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Various Down’s syndrome news stories

Posted in Diagnostic testing, Legal issues, Scientific research, Screening by Matt at WelcometoIllinois on February 4, 2009

I’m pretty busy at the moment so I’m just going to link to some recent items of interest for the time being:

  • Specs4Us produces glasses frames especially designed for children with Down’s syndrome.
  • The court case against four Google executives for allowing a video of a boy with Down’s syndrome being bullied to be posted on its Italian Google Video site has been delayed until later in the month. I;ve previously posted my thoughts on the matter here.

This report from eWeek nicely explains the issues at the heart of the case:

“Under Italian law, Internet service providers are not responsible for third-party content, but they must remove objectionable material if complaints are received. Content providers such as Google, however, are responsible for all posted content.

‘Google is arguing that it is an Internet service provider and the Italians are arguing Google is a content provider,’ [International Association of Privacy Professionals’ executive director Trevor] Hughes said.”

  • Ante-natal screening test supplier Sequenom has revised details of tests for its new non-invasive screening technology.

It previously stated it had achieved 100% accuracy on positive results and 99.9% on negative results. It now claims 96.6% on positive results and 100% on negative results. Yahoo Finance has the details.

Non-invasive Down’s syndrome tests make progress

Posted in Diagnostic testing, Scientific research, Screening by Matt at WelcometoIllinois on January 29, 2009

Genetic analysis company Sequenom has announced that it is making progress towards commercialising its non-invasive test for Down’s syndrome and other chromosomal abnormalities.

Based on an expanded sample of 858 tests “the Sequenom SEQureDx RNA-based technology demonstrated a 100% positive predictive value (PPV) and a 99.9% negative predictive value (NPV).”

As The Street notes, that last figure indicates that the company is no longer able to repeat its
previous claim to no false positives.

“Until today, Sequenom’s test had a 100% detection rate for Down syndrome and a 0% false positive rate when used in just under 400 pregnant women — a perfect record. While Wednesday’s disclosure of one false positive test in more than 858 total samples mars that flawless performance, Sequenom CEO Harry Stylli says an overall false positive rate of one-tenth of 1% is significantly better than current prenatal screening methods for Down syndrome, which can have a false positive rate of around 5%.”

UPDATE – It turns out the test results were wrong – UPDATE

According to The Street, the test works like this:

“The Sequenom test relies on new technology that can detect minute amounts of fetal RNA in a mother’s bloodstream. Using a small sample of blood taken from the mother, Sequenom isolates fetal RNA [ribonucleic acid] and determines whether there are two copies of chromosome 21 (a healthy baby) or an extra copy of the chromosome, which would indicate Down syndrome.”

Sequenom is coming to make its test available in the US in June, although as Xconomy reports “The medical audience will demand evidence published in peer-reviewed journals, and loads of it, before they give their full stamp of approval.”

Detailed results should be published in peer-reviewed journal in mid-2009, according to the company. Recommendation from American College of Obstetricians and Gynecologists will likely not come until 2010 or 2011, at the earliest.

Sequenom is not the only company developing new non-invasive testing techniques. I previously wrote about similar testing technology under development at Stanford University being licensed to a company called Fluidigm.

A company called Artemis Health has also acquired a license from Stanford University to develop cell-free fetal DNA prenatal diagnostic tests.

Meanwhile a company called Lenetix announced that it is making progress with maternal serum test developed at the University of Vermont that make use of methylation-sensitive amplification (MSA) of fetal nucleic acid markers.

Understanding of Down’s syndrome may aid breast cancer therapy

Posted in Scientific research, Therapeutic treatments by Matt at WelcometoIllinois on January 9, 2009

Here’s a pretty interesting theory on how the understanding of Down’s syndrome may help in the development of therapy for breast cancer sufferers.

Apparently breast cancer is rare amongst women with Down’s syndrome, possibly because of the extra copy of chromosome 21, which is “where the gene that codes for the antiangiogenic protein Endostatin is located”.

The theory is that treating people with Endostatin “a Down syndrome level” could be a therapy for early stage breast cancer that indefinitely prolongs remission and makes chemotherapy or hormone therapy unnecessary.

From the perspective of attitudes towards Down’s syndrome the interesting thing about this is that it is only possible to put forward this theory now that women with Down’s syndrome are living to an age when it is most common (50 to 69 according to NetDoctor).

A study conducted in 2000 indicated that while people with Down’s syndrome have an increased risk of leukemia, they have a lower incidence of many other forms of cancer, including breast cancer.

Meanwhile a year ago a study at Johns Hopkins University School of Medicine indicated that a gene called Ets2 that sits on the 21st chromosome may, alongside endostatin, be key.

“If there were no such thing as Down syndrome, we probably wouldn’t have found this because it wouldn’t make a lot of sense to take these oncogenes that we thought were genes that cause cancer and try to express them at high levels to try to prevent cancer. But that’s what happens,” said researcher Roger Reeves. “People with Down syndrome have now given us all the possibility of lowering the incidence of cancer in everybody.”

Test for birth defects may cause birth defects

Posted in Diagnostic testing, Scientific research, Surveys by Matt at WelcometoIllinois on January 5, 2009

Damned if you do…

I read this report back before Christmas on the risks related to chorionic villus sampling (CVS), a common prenatal diagnostic test for Down’s syndrome, but I didn’t really take it in.

A study by Dr. Lewis B. Holmes of Massachusetts General Hospital for Children has reviewed past research on the possible link between CVS and birth defects and indicated that CVS may increase the risk of that the baby will be born with a birthmark, or “infantile hemangioma” or even limb defects.

According to this report from Reuters:

“In one study, Holmes reports, researchers found “cavernous or strawberry hemangiomas” in 12 of 95 (12.6 percent) CVS-exposed infants compared with 3 of 87 (3.4 percent) infants who had been exposed to amniocentesis, which is typically performed later in pregnancy.

In another study, hemangiomas were seen in 21.1 percent in 578 CVS-exposed infants versus 7.4 percent in 445 amniocentesis-exposed infants. Some babies in the CVS group, but none in the amniocentesis group, had multiple hemangiomas.

Holmes also looked at the evidence for an association between CVS and birth defects involving the limbs, especially the fingers, and found some “clear” correlations. The evidence suggests that these risks are greater when CVS is performed earlier in pregnancy, such as at 8 to 9 weeks gestation.”

The Editor-in-Chief of the Journal of Craniofacial Surgery points out that “CVS is generally done for prenatal detection of serious genetic diseases like Down’s syndrome in pregnancies at high risk” and that “the benefits of knowing the test results could outweigh the possible risk of hemangiomas or other abnormalities”.

Which is probably true, but the risk of birth defects should also be factored into any cost/benefit analysis of diagnostic testing. I certainly don’t remember it being mentioned when we were preparing for our CVS test.

Down’s syndrome frequency doubles in Japan

Posted in Scientific research, Statistics, Surveys by Matt at WelcometoIllinois on December 23, 2008

In the past 25 years the frequency of babies born with Down’s syndrome has doubled, according to this report in The Manichi Daily News.

It could be a translation issue, but the use of the word ‘frequency’ suggests this isn’t just a matter of the number of cases of Down’s syndrome increasing in line with (or below the rate of) increases in birth rates in general.

The Manichi news report mentions this statistic in relation to a planned epidemiologic study to probe the connection between the environmental use of chemical substances and childhood illness.

It does not state whether the research will investigate the impact of the environment on the cause of Down’s syndrome, which would be interesting, or just look at the impact of the environment on children with Down’s syndrome.

The reports states:

“The ministry’s study will investigate the amount of chemical substances that enter children’s bodies and investigate the relationship with abnormalities in their immune systems, development disorders and other conditions. Assistance will be sought from about 60,000 pregnant women across the country from fiscal 2010. In addition to collecting umbilical blood, researchers will conduct regular examinations of children from around the time of their birth until they reach the age of 12 to determine their health status. The results of the survey are expected to be compiled in about 2025.”

A quick Q&A on stem cell research

Posted in Scientific research, Therapeutic treatments by Matt at WelcometoIllinois on December 16, 2008

Stem cell research is a pretty controversial issue for some people. It’s not something I’ve spent too much time thinking about but as I have previously reported, it could potentially lead to improved understanding of, and treatment for, the effects of Down’s syndrome.

It is in that context that I think this Q&A in the New York Times is worth a read. It is an interview with Renee A. Reijo Pera, director of Stanford’s Center for Human Embryonic Stem Cell Research and Education.

While it is focused on the use of stem cells for fertility treatment it also helped me to understand some of the basic issues related to stem cell research.

Patenting non-invasive tests for Down’s syndrome

Posted in Business, Diagnostic testing, Scientific research, Screening by Matt at WelcometoIllinois on December 4, 2008

I have previously written about two new non-invasive diagnostic tests for Down’s syndrome. One created by a company called Sequenom after research at the Chinese University in Hong Kong, and the other under development at Stanford University.

GenomeWeb is reporting that both teams have claimed patents related to their research (the article is available for subscribers, but a cached copy of of the report is available here), and that a company called Fluidigm has secured co-exclusive licenses to the Stanford researchers’ inventions.

If I know anything about intellectual property and business (and I know a little bit) then it would seem likely that these two groups will be at loggerheads over the patents for some time to come.

Given the apparent accuracy of their research I hope business interests do not slow down the development of diagnostic testing techniques that replace less accurate screening procedures. Given it is estimated that the Down syndrome testing market is worth at least $1bn it seems inevitable that they will, however.

Ozone as treatment for immunological problems

Posted in Scientific research, Therapeutic treatments by Matt at WelcometoIllinois on December 3, 2008

We found our this morning that our little boy has a chest infection and is being put on antibiotics again, which is something we would like to keep to a minimum.

He is pretty strong and healthy but does seem to suffer from colds more than his brother, so it’s not a major worry but is a reminder that Down’s syndrome often comes with immunological problems.

Which brings me to this story about research underway in Cuba to trial using ozone as a therapy for blood, nutrition and hormone problems, as well as issue with the immune system.

According to the report the study will be run at the Sancti Spiritus’s pediatric hospital with the cooperation of Havana’s Ozone Investigation Center and the first phase will see researchers try to determine the blood biochemical disorders of 30 children with Down’s syndrome which makes them vulnerable to different diseases.

This will lead to clinical trial of ozone as an anti-oxidative agent to improve the immune system.

The use of DNA chips in diagnostic testing

Posted in Diagnostic testing, Scientific research by Matt at WelcometoIllinois on December 1, 2008

I previously wrote about the use of “‘microarrays’ or gene chips in the genetic testing process and a new DNA test called array comparative genomic hybridization (aCGH). MIT Technology Review has an overview of the technology.

The DNA chip used in the study performs a process known as array comparative genomic hybridization (aCGH), which involves looking for an abnormal number of copies of particular segments of DNA. Normally, humans have two copies of each segment. Having extra or missing copies can result in serious medical problems. Each DNA chip contains hundreds of single-stranded DNA segments, each embedded in a piece of glass at a precise location. The researchers then add single-stranded, fetal DNA segments, usually taken from amniotic fluid. These strands are labeled red. Single-stranded DNA reference segments, which act as a control group and are labeled green, are also added to the chip. Once the fetal and control strands are bound with the embedded DNA, the arrangement of colors on the chip is imaged and analyzed by a computer.

“Basically we measured the color signal intensity,” said [Sau Wai Cheung, director of Baylor College of Medicine’s Cytogenetics Laboratory]. If the fetus has an extra copy of a particular segment of DNA, then the spot on the chip that corresponds to that DNA segment will appear more red than green. If the fetus is missing a DNA segment, the corresponding spot on the chip will appear more green than red. And if the fetus has the correct number of copies of the DNA segment, then the spot should appear yellow.

To put this in some context:

“The process normally used for prenatal diagnosis is karyotyping, which looks at the overall size and shape of chromosomes to identify problems. [Cheung] says the new research shows that DNA chips can reliably detect far smaller chromosomal abnormalities than karyotyping allows. And while these abnormalities may be small in size, they can have a big impact. “A lot of the diseases that we tested for [in this study] cause mental delays and problems with physical development,” said Cheung. Angelman syndrome, for example, can result in significant developmental problems and seizures.”

The study at Baylor included 300 cases and identified seven cases where the aCGH results provided new information about the risk of disease, “including two cases that would otherwise have been missed”. On the downside still requires an invasive testing procedure and has not been widely studied at this stage.

In fact, I previously mentioned the technique in the context of a warning from Leslie G. Biesecker of the federal government’s National Human Genome Research Institute, that the tests do not provide enough information to know whether genetic abnormalities will actual cause a disorder, or how severe the effects might be.

The MIT Technology Review story raises the same issue, as Diana Bianchi, professor of pediatrics, obstetrics, and gynecology at Tufts University School of Medicine and the editor in chief of Prenatal Diagnostics (which published details of the Baylor study): “The downside of aCGH is you pick up these copy-number variants that may or may not have clinical significance, and in the worst case [the impact] may be unknown.”

The reports adds: “Knowing that an unborn child has genetic abnormalities but not knowing how those might affect the child’s development could leave many parents scared and confused, Bianchi says.”

Of course that is the exact same issue that impact parents receiving screening and diagnostic test results today, but no one seems to bother about that.

In utero treatment for Down’s syndrome?

Posted in Scientific research, Screening, Therapeutic treatments by Matt at WelcometoIllinois on November 26, 2008

New Scientist is among a number of news sources reporting that it may one day be possible to treat the symptoms of Down’s syndrome before a child in born via a protein injection.

The report indicates that injecting proteins could make up for malfunctions in glial cells and protect neurons that would otherwise be impacted by Down’s syndrome. According to the report:

“Catherine Spong and colleagues at the National Institutes of Health in Bethesda, Maryland, injected NAP and SAL into mice pregnant with trisomic pups in the middle of their pregnancy. When the pups were born, they reached developmental milestones such as grasping a rod, righting themselves and responding to tactile stimulation at the same time as normal mice.”

There are no guarantees that the treatment would have the same effect on humans, of course, but it does raise an interesting scenario where screening tests can also be used to enable treatment, rather than termination.

See also NHS Behind the Headlines’ take on this story: “It is unclear whether the improvements seen in mice would be seen in humans, and whether such improvements would significantly alter the impact of Down’s syndrome on the individual.”