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Genetic Linkage

A Proposed DNA Data Protection Act? The Cat’s Out of the Bag

A team of biologists, policy analysts, and legal experts from the University of Queensland call for a new Genetic Data Protection Act in an article just published in Genetics in Medicine.

A new law is needed now, the researchers argue, because of the increasing difficulty of keeping the threads of DNA use separate. “What happens to our genetic data in one realm, such as forensics, is highly likely to affect how society trusts the use of genetic data in medicine. The speed of these developments has surprised many and demands a policy response to protect trust in medical genetics,” they write.

A data protection act is a great idea, but isn’t it a little late? The collision between genetic privacy and the consumer testing data dump that forensics is tapping into is already here. And it may detonate when the millions of DNA kits sitting under Christmas trees right now are translated into information. Read More 

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Cystic Fibrosis Among Asians: Why Ethnicity-Based Genetic Testing is Obsolete

Pseudomonas aeruginosa, a bacterium that inhabits the lungs of many people who have cystic fibrosis, but is otherwise rare.
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 
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The Man Who Ate 25 Eggs a Day

Cholesterol isn't the enemy -- triglycerides are.
Each morning at the retirement community, the healthy 88-year-old man received a delivery of 25 soft-boiled eggs, which he would consume during his day. This had been his way for many years. He’d had one experience of chest pain that might have been angina, but aside from that, he had a healthy cardiovascular system. He recognized that his only problem was psychological: “Eating these eggs ruins my life, but I can’t help it.”

I think of the Eggman, a brief case report from 1991 in the New England Journal of Medicine, whenever "news" of cholesterol’s unsuitability as a one-size-fits-all biomarker resurfaces, as it does every few years and did again a few weeks agoRead More 
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DNA and Dating: Buyer Beware

Is DNA dating destiny?
Last week’s post dealth with three very serious applications of DNA testing. But not all DNA testing is to detect health-threatening conditions.

“Born to Run? Little Ones Get Test for Sports Gene,” ran the headline on the front page of the New York Times, above an arresting image of a preschooler having his mouth swabbed for DNA. It’s from 2008, but remains a classic: I still assign it.

The sports gene company is apparently still around and still testing for variants in just one gene: ACTN3. Two copies of the R577X variant indicate inborn skill at endurance events, and no copies suggest a child stick to sprints. The lucky heterozygotes might excel at both! Never mind that a child has some 20,000 or so other genes affecting physiology.

DISSECTING A DNA DATING WEBSITE
The most damage a sports gene test can do is to keep a child from doing something she loves because of a DNA-obsessed parent. A more questionable application of DNA testing is as part of “relationship science,” something I learned about a few weeks ago when a reporter from healthline.com asked me about it. Read More 
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Genetic Testing For All: Is It Eugenics?

(NHGRI)
In recent weeks, there’s been talk of three types of genetic testing transitioning from targeted populations to the general public: carrier screens for recessive diseases, tests for BRCA cancers, and non-invasive prenatal testing (NIPT) to spot extra chromosomes in fetuses from DNA in the maternal bloodstream.

Are these efforts the leading edge of a new eugenics movement? It might appear that way, but I think not.

When I began providing genetic counseling 30 years ago at CareNet, a large ob/gyn practice in Schenectady, NY,  Read More 
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New Guidelines on Testing Kids’ DNA – the Cliff’s Notes Version

Should kids have genetic tests? It depends. (NHGRI)
Exomes are big news. Sequencing of the protein-encoding part of the genome is increasingly solving medical mysteries in children. It began with Nicholas Volker and his recovery from a devastating gastrointestinal disease with a stem cell transplant once his exome sequence revealed his problem. And recent Medscape assignments reveal the trend: 7 of 12 kids’ exomes leading to diagnosis at
Duke University
from May 10, 2012; whole genomes of 5 infants from the neonatal intensive care unit at Children’s Mercy Hospital and Clinics in Kansas City, Missouri from October 3, in under 2 days each, focusing on 600 single-gene diseases; and 300 patients at the Whole Genome Laboratory at the Baylor College of Medicine, with 300 more waiting -- 85% of them kids, from November 9, 2012. (You have to sign in to Medscape; it’s free.)

But wait.

Before we all run out to get our exomes and/or genomes sequenced, Read More 
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Male DNA in Female Brains Revisited

Fetal cells remain in moms -- that isn't news. But the discovery of fetal DNA in women's brains is. (credit: Jay Shendure lab)
“Some women actually have men on the brain” beckoned the headline from the LA Times on September 27, echoing an article in PLoS One describing the discovery of male fetal DNA in the brains of pregnant women. It was “an astonishing finding,” according to the newspaper, necessitating “a new paradigm of the biological self” according to lead author J. Lee Nelson of the Fred Hutchinson Cancer Research Center and the University of Washington.

I suspect Dr. Nelson was quoted out of context, for the idea of two genetically distinct populations of cells, or their DNA, residing in one individual isn’t new. It’s called microchimerism. Read More 
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DNA Science -- My New Blog at Public Library of Science (PLoS)

I have a new blog at Public Library of Science (PLoS), DNA Science. Each Thursday I'll explore stories from real people experiencing opportunities and challenges posed by biotechnology, including genetic testing, gene therapy, exome sequencing, stem cells, and more.

I like to find the stories that no one else tackles, connect topics in unusual ways, dip into bioethics, and wherever possible, bring in the historical perspective that shows that "overnight breakthroughs" are almost always anything but. And the PLoS tag is opening doors -- I spoke with Dr. Francis Collins yesterday!

The first blog is "Human Embryonic Stem Cells Finally Reach Clinical Trials: Maurie's Story."

Join me on this new adventure! Read More 
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Anticipation

Jordan and Hailey Kohl. Spinocerebellar ataxia type 2 affects several members of their family, including Jordan.
“Anticipation .. is keepin’ me waitin’,” sings Carly Simon in her song made famous in a ketchup commercial. But “anticipation” in the genetic sense is just the opposite of Carly’s croon – it means a disease that begins earlier with each generation.

Doctors once blamed patients for anticipation, as if people with sick older relatives could worry themselves into suffering similarly. Then, in 1991, discovery of a new type of mutation explained the curious worsening of fragile X syndrome: an expanding triplet repeat.  Read More 
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