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Genetic Linkage

Revising a Human Genetics Textbook and Countering Vaccine Hesitancy

I haven't thought or written much about human genetics since COVID hit, instead cranking out articles about the novel coronavirus and the repercussions as it evolves and spreads.

 

Now it's time to revise my human genetics textbook. The thirteenth edition of Human Genetics: Concepts and Applications came out in September 2020. I'd signed off on the final page proofs that April, back when New York City was the COVID epicenter for the US. I only had time to swap in a SARS-CoV-2 photo for one of Zika virus, and replace a flu paragraph with what we knew about COVID at that time.

 

With each revision, I think back on how the field has changed in the 20 years since the first edition. That typically means updating coverage of genetic tests and technologies – topics like cell division, Mendel's laws, DNA and RNA and protein, evolution and populations – remain the same. This time though, in the face of vaccine hesitancy, the importance of understanding basic genetics is much more compelling. The context: the vaccines work by taking advantage of the way that genes control protein production.

 

To continue reading go to DNA Science, my blog at Public Library of Science.

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The Treatabolome Will Shorten Diagnostic Odysseys for Rare Diseases

(Solve-RD)

The journey of naming an odd collection of symptoms is called, for good reason, the diagnostic odyssey. It can take years for gateway health care providers and then sequences of siloed specialists to synthesize clinical findings and a family's observations into a diagnosis.

 

Consider Hannah's Sames' journey. Hannah had gene therapy for giant axonal neuropathy in 2016, and I tell her story in my book The Forever Fix: Gene Therapy and the Boy Who Saved It. Hannah was diagnosed at age 3; she just attended her junior prom!

 

The first sign of Hannah's condition, in retrospect, was her tight curls, the consequence of buildup of an abnormal protein, gigaxonin. The second sign was her odd gait as a toddler. A pediatrician, orthopedist, and podiatrist had no idea that the feathery filaments of abnormal gigaxonin were already distorting the motor neurons whose axons stretched down the little girl's legs.

 

To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared.

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How Viral Variants Arise

The public has had a crash course in virology. But sometimes media coverage spews jargon so fast, often without definitions or descriptions, that I wonder to what degree readers or viewers know what terms like antibody, cytokine, or mRNA actually mean.

 

"Variant" is especially problematical, when coming after "viral," because it has a plain language meaning too – variation on a theme, something just a little bit different from what we're used to. But during an epidemic, a small genetic change can have sweeping consequences, fueling a pandemic.

 

Mutations Build Variants

Variants of SARS-CoV-2 – the COVID virus – are sets of mutations. A mutation is a specific change in a specific gene.

 

Different variants have some mutations in common, so it can get confusing. For example, three variants circulating in India each has 6 or 7 mutations, three in common. The first and second variants that were discovered each has a unique mutation, but the third variant is a subset of parts of the first two. Got that?

 

To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared.

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The H5N8 Bird Flu and Why We Should Pay Attention

Before COVID, reports of a new bird flu trickling or even sweeping out of Asia didn't garner much attention. That's certainly changed. So when two members of the China Novel Coronavirus Investigating and Research Team, who co-authored the first warning of what was to come in February 2020 in The New England Journal of Medicine, sound a new alarm, maybe we should listen.

 

In a short Insights Perspective published in Science, "Emerging H5N8 avian influenza viruses," Weifeng Shi and George Gao make the case for concern that a bird flu now in more than 46 countries across Europe, Asia, and Africa has jumped to humans. Only seven poultry farm workers in Russia were reported to have gotten sick, while trying to contain an outbreak among their feathered charges. But there must have been a time, in the fall of 2019, when COVID, too, had sickened only a few people.

 

An avian influenza virus would need to pass easily from person-to-person to seed a pandemic in people, like SARS-CoV-2 does. That's unlikely, but as we've learned, not impossible.

 

 

To continue reading, go to my DNA Science blog at Public Library of Science, where this post first appeared.

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Live to 150? That’s what some AI algorithms claim is possible. What does the science say?

We're obsessed with aging. 

 

In the quest to prolong life while remaining healthy, people have tried everything from turtle soup to owl meat to drinking human blood.

 

Russian-French microbiologist and Nobel Prize winner Ilya Mechnikov believed that a person could live 150 years with the help of a steady diet of milk cultured with bacteria. (He died at 71.)

 

It's a favorite topic of Hollywood. From Cocoon to Death Becomes Her to Chronos, the quest to extend our limited time on this planet has been a favorite focus of science fiction. Now it's edging closer to science fact.

 

A new report in Nature Communications from researchers at artificial intelligence company GERO.AI indeed points to a maximal human lifespan of 150. And they've pioneered a metric that might one day pop up on a smartphone to indicate an individual's state of aging – something more meaningful, in terms of future health, than counting gray hairs or celebrating birthdays.

 

To continue reading, go to Genetic Literacy Project, where this post first appeared.

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The age of genetically-enhanced children is approaching. Novelist Kazuo Ishiguro imagines a have-and-have not future, and it’s not pleasant

Biotech interventions to help sick children—like gene therapy—are approached with supreme caution. If a treatment has a reasonable chance of working, and especially if there aren't alternatives, potential benefits might clearly outweigh the risks, and favor running a clinical trial. 

 

But genetic modification of sperm, eggs, or embryos is a different story, even with a therapeutic goal (see GLP Ricki Lewis' Designer babies? US scientists swap DNA in embryos, replacing mutation that causes heart problems). Scrutiny is even more intense if the intervention aims not to heal or prevent illness, but to genetically enhance children, striving to somehow "improve" them.

 

Could genetic modification endow a child with high intelligence, facility with learning languages, musical or artistic ability, or mathematical genius? And what would happen to a society in which wealth determines whose children are enhanced?

Gene editing creates class-ism

 

Kazuo Ishiguro's new novel, Klara and the Sun, imagines a world in which some children are rendered exceptionally intelligent with genetic modification. The British author, recipient of the 2017 Nobel Prize in Literature, also wrote the 2005 dystopian masterpiece Never Let Me Go (and 2010 film), set at an English boarding school in the 1990s. In that alternate reality, people are cloned to provide organs for the wealthy, perishing proudly in young adulthood when they run out of spare parts.

 

To continue reading, go to Genetic Literacy Project, where this post first appeared.

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Wishbone Day Raises Awareness of Osteogenesis Imperfecta

Today, May 6th, is Wishbone Day, to raise awareness about osteogenesis imperfecta (OI).

 

Also known as "brittle bone disease," OI is a consequence of mutations that disrupt the highly organized structure of collagen, a major component of connective tissues. Collagen accounts for more than half the protein in bone and cartilage, and is also part of skin, ligaments, tendons, and the dentin of teeth.

 

Because OI is due to a deficit of collagen, eating more calcium doesn't help – the advice given to members of a family I wrote about here. Before many genes behind OI were identified, some parents of children with OI were suspected of child abuse, especially when a second child had fractures too.

 

A Collection of Collagen Conditions

 

To continue reading, go to DNA Science, my blog at Public Library of Science.

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Genomics to the Rescue for Sumatran Rhinos

Kertam, a Sumatran rhinoceros

Sumatran rhinoceroses are solitary creatures that browse the dense rainforests of Borneo and Sumatra, living in small, scattered, shrinking groups. Taking a census is challenging, although they "sing." It isn't known how many of them exist, exactly, but the number is small.

 

A multinational research team has unearthed clues in the genomes of 21 of the animals, five "historical" from the Malay Peninsula where they are extinct, and 16 modern genomes from the remaining populations on Sumatra and Borneo. "Genomic insights into the conservation status of the world's last remaining Sumatran rhinoceros populations" appears in Nature Communications.

 

 

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

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Expand Rapid Testing to Help Counter COVID Variant Spread, Says Harvard Epidemiologist Michael Mina

I just returned from an enlightening trip to CVS, to photograph Abbott Lab's at-home rapid antigen test for COVID, BinaxNOW. It became available at three major drugstore chains on April 19.

 

"Do you have the rapid COVID test? The at-home one?" I asked the woman behind the pharmacy counter.

Deer-in-the-headlights.

 

Fortunately, the pharmacist behind her overheard. "Not only don't we have it, but we don't know when we'll be getting it." I wasn't too surprised; I live in a small town.

 

So I got on line to buy some vitamin gummies, appropriately socially distanced, and saw to my immediate left a prominent display of items that everyone should have to prevent COVID: wipes, hand sanitizer, gloves, masks. They provided a backdrop to a stack of 6 boxes of – BinaxNOW!

 

Of course, a detection test to see if you've been infected is not at all the same thing as a preventive measure. So I circled back to the pharmacy, and within seconds of notifying the pharmacist that the tests were indeed available, an angry summons for the manager bellowed out over the loudspeaker.

 

Oops.

 

 

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

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Would you agree to be infected with COVID for science? Intentional 'challenge' studies underway as researchers explore new vaccines and treatments

(hVIVO)

Lauren Thomas, who just turned 26, is trying to get into a clinical trial at the University of Oxford, where the American is in a master's program in data science. She's seeking to be intentionally reinfected with SARS-CoV-2, the virus that caused her bout with COVID-19 back in October.

 

Thomas had a mild case – just a fever. So now she's volunteering to help researchers understand the aftermath of infection, waiting to hear whether she'll get into the clinical trial. In the meantime, she's an organizer for 1daysooner, a non-profit advocacy group for people wishing to participate in research and launched in April 2020. A major focus has been joining clinical trials for COVID vaccines.

 

Why would anyone sign up for a second encounter with the virus that has shattered the world?

 

To continue reading, go to Genetic Literacy Project, where this post first appeared.

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