Ricki Lewis's Blog, page 40
November 11, 2017
What�s In A (Disease) Name?
Marc Pieterse was angry.
His son Vincent�s unusual features � long, thick eyelashes; low-set ears; extra teeth; autistic behaviors; brittle hair; flat back of the head; hearing loss; developmental delay � had led Marc, an engineer and self-taught geneticist, to seek exome sequencing. He knew that strange combinations of traits could mean a mutation.
Sequencing Vincent�s exome � the protein-encoding part of the genome � could reveal if a new mutation had arisen in him, rather than having been inherited from his parents. And that�s what happened. Vincent has his own dominant mutation in a gene called RPS23. He isn�t, however, defined by any disease. He�s a striking, active, and happy young teen who loves watching and listening to birds as he rides his mountain bike to school through a nature reserve.
His son Vincent�s unusual features � long, thick eyelashes; low-set ears; extra teeth; autistic behaviors; brittle hair; flat back of the head; hearing loss; developmental delay � had led Marc, an engineer and self-taught geneticist, to seek exome sequencing. He knew that strange combinations of traits could mean a mutation.
Sequencing Vincent�s exome � the protein-encoding part of the genome � could reveal if a new mutation had arisen in him, rather than having been inherited from his parents. And that�s what happened. Vincent has his own dominant mutation in a gene called RPS23. He isn�t, however, defined by any disease. He�s a striking, active, and happy young teen who loves watching and listening to birds as he rides his mountain bike to school through a nature reserve.
November 7, 2017
Two New Ways to Treat A Deadly Disease: Spinal Muscular Atrophy
I don�t think I�ll ever tire of covering new ways to treat genetic diseases that I�d always thought hopeless. Teamed with expanded newborn screening, the brave new treatments may even be able to prevent symptoms.
Recently reports in the medical journals of success seem to be accelerating, despite the long regulatory
Recently reports in the medical journals of success seem to be accelerating, despite the long regulatory
October 31, 2017
Will Genetics Ever Be Able to Predict the Next Mass Murderer?
Investigating a mass murder initially looks for obvious triggers in a criminal�s life, then more subtle signs, then psychiatric explanations or a brain tumor. But can errant genes help push someone to bomb marathon runners, gun down elementary school children, set a nightclub afire or rain bullets down on concert-goers?
We still don�t know what drove Stephen Paddock to meticulously plan and carry out the Las Vegas massacre on October 1. He took anti-anxiety medicine and his father was a bank robber. But robbing banks isn�t an inherited trait and millions of people take anti-anxiety medication. But could a hint of what was to come have been found in his genes?
We still don�t know what drove Stephen Paddock to meticulously plan and carry out the Las Vegas massacre on October 1. He took anti-anxiety medicine and his father was a bank robber. But robbing banks isn�t an inherited trait and millions of people take anti-anxiety medication. But could a hint of what was to come have been found in his genes?
October 15, 2017
A 31-Gene Test to Predict Alzheimer�s
When the direct-to-consumer genetic testing company 23andMe received FDA approval back in April to market a test for the e4 variant of the gene APOE, which is associated with elevated risk of developing late-onset Alzheimer�s disease, it gave people a possible peek into their futures.
About 15 percent of the population has one or two copies of the high-risk gene variant. For a long time the risk of developing Alzheimer�s for e4 double-dose individuals was 12 to 15 fold, but only 3 fold for those with one copy. Those figures have declined with re-analysis of the data.
A new 31-gene test can identify individuals at higher risk for the disease, including many who test okay for APOE e4. (Which stands for "apolipoprotein E epsilon 4 allele.")
A MORE POWERFUL TEST
About 15 percent of the population has one or two copies of the high-risk gene variant. For a long time the risk of developing Alzheimer�s for e4 double-dose individuals was 12 to 15 fold, but only 3 fold for those with one copy. Those figures have declined with re-analysis of the data.
A new 31-gene test can identify individuals at higher risk for the disease, including many who test okay for APOE e4. (Which stands for "apolipoprotein E epsilon 4 allele.")
A MORE POWERFUL TEST
October 13, 2017
As Blindness Gene Therapy Nears the FDA Finish Line, A Shout-Out to Activist Families
On a spectacular September Sunday in 2008, 8-year-old Corey Haas, using his cane and holding his mother�s hand, stepped tentatively forward on the pathway leading into the Philadelphia zoo. Hearing kids yelling about the giant balloon hanging above the zoo, he looked up � and screamed. It was the first time he�d seen the sun. Corey was headed toward certain blindness when he�d had gene therapy at Children�s Hospital of Philadelphia, just days earlier.
So begins the talk I�ve given many times since publication of my book, "The Forever Fix: Gene Therapy and the Boy Who Saved It.
Last Thursday, I was glued to my laptop, watching and listening to physicians, researchers, family, and patients present their cases for FDA approval of
Luxturna (voretigene neparvovec), the gene therapy that Corey, now a high school senior, received. He and dozens of others participating in several clinical trials can now see, thanks to the gene therapy for RPE65-mediated inherited retinal dystrophy. The treatment introduces functioning genes into the thin layer of pigmented cells that hugs the rods and cones � one time.
So begins the talk I�ve given many times since publication of my book, "The Forever Fix: Gene Therapy and the Boy Who Saved It.
Last Thursday, I was glued to my laptop, watching and listening to physicians, researchers, family, and patients present their cases for FDA approval of
Luxturna (voretigene neparvovec), the gene therapy that Corey, now a high school senior, received. He and dozens of others participating in several clinical trials can now see, thanks to the gene therapy for RPE65-mediated inherited retinal dystrophy. The treatment introduces functioning genes into the thin layer of pigmented cells that hugs the rods and cones � one time.
October 9, 2017
Brain Cancer in Kids: Tailoring Treatment Based on Mutations
I�ll admit it, I was sucked in.
"Sharon was given a few months to live if her cancer wasn�t treated," somberly intones the voiceover. Then the non-descript older woman sitting tall on a plain chair tells her story � she had non-small cell lung cancer, but, thanks to Keytruda, she�s alive a year later. The camera pans to a young relative off to the side, her eyes brimming.
When a new story extolling Keytruda appeared, starring Donna, I began to fret that something dire had befallen Sharon. It was then that I noticed, at the bottom of Donna�s story, the words "Donna is a real patient."
Was Sharon an avatar? I went back to her ad and noticed, for the first time, the scroll at the bottom of the screen: "Actor portrayal of a real patient from the clinical trial."
Oops.
"Sharon was given a few months to live if her cancer wasn�t treated," somberly intones the voiceover. Then the non-descript older woman sitting tall on a plain chair tells her story � she had non-small cell lung cancer, but, thanks to Keytruda, she�s alive a year later. The camera pans to a young relative off to the side, her eyes brimming.
When a new story extolling Keytruda appeared, starring Donna, I began to fret that something dire had befallen Sharon. It was then that I noticed, at the bottom of Donna�s story, the words "Donna is a real patient."
Was Sharon an avatar? I went back to her ad and noticed, for the first time, the scroll at the bottom of the screen: "Actor portrayal of a real patient from the clinical trial."
Oops.
September 30, 2017
Poliovirus To Treat Brain Cancer: A Curious Chronology
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.
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.
September 25, 2017
White Supremacy: The Dark Side of Eugenics
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.
Upchuck Factor: Alcoholism Targeted With Novel Gene Therapy
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.
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.
September 19, 2017
Gene Therapy and September Scenes
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.
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.
