Ricki Lewis

Links between environmental exposures and increases in cancer rates take time to emerge. They range from community-wide disasters, like the 25-year dumping of carcinogens into the former Love Canal in Niagara Falls that caused kidney and bladder cancer, to associations that seem obvious in retrospect, like smoking and lung cancer, sun exposure and melanoma. My breast cancer might have arisen from in utero exposure to diethylstilbestrol (DES), a drug given to pregnant women in the 1950s to calm morning sickness.

The hallmark of an environmentally-triggered cancer is a sudden increase in incidence (rate of new cases over time) and prevalence (total cases at a specific time) of a particular type of cancer that parallels an increase in exposure to a specific chemical, or class of chemicals. A genetic change would take much longer to manifest.

A classic illustration of an environmentally-caused cancer is the increase in lung cancer in the 1950s that followed the pervasive cigarette smoking among the post-World-War-II generation. It was a time when cigarette ads dominated TV, airplanes stunk of stale smoke, and the habit was actually considered attractive. Many people, especially women, felt pressured to smoke to be accepted.

To continue reading, go to DNA Science, where this post first appeared.

I fear that 2025 is ending with a tragic irony: the dismantling of progress in biomedical research, as infectious diseases return and resurge. Arrogance and ignorance are proving to be more dangerous pathogens than bacteria and viruses.

So I thought I'd close out the year with an uplifting look at a funding source not threatened by the current administration: the California Institute of Regenerative Medicine, aka CIRM.

Two Decades of Funding Research, Needed More Now Than Ever

CIRM was born 20 years ago, when 59 percent of California voters approved Proposition 71, and reaffirmed it in 2020. Since then, the taxpayer-supported organization has provided more than 1400 grants, totaling nearly $4 billion.

Grants support all stops on the journey from initial idea to delivering a new treatment. That means funding basic research at universities and supporting education, collaboration, scientific and medical meetings, as well as manufacturing facilities, clinics, hospitals, and community outreach programs.

To continue reading, go to DNA Science, where this post first appeared.

Pluribus, Apple TV+'s sci fi series that just concluded its first season, is a clever take on the alien invasion theme, from Vince Gilligan of Better Call Saul fame. I enjoyed it, but wish the writers had consulted a scientist or two in creating the backdrop of genetics and cell and molecular biology.

The series honors Isaac Asimov's science fiction law of "change only one thing." An alien RNA virus infects people, robbing them of their individuality and their humanity as a "hive mind" forms across the planet, with the exception of thirteen individuals. But the writers demonize RNA (don't we have enough of that?) while conflating egg cells with stem cells.

Does accuracy really matter for plausibility in a sci-fi plot? I suspect I'm in the minority when I say yes, it does.

To continue reading, go to DNA Science, where this post first appeared.

One of my greatest joys in revising my human genetics textbook is adding treatments for genetic diseases that have been FDA-approved since the last edition. The list has grown quite a lot since I finished the last revision as the pandemic finally faded away, and certainly since my gene therapy book was published in 2013. And so I was thrilled a few days ago when the father of a boy who had Menkes disease reposted my DNA Science blog from 2021, which described the rare disease, the clinical trial, and the family's participation.

The "new" treatment – many kids with Menkes have been part of the clinical trial for years – is a simple injection administered daily under the skin that delivers copper, which the body cannot process from food. It's not gene therapy, nor gene editing, nor magic – it is a sensible, decades-old strategy of finding a way around a biochemical glitch. Specifically, the drug Zycubo, aka copper histidinate, is a copper replacement therapy. Cyprium Therapeutics developed the long-awaited treatment.

To continue reading, go to DNA Science, where this post first appeared.

With the pandemic past and vaccine-preventable infectious diseases creeping back, we don't think often about syphilis.

A new report in Science, from Davide Bozzi of the University of Lausanne, Switzerland and colleagues, uses DNA evidence to rewrite what we thought we knew about how and when European explorers brought the sexually transmitted infection here. It turns out, they likely didn't.

The genome sequence from a recently-discovered sample of a close relative of the modern bacterium that causes syphilis, in Sabana de Bogotá, Colombia, backdates the origin of the STI in North America to much earlier than previously thought. So European explorers might have picked the STI up here and brought it home, where it spread in the late 15th century.

The bacterium Treponema pallidum causes syphilis, which belongs to a group of infectious diseases caused by spiral-shaped bacteria (spirochetes) that includes yaws, bejel, and pinta. People have suffered with these diseases for thousands of years, but evidence from human remains is sparse, because the bacteria crumble bones. Obtaining long enough DNA molecules to overlap them and deduce the genome sequence from ancient microbial pathogens has been difficult.

To continue reading, go to DNA Science, where this post first appeared.

As Thanksgiving approaches, thoughts turn to turkeys. This year, the holiday comes soon after announcement of the first steps in recreating dodo birds – could we breed "de-extincted" dodos for Thanksgiving?

Do the math.

The extinct birds grow up to 50 pounds, and people consume about 1.5 pounds of turkey for Thanksgiving, less if side dishes are plentiful. So a single dodo could feed perhaps 35 or so people, accounting for the inedible parts. Both birds grow to about three feet tall, but a modern turkey, especially a wild one, is trim compared to a dodo, which is basically an overgrown pigeon. A Dutch sailor in 1662 supposedly described the soon-to-be extinct bird as a "kind of very big goose."

To continue reading, go to DNA Science, where this post first appeared.

Genetics is a field rich in numbers and patterns, reaching back to Gregor Mendel's crosses of pea plants with distinguishing characteristics that revealed the two basic laws of inheritance.

At a microscopic level, genetics is informational, a series of languages: a DNA sequence is transcribed into an RNA sequence, which is then translated into a sequence of amino acids comprising a protein molecule. The suite of proteins, with abundances ebbing and flowing as patterns of gene expression change in response to the environment, provides our traits, our abilities, and the myriad metabolic reactions that keep us going.

Because genetics is so highly informational, it is a natural target for artificial intelligence. AI can speed, enhance, and extend what we know about the meanings in our genes, transcending what we deduce from far simpler data. It digests (trains on) massive amounts of data, stores and analyzes them, then makes connections and provides insights beyond what a human mind could do.

A Very Brief History of AI

To continue reading, go to DNA Science, where this post first appeared.

For the first time in 35 years of writing and revising my textbook Human Genetics: Concepts and Applications, I'm happy to report good news – real progress, and not hype.

The strides in 2025 range from effective gene therapies and drugs for devastating neurological conditions to a novel new painkiller. Here's a closer look at the good news!

Gene Therapy for Sanfilippo Syndrome
DNA Science first covered the story of Eliza O'Neill in 2014, here, when the parents of four-year-old Eliza, a vivacious, active, and adorable little girl, learned that she had inherited the rare brain condition Sanfilippo syndrome type A.

Her dad Glenn O'Neill remembered:
"'We found out the terrible news today. For now, I want to focus on her wonderful personality and life every day. One of my goals is to keep her happy and smiling for as long as possible. I love her so much.'

To continue reading, go to DNA Science, where this post first appeared.

The toppling of health care in the US has begun, and I fear will reverberate for decades to come. It is beginning with vaccine refusal.

• "2 Kentucky Infants Die of Pertussis as Cases Rise" (American Academy of Pediatrics)

• "Two Infants Die of Whooping Cough in Louisiana as Cases Climb Nationally" (CNN)

• "Whooping Cough is Surging in the US – What You Need to Know" (New York Academy of Sciences )

Ahead of pertussis is the more-deadly measles. It's back, and mostly among the young and unvaxxed. Details are here, from what's left of the CDC.

While vaccine-preventable deaths get attention, a perhaps larger problem looms: the decimation of preclinical research. Like pulling out a critical block in a game of jenga, cutting funding for research using non-human animals will ultimately topple the foundations of clinical trials that test new treatments in people.

To continue reading, go to DNA Science, where this post first appeared.

It's rare that clinical trial findings are as exciting as what biotech company UniQure has just announced. The company is based in Amsterdam and Lexington, Mass.

Early results, after three years of a clinical trial conducted in the US, UK, and Europe, suggest that the treatment, for now called AMT-130, significantly slows the progression of Huntington's Disease (HD). And although when I originally wrote this post in September it looked like the treatment could be available in the US as early as 2026, since then what is left of the Food and Drug Administration has cast doubt on the significance of the trial results, according to a Uniqure news release. But the treatment will be available elsewhere, and in the US when experts return to the agency, eventually.

A Variation on the Gene Therapy Theme: MicroRNAs
The strategy uses microRNA technology to stamp tiny pieces of RNA onto the mRNA molecules that carry the information in the overextended gene behind HD, which encodes a protein called huntingtin. The oversized protein gums up parts of the brain that are critical for movement.

To continue reading, go to DNA Science, where this post first appeared.