Ricki Lewis

Certain things have a natural order. Breakfast before lunch. Infancy before adolescence. Autumn before winter.

So I was surprised to read an article last week in Science Translational Medicine about experiments at Duke University treating cancer in human cells and in mice with an engineered poliovirus, when the television news show 60 Minutes had reported on four patients receiving the treatment for brain tumors back in 2015. Doesn’t preclinical work – cells and animal models – come first?

I decided to investigate. Read More 

The intense nausea that follows drinking alcohol for people with a certain gene variant may become the basis for a gene therapy to prevent alcohol use disorder, the new medicalized term for alcoholism. It would work much like the drug Antabuse, used for more than half a century, but on a less fleeting permanent basis.

Cells process ethanol, the type of alcohol in beverages, in two steps, each controlled by an enzyme. First ADH (alcohol dehydrogenase) speeds the reaction of ethanol to form acetaldehyde. Then ALDH2 (aldehyde dehydrogenase 2) breaks down the acetaldehyde into acetic acid, aka vinegar.

But if that second enzyme isn’t working well, acetaldehyde builds up, and nausea ensues. Because throwing up is so unpleasant, individuals who tend to upchuck after drinking avoid alcohol. Read More 

Whenever I work on a new edition of my human genetics textbook and reach the section on eugenics, at the end of an evolution chapter, I’m relieved that it’s history. But this summer, as I wrapped up the 12th edition, the eugenics coverage took on a frightening new reality. Read More 

Last week I gave an invited lecture at Georgia College, “Gene Therapy: A Forever Fix”?

I’ve given the talk many times, since my book The Forever Fix was published in 2012, but this was the first time I didn’t cry. That’s because the first children who have received gene therapy are showing signs of having a future.  Read More 

Willow is a beautiful name. Meaning slender and graceful, like the tree, it evokes images of a little girl running through the woods with streams of hair behind her. But Willow Cannan, who lives in Mississippi with her parents and two older sisters, can’t run or do very much on her own.

A MASTER MOLECULE MISSING

Willow was born on August 21, 2013. At first she seemed fine, except for difficulty nursing.

“Nothing in itself was significant, but a combination of things over time got worse. She crawled a little late. She did walk, but late, at 18 months. She had frequent ear infections, and dry skin that was very bad on her back and her scalp. And she never talked. No words, not even dada. She just made a few sounds,” recalled her mother, Amber Olsen.

The clues started to accrue between 18 and 24 months, when speech therapy didn’t help. Was the problem fluid in her ears, or enlarged adenoids? Willow had her adenoids out the day after she turned 2.

Amber and her husband Tom Cannan probably didn’t know it at the time, but they were about to start the diagnostic odyssey that millions of rare disease families share. It starts with convincing a pediatrician to look beyond the “horses” that are the common childhood conditions to recognize that a child is a zebra or unicorn, with a collection of rare peculiarities that might actually be trumpeting an underlying genetic glitch. Read More 

A curious thing happened when researchers at Georgia Tech used modern human genome sequences to look back at the possible health of our long-ago ancestors – they found that while the Neanderthals and Denisovans of 30,000 to 50,000 years ago seemed to have been genetically sicker than us, “recent ancients” from a few thousand years ago may actually have been healthier. Their paper, “The Genomic Health of Ancient Hominins,” is published in Human Biology.

How could that be? Perhaps drugs and procedures that enable us to live with certain conditions also perpetuate gene variants that would otherwise sicken us enough to not reproduce. We pass on those genes and inexorably weaken our global gene pool. Read More 

In response to media items about white nationalists disappointed in their DNA ancestry testing results, I read the paper on which the reports were based, and wrote "Memo To White Nationalists From A Geneticist: Why White Purity Is A Terrible Idea," for a new website, Science Trends. The post is here.  Read More 

Charlie Gard would have turned one year old last week.

Two days before the British infant died of a mitochondrial disease on July 28, a short article in MIT Technology Review teased that Shoukhrat Mtalipov and his team at Oregon Health & Science University and colleagues had used CRISPR-Cas9 to replace a mutation in human embryos, a titillating heads-up that didn’t actually name the gene or disease.

A week later, Nature published details of what the researchers call gene correction, not editing, because it uses natural DNA repair. I covered the news conference, with a bit of perspective, for Genetic Literacy Project and Medscape Medical News.

Might gene editing enable Charlie’s parents, who might themselves develop mild symptoms as they age, to have another child free of the family’s disease? Could anything have saved the baby? Read More 

A hypothetical heterosexual couple living in the US or UK takes tests to learn if they are carriers of the more prevalent recessive diseases. They’re relieved to find out that cystic fibrosis (CF) isn’t something they need worry about passing to their children – neither has any of the few dozen mutations the test panel includes.

The couple do not carry the most common 32, 106, or even 139 disease-causing mutations in the CFTR gene, the number depending upon the testing lab. But that could be a problem – a false negative – if the woman and man are anything other than non-Hispanic whites.

More than 2,000 variants (alleles) of CFTR are known, and their prevalence varies in different populations. That’s not because DNA recognizes the race or nationality of the person whose cells it’s in, but because of how we choose our partners. Read More 

I set a high bar for writing about mouse studies. I don’t include them in my textbooks or news articles, and only rarely blog about them. But when experiments in mice shine a glimmer of hope on a horrific illness with a long history of failed treatments, I pay attention. That happened last week for a report on editing out of mice the human version of the mutant Htt gene that causes Huntington disease (HD), published in the Journal of Clinical Investigation. Read More