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Ricki Lewis

Genetic Linkage

Supreme Court BRCA Decision: Use Correct Terminology!

June 14, 2013
Tags: Supreme Court, BRCA1, BRCA2, gene patents, DNA, composite DNA
(credit: Dept of Energy)
Earlier today, my “in” box began to fill with info from everyone I’ve ever met letting me know that the Supreme Court had ruled on the Myriad case about patenting the breast cancer genes BRCA1 and BRCA2. I also received a dozen pitches from PR people offering me all manner of instant interviews with lawyers, doctors, bioethicists, and health care analysts.

No one offered me an interview with a geneticist – a person who knows something about DNA. So being such a person myself, I decided to take a look at the decision. And I found an error right smack in the opening paragraph: Read More 
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Juvenile Huntington's Disease: The Cruel Mutation

June 3, 2013
Tags: Huntington's disease, rare disease, Woody Guthrie, CHDI, HDSA, Genetics, triplet repeat mutation
Jane and Karli Mervar
Looking back, signs that Jane Mervar’s husband, Karl, had Huntington’s Disease (HD) started about 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. The little girl, 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 the little girl’s paternal grandmother.

Soon Karli could no longer skip, hop, or jump. And new troubles emerged. Read More 
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A Little Girl with Giant Axons, a Deranged Cytoskeleton, and Someday Gene Therapy

May 16, 2013
Tags: GAN, gene therapy, Alzheimer's disease, Parkinson's Disease, The Forever Fix
Hannah, 7 years old (Dr. Wendy Josephs)
“When you hear hoof beats, think horses, not zebras.” So goes the mantra of first-year medical students. If a common disease is a horse and a rare disease a zebra, then giant axonal neuropathy (GAN), with only 50 or so recognized cases worldwide, is surely a unicorn.

Five years ago this week, 9-year-old Hannah Sames of Rexford, New York, who lives near me, received a diagnosis of GAN, a disease much like amyotrophic lateral sclerosis. And this month, thanks in part to the herculean fundraising efforts of Hannah's Hope Fund (HHF), the cover and lead article of the Journal of Clinical Investigation reveal most of the story behind the devastating inherited disease, with repercussions that will reach far beyond the tiny GAN community. Read More 
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Celebrating Gleevec – and Basic Research

May 10, 2013
Tags: chronic myeloid leukemia, Philadelphia chromosome, tyrosine kinase inhibitor, Gleevec, cancer, translational medicine, chimeric antigen receptor
Peter Nowell and David Hungerford began the work that led to the successful cancer drug Gleevec (Penn Medicine)
When 23-year-old Glamour magazine editor Erin Zammett Ruddy went for a routine physical in November 2001, she expected reassurance that her healthy lifestyle had been keeping her well. After all, she felt great. What she got, a few days later, was a shock. Instead of having 4,000 to 10,000 white blood cells per milliliter of blood, she had more than 10 times that number – and many of the cells were cancerous.

Erin had chronic myeloid leukemia (CML). Two years before her diagnosis, CML was a death sentence. But the drug Gleevec saved her and many others. It offers perhaps the best example of translational medicine. Read More 
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The Sickle Cell/Malaria Link Revisited

April 25, 2013
Tags: DNA Day, World Malaria Day, Anthony Allison, malaria, sickle cell disease, balanced polymorphism, DNA Science
Eman is a medical student in Liberia.
Today is both DNA Day and World Malaria Day. As I was pondering how to connect the topics, e-mail arrived from my “son,” a medical student in Liberia. He had malaria, again, and this time it had gone to his brain.

I “met” Emmanuel in 2007, when he e-mailed me after finding my contact info at the end of my human genetics textbook, which he was using in his senior year of high school. He is my personal link between DNA Day and World Malaria Day. But the dual commemoration also reminds me of the classic study that revealed, for the first time, how hidden genes can protect us – that carriers of sickle cell disease do not get severe malaria. Read More 
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DNA Day: 20 Years of Writing a Human Genetics Textbook

April 19, 2013
Tags: human genome, DNA, Genetics, Gregor Mendel, cystic fibrosis, textbook
10 editions of my textbook chronicle the evolution of genomics
This month we celebrate the DNA anniversaries: unveiling of DNA’s structure in 1953, and the human genome sequence in 2003.

From now until DNA Day, April 25, bloggers will be worshipping the human genome. Nature will offer podcasts (“PastCasts”) and last week, Eric Green, director of the National Human Genome Research Institute, spoke to reporters, summarizing the “quantitative advances since the human genome project.”

It’s also the 20th anniversary of my non-science majors textbook, Human Genetics: Concepts and Applications. Writing the 10 editions has given me a panoramic view of the birth of genomics different from those of researchers, physicians, and journalists. Here are a few observations on the evolution of genetics to genomics, as I begin the next edition. Read More 
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LGIS (low glycemic index soup/stew)

April 15, 2013
Tags: glycemic index, Diabetes, blood sugar, Recipes
Careful combining of ingredients keeps blood sugar down.
To help people with high blood glucose, I investigated the glycemic index for many vegetables, and invented something actually palatable, Low Glycemic Index Soup/Stew (LGIS). Be liberal with spices (I use Greek mix), and it's great. Tasty, easy, filling, cheap, easily made vegetarian, and it lowers blood sugar 2 hours post-prandial to about 110!

In crockpot:

celery (handful of small pieces)
1 big can of tomatoes, squished, or fresh
a few baby carrots cut up (limit these)
1 small zucchini cut into small cubes
1 whole zucchini, smashed after it softens
1 very small cut up onion
handful of fresh green beans, cut into pieces
1 cup broccoli + cauliflower pieces (from frozen mix)
lots of small pieces of bok choy
½ can chick peas (or whole can for stew) (lentils ok too)
1 pound beef in small cubes
veggie broth
beef broth
parsley (a bit)
spinach (handful or more)
cabbage OK but it gets a little smelly

DO NOT USE
Root vegetables – no parsnips, turnips, leeks, potatoes
More than 1 onion
More than 4 baby carrots
Beans (other than green and chickpeas)
Peas

FOR VEGETARIANS just leave out the beef! Read More 
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A Spleen Gene – And A Ribosomal Surprise

April 14, 2013
Tags: asplenia, spleen gene
(Gray's Anatomy)
The spleen is a very unappreciated body part. The Talmud considered it the “organ of laughter,” whereas the ancient Greeks equated it with melancholy. Today it’s sometimes used to mean anger.

When a spleen bursts, spewing all manner of blood cells, we take it out – as happened to Katniss Everdeen in the third installment of The Hunger Games and to Jack Ryan’s daughter in Tom Clancy’s Patriot Games. But starting life without a spleen is a whole different story. It’s deadly.

“The spleen is not the brain. No one thinks it’s very important,” says Alexandre Bolze, PhD, a postdoctoral researcher at Rockefeller University. His discovery of what causes a person to lack a spleen, reported April 11 in Science Express, has implications far beyond a ridiculed body part. Read More 
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Genetic Modifiers: Healthy Mutants Fuel Drug Discovery

April 12, 2013
Tags: BRCA1, BRCA2, incomplete penetrance, 23andMe, exome, genome, genetic counseling, amyloidosis, Alzheimer, Parkinson
Disease-causing mutations in healthy people suggest new drug targets. (NHGRI)
I’m uneasy counseling a patient for mutations in the BRCA1 or BRCA2 cancer susceptibility genes. Typically, she’ll have a “first degree relative” – usually a mother or sister – with a related cancer, or might even have a test result in hand. This happened a week ago.

FUZZY GENETIC INFORMATION
My patient comes from a long line of female relatives who’d died young from breast or ovarian cancer. She’s already been tested and knows she has a BRCA1 mutation. Will she get the family’s cancer? Knowing would enable her to decide whether and when to undergo surgery to remove her breasts, ovaries, and uterus. Read More 
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Incidental Findings from Genome Sequencing – Nuances and Caveats

March 24, 2013
Tags: genome, DNA, incidental finding, 23andMe, bioethics
A genome sequenced to investigate one disease may reveal another.
You have your genome or exome (the protein-encoding part) sequenced to help diagnose a puzzling set of symptoms, and something totally unrelated, and unexpected, turns up – a so-called “incidental finding.”

Surprises, of course, aren’t new in medicine. The term “incidental finding” comes from “incidentaloma,” coined in 1995 to describe an adrenal tumor found on a scan looking for something else. I had one -- a CT scan of my appendix revealed a polycystic liver. A friend had it much worse. She volunteered to be a control in an Alzheimer’s imaging trial, and her scan revealed two brain aneurysms!

Geneticists have long expected an avalanche of incidental findings from clinical (exome or genome) sequencing. Read More 
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