its etiology. This type of hearing loss is gradual and typically starts with reductions in the ability to hear high-pitched sounds.

Carrier screening enables individuals without symptoms to see if they carry a gene for disease

Some conditions are autosomal recessive—meaning a person may carry a gene for that condition, but not have symptoms. Cystic fibrosis, sickle cell disease, and Tay-Sachs disease are examples of autosomal recessive diseases in which a person must inherit two copies of a nonfunctioning gene—one from each parent—to develop disease.

Age-related macular degeneration is the primary cause of blindness in older Americans

Around 20 million Americans suffer from macular degeneration, and it's the leading cause of blindness in older Americans. Risk factors for age-related macular degeneration include aging, genetics, smoking, hypertension, obesity, and diet.

Using brain implants to restore vision

Several companies are attempting to create brain-computer interfaces that skip over retinas and optic nerves to allow visual input to go straight to the brain, potentially restoring some sight to the blind. Clinical trial findings suggest restored sight is sparse and manifests differently than a sighted person might expect, appearing as specks of "light" clusters called phosphenes to help differentiate one's surroundings.

Proteins with limited light sensitivity prevent humans from seeing all types of light

Specialized photoreceptor cells in the retina called cones each possess photopigments that activate when exposed to three ranges of visible light. Other forms of electromagnetic radiation outside the activation range do not generate signals for processing in the brain, thereby limiting average human vision to approximately 10 million colors.

Alkaptonuria was the first identified genetic disorder

In 1902, a rare recessive mutation was determined to cause alkaptonuria—a disease that induces dark pigmentation of connective tissue. The responsible gene was not isolated until the 1990s.

One theory claims the retinae of SAD patients may fail to adjust to less light in winter

Most people’s eyes become more sensitive to light in the winter months, but some do not. This failure to adjust causes ripple effects on those individuals’ biological clocks. This Ted-ED video provides a clear, brief, narrative explanation of the condition in six minutes.

Here’s why genetically identical sisters can have different colored eyes

The sequence of DNA that we inherit from our parents encodes directions for making our cells and giving us specific traits. Identical twins have the same DNA sequence, so how can one twin end up with a genetic disorder while the other twin does not? Robin Ball explains how the secret lies in X chromosome inactivation.

Hereditary hyperosmia is the official term for being a super-smeller

Some sniffers with this rare trait may be more sensitive to pleasant smells, while others may be more attuned to unpleasant scents. Some research suggests that certain genetic mutations are associated with a heightened sense of smell.

Individuals with synesthesia experience involuntarily overlapping sensations

Tasting words or seeing colors in music results from the brain retaining extrasensory connections from infancy. While most lose these neural pathways during development, about 4% of people are synesthetes, maintaining them without realizing it's unusual.

The deadly genetic disease that steals shut-eye

Few are haunted by fatal familial insomnia. This neurodegenerative disease is typically carried through bloodlines via genetic mutation of the prion protein gene, forcing the body to create abnormal and pathological protein variations that can corrupt normal versions. This article follows a musician as they attempt to come to terms with the FFI plaguing their family (and, possibly, their future).

Some men may be at elevated risk of inheriting tinnitus

A 2017 Swedish Twin Registry study suggests that bilateral tinnitus—when tinnitus occurs in both ears instead of just one—appears to be heritable, at least in men.

Leprosy affects the skin, eyes, and upper respiratory tract

Untreated, the disease can lead to permanent nerve damage and the loss of sensation in arms, legs, and other extremities. The exact form of transmission remains unclear, but scientists suspect it is spread via respiratory droplets over a prolonged period. (Warning: Graphic content, including photos of deformities.)

There's no cure for Ménière's disease, only medications to reduce frequency of attacks

Ménière's disease is an inner ear problem that can cause vertigo and hearing loss. Most of the time, Ménière's disease affects only one ear.

How to repair a baby’s broken heart

A rare disorder that prevents some babies from getting enough oxygen to their organs can be repaired through a series of three intricate surgeries. This article and graphic explain the process behind correcting single-ventricle defects, also known as SVDs.This disorder happens when one of the heart's lower chambers doesn't work correctly, resulting in deoxygenated and oxygenated blood circulating the body rather than just the latter.

Roughly 1 in every 4,300 individuals in the US has mitochondrial disease

Roughly 1,000 to 4,000 kids are born with these conditions each year in the US though many of the diseases are fatal. Mitochondrial disorders often affect the organs that require the most energy, including the heart, brain, and muscles.

Peptides account for 31 of 370 new drugs approved by US FDA between 2016 and 2023

Among the approved peptide-based drugs is the first-ever treatment for Rett syndrome, a rare inherited neurologic disorder that leads to a progressive loss of motor skills and language. Peptides are particularly attractive for multiple reasons, including their ability to selectively bind to cellular receptors to either activate or inhibit their function.

Less than 1% of people globally have schizophrenia, a syndrome strongly linked to genetics

Schizophrenia's causes remain largely unknown, though scientists suggest it's caused by multiple factors. Its symptoms include disruption of thought processes rather than the exhibiting of multiple personalities. This brief video provides an overview of the condition.

She can't feel pain, hunger, or danger

Olivia Farnsworth, born with a rare chromosome 6p deletion, may be the only person known to lack pain, hunger, and fear responses. This overview explores her unique condition, the incredible incidents that revealed it, and how scientists hope her case could unlock new insights into human survival and sensory systems.

Breaking down various tongue disorders, from infections to genetics

Taste is one of our fundamental senses, but can be impeded by a wide variety of conditions including glossitis, angioedema, and black hairy tongue. Most are characterized by their color, shape, and sometimes change in function. Causes range from vitamin or mineral deficiencies to fluid accumulation, fungal infection, or more.

The ultrarare 'Er' blood type has been documented only about 40 times

In 2022, the tragic loss of a pregnancy led researchers to the discovery that the rare "Er" blood type could potentially cause a mismatch in blood types between mother and fetus during pregnancy, with devastating consequences. (Some users may encounter a paywall.)

There are hundreds of subtypes of cancer, making a universal cure nearly impossible

Cancer is an umbrella term for over 200 different diseases, each with its own subtypes, genetic mutations, and behaviors. This diversity means that a treatment effective for one cancer type or patient may be ineffective for others. Moreover, as tumors grow, their cells accumulate different mutations, creating subclones with unique characteristics.

Six-year-old boy in wheelchair surprises his family by walking at his graduation

The young boy was diagnosed with Noonan syndrome, a rare genetic disorder that impacts mobility and development, at just 2 months old. He usually needs a wheelchair or walker to get around, but he shocked and thrilled his parents by standing up to receive his kindergarten diploma.

Scleroderma, which causes skin to harden and scar, has no FDA-approved treatment

It's an autoimmune disease that disproportionately causes worse complications in African American people for unknown reasons. It causes the body to overproduce collagen after the immune system attacks the body's own connective tissue, leading to excess collagen deposits and restricted blood circulation as small blood vessels are damaged. It can damage various organs, including the lungs.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

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.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

Search a massive database of over 4 decades of clues from the TV quiz show 'Jeopardy!'

After her fellow cult members tried to kill her with an LSD-infused hamburger, one member of the Manson Family, the murderous cult led by Charles Manson, decided to testify against the group's leader.

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

A century of Billboard issues documenting the evolution of popular music.

View the ten deadliest tornadoes in US history.