Ricki Lewis

As if the waves of novel variants of "interest" and "concern" sweeping the planet haven't been enough, and we find versions of SARS-CoV-2 dodging in and out of species in a complex pattern of spillovers and spillbacks, we discover that it's even sneakier. Two new papers in Nature Communications, from a group at the Max Planck Bristol Centre of Minimal Biology, describe how the virus can differ genetically in different parts of the same host.

 

That may mean that if vaccines and treatments vanquish the virus in the respiratory tract, the pathogen might persist elsewhere. And the viruses in new places replicate and infect more vigorously, better able to elude our immune response. That's not good news as protection from vaccinations or having had COVID-19 wanes.

 

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

In honor of Rare Disease Day 2022, February 28th, I'm reposting a DNA Science story from nine years ago. February 16th was 12 years since Jane Mervar lost her young daughter to Huntington's disease (HD). Thank you

Jane for always sharing your story! (Updates are in parentheses.)

 

Looking back, signs that Jane Mervar's husband, Karl, had HD started when their youngest daughter, Karli, began to have trouble paying attention in school. Karl had become abusive, paranoid, and unemployable due to his drunken appearance. Karli, born in September 1996, was hyperactive and had difficulty following directions.

 

When by age 5 Karli's left side occasionally stiffened and her movements slowed, Jane began the diagnostic journey that would end with Karli's diagnosis of HD, which had affected her paternal grandmother.

 

Soon Karli could no longer skip, hop, or jump. New troubles emerged. "She had cold sweats, tachycardia, and chronic itching. She fell and suffered chronic pain. By age 6 she was losing her speech and became withdrawn," Jane recalls. Karli drooled and her speech became unintelligible. By age 7 her weight had plunged, and by age 8 she had developed pneumonia three times, due to difficulty swallowing. By age 9 she required a feeding tube, suffered seizures, and would go long periods without sleep.

 

An Adult's Disease in a Child

 

This isn't the way that a disease is supposed to run in families, striking child before parent. HD is regarded as a disease of adulthood, but in fact about 10 percent of people with the condition are under age 20 – they have juvenile Huntington's disease (JHD).

 

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

Lung transplants can be lifesaving for patients with end-stage lung diseases such as cystic fibrosis, COPD, pulmonary fibrosis, sarcoidosis, and pulmonary hypertension. Wait times for a lung vary from days to years, depending on a complex set of circumstances. In the US, 1400 adults and children await lungs at any given time. Less than a third of them will get one.

 

Position on the wait list is based on several factors: medical urgency, compatibility with an available lung, distance from the donor hospital, and pediatric status, according to the United Network for Organ Sharing.

 

An easily tested indication of whether a person's body will accept a transplanted organ is the ABO blood type. It doesn't have to match between donor and recipient, but it must be compatible. The A and B antigens (cell surface molecules) are sugars that are attached to proteins and fats on a cell's surface. The blood type is a single-gene trait.

 

Canadian researchers have tested a way to strip donor lungs from type A individuals of the A antigens that make them type A, using enzymes. Denuding the lungs essentially creates an "ABO-agnostic organ" that could, theoretically for now, nestle into the chest of a person with any ABO blood type and not induce rejection. The idea has been around for awhile without much success, but using a new pair of enzymes, discovered in the human gut microbiome in 2019, seems to improve on past attempts. 

 

"The treatment described here could further expand the pool of universal donor organs from the current 55% (blood group O donors) to over 80%. This strategy may greatly improve access and fairness of organ allocation," Aizhou Wang and colleagues from the University of Alberta write in Science Translational Medicine. The strategy could be applied to organs other than lungs. More than 100,000 individuals in the US await organs.

 

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

 

When Mark Twain wrote "Truth is stranger than fiction," he wasn't imagining people watching tales of an alien invasion and a pandemic unfold on their screens while hiding from a real pandemic. For a short span as 2021 became 2022, Apple TV+'s Invasion and HBOMAX's Station Eleven, each 10 episodes, briefly relieved reality. The first imagines planetary doom, while the second depicts humanity's recovery two decades after attack by a microscopic menace.

 

While thinking about both limited series a few days ago, I read a report in Nature that eerily evoked Mark Twain. It presents compelling evidence that SARS-CoV-2, the virus behind COVID-19, could change in one tiny but crucial part, in an instant, and transform itself into a pathogen perhaps worse than what we've already experienced. That truth would indeed be more terrifying than any fiction.

 

So here's a look at all three scenarios: two fiction, one not.

 

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

I have a special fondness for the yellow mealworm, Tenebrio molitor.

 

As a child, I fed the mealworm stage of this beetle to my pet chameleon.

 

As a teen, I babysat for a family that owned a pet shop. The house was filled with animals, and I was thrilled to be there. That is, until right before bedtime.

 

As I was trying to get the kids upstairs, a monkey grabbed a can, leaped atop a curtain rod, whipped the top off, and happily sprayed dozens, perhaps hundreds, of writhing, fat, pale mealworms all about the living room. It was great fun collecting them.

 

Then a few days ago I got a news release from Paris-based Ynsect. The company's goal: to farm massive numbers of yellow mealworms as food for humans. And I instantly remembered the creatures festooned around that long-ago living room.

 

Ynsect's good news was that the yellow mealworm's genome had finally been sequenced. Thank goodness! It was a tough one to crack.

 

Eating Mealworms

 

Farming yellow mealworms for food makes sense.

 

To continue reading go to my blog DNA Science.

Just as we thought Omicron was rolling across the US and into oblivion, a new "subvariant" has arrived and is, again, taking over. At the same time Moderna is announcing dosing of the first participant in its phase 2 study of an Omicron-specific booster. But Omicron's evolution wasn't unexpected – the World Health Organization's recent update cites four lineages of Omicron, dubbed BA.1 through BA.4.

 

"So it goes," to quote Kurt Vonnegut in Slaughterhouse Five. But that statement was in response to death among the Tralfamadorians – not the robust activity of a tiny virus.

 

It seems to me that the continual categorization of SARS-CoV-2 reflects the human urge to group, categorize, and name things to help us understand them. I think the situation is eventually going to dissolve into a continuum of genetic flux as the tango of mutation and selection continues. That's what nucleic acids do.

 

Since it still new days for Omicron 2.0, here's a snapshot:

 

WHAT WE KNOW 

 

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

In these days of the never-ending pandemic, other health problems continue to take a backseat. That's especially true for the 7,000 or so rare diseases that collectively affect only one in ten people, while the number of COVID fatalities in the US nears the million mark. 

 

Although some clinical trials for rare disease treatments have stalled, they'll resume once COVID settles into some version of endemicity. More than 60 cell and gene therapy FDA approvals are expected by 2030, according to the Massachusetts Institute of Technology's New Drug Delivery Paradigms Initiative. They range from RNA-based drugs to gene therapies to CRISPR fixes.

 

Rare diseases tend to strike the youngest. Clinicaltrials.gov hints at what's to come.

 

CRISPR is tackling sickle cell disease and thalassemia, while antisense technology is being tried for Duchenne muscular dystrophy. Searching for "gene therapy" brings up 5000 hits for this older approach, many targeting childhood diseases.

 

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

Many years ago, a dear friend took me to the Detroit zoo to see the Hippoquarium. Much to my delight, the resident hippo positioned her rear to the glass of the enclosure and let loose, her whirring tail distributing the intestinal contents like blowing on an open milkweed pod.

 

A few years later I saw the same demonstration at the Tampa zoo, a hippo's whirligig-of-a-tail in action.

 

Hippo Microbiomes

 

Recently, researchers from the US and Kenya described in Scientific Reports their investigation of the ejection of hippo feces into the pools of the Serengeti's Mara River. A more natural environs than a zoo, the river is home to more than 4,000 hippos wallowing in some 170 hippo pools in the Kenyan part of the territory.

 

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

An end may be in sight. For the first time since the pandemic began, I listened to a press briefing from medical experts that did not give me nightmares.

 

It was December 11, 2022, the weekly zoom from the Massachusetts Consortium on Pathogen Readiness (MassCPR). The group of eloquent experts formed at the dawn of the pandemic. They've held sporadic briefings for journalists over these many months, ramping up to weekly as Omicron loomed in early December.

 

From JAMA to MassCPR

 

At the beginning, I was a fan of the online Conversations with Howard Bauchner, who was then editor-in-chief of the Journal of the American Medical Association. Dr. Bauchner's laid-back manner got the superstars of the pandemic – from Anthony Fauci to Rochelle Walensky to Paul Offit – to relax, in an environment far from Clorox-pitching presidents and the like. Those were the days when the experts talked of the goal of herd immunity. I suspect none of them imagined that so many people would shun life-saving vaccines and even make the decision political, endangering us all and providing fertile ground for Omicron and the other variants to evolve, emerge, and threaten us in new ways. I know it blindsided me.

 

 

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

For many years I've ended editions of my human genetics textbook with a request for students to email me to share their thoughts on what they'd learned. Only one student has ever contacted me.

 

Emmanuel Zoboi Gokpolu was in high school in Monrovia, Liberia, when he emailed me at the end of his genetics course, in 2007.

 

My husband Larry and I quickly developed a friendship with Eman; he calls us Mom and Dad. We sent him a package of Obama tee shirts, which he distributed to his family. Free people of color from the US founded an independent Liberia in 1847, so there was a connection.

 

I recognized something special in Emmanuel right away, a love of biology and a compelling interest in health care and helping people. Larry and I supported him through college and then we encouraged him to go to medical school – fulfilling a dream of mine (bad chemistry grades kept me from applying).

 

Med school in Liberia was going well, until Ebola struck in 2014. With half the instructors dying and classes halted, Eman led medical students in carrying out public health measures. He organized a group called "Determined Youth for Progress" to sensitize rural communities to Ebola awareness and prevention measures, sent text alerts, and did contact tracing.

 

He told his story during the Ebola crisis here at DNA Science, in Eman's Emails from Liberia: Through September and then Eman Reports from Ebola Ground Zero. During that time, instead of paying his tuition, we sent support for gloves, detergent, bleach, and long sleeve shirts to keep him and his family as safe as possible.

 

Reading over that first post about Eman now gives me chills, in the context of COVID. Eman wrote on August 6, 2014:

 

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