Apr 30, 2009

Autismo: individuate le varianti genetiche.

Tre studi americani pubblicati su Nature on-line e su Annals of Human Genetics, hanno identificato le cause genetiche che sarebbero associate all’autismo. Le mutazioni paiono avvenire nel cromosoma 5 localizzato tra i geni responsabili delle proteine di adesione cellulare, la caderina 9 (CDH9) e la caderina 10 (CDH10). In tutti e tre gli studi sono stati confrontati i dati sui cromosomi tra individui sani ed individui autistici, e così è stato possibile individuare la mutazione in aree già note per lo sviluppo anomalo del cervello nei bambini autistici. Siamo ancora lontani da una cura, ma almeno ora sappiamo perché si sviluppa questa malattia.

Apr 29, 2009

Diagnosi pre-concepimento

Lo scorso febbraio per via di una conferenza stampa, è stata data la notizia di una nuova procedura che consente di diagnosticare tutti i tipi di malattie genetiche e cromosomiche a trasmissione materna senza toccare gli embrioni. La tecnica, chiamata “diagnosi pre-concepimento” e pubblicata sul numero di gennaio della rivista scientifica Prenatal Diagnosis, è stata messa a punto da un team italiano coordinato da Francesco Fiorentino, biologo molecolare e direttore del Laboratorio Genoma di Roma.

In Italia la legge 40 sulla fecondazione assistita è molto controversa e, fino ad oggi, ha vietato la diagnosi pre-impianto. La problematica etica riguarda la possibilità di selezionare gli embrioni con l’eliminazione di quelli malati. La diagnosi genetica pre-concepimento viene eseguita sull’ovocita e non sull’embrione. In particolare, la tecnica permette di studiare i gameti femminili prima della loro fertilizzazione in vitro con lo scopo di escludere quegli oociti il cui DNA risulta alterato alla diagnosi, ed evitare quindi a priori la possibilità di produrre embrioni con anomalie genetiche. In quest’ottica la diagnosi pre-concepimento consente di superare gli ostacoli etici. “Con questo metodo siamo riusciti ad ottenere una prima gravidanza in una donna laziale portatrice per la sindrome Charcot Marie Tooth. Reduce da gravidanze andate male e da viaggi all’estero, la donna è oggi al suo terzo mese e i dati ottenuto dalla villocentesi hanno confermato che il feto è sano”, ha dichiarato Francesco Fiorentino.

La procedura, che è stata finora effettuata in via sperimentale, è stata validata a livello internazionale ed è ora in fase di proposta per l’attuazione in ambito sanitario. Le patologie genetiche per le quali la diagnosi pre-impianto potrebbe trovare una valida applicazione comprendono quelle a trasmissione autosomica recessiva, come ad esempio la fibrosi cistica, la talassemia e la SMA, o quelle di origine materna, quali la distrofia muscolare di Duchenne-Becker e l’X-Fragile.

Secondo Francesco Fiorentino questa nuova tecnica ha le potenzialità di dare, in un futuro prossimo, una reale possibilità alle coppie italiane portatrici di queste patologie di avere figli sani, senza dover ricorrere a costosi viaggi all’estero per ottenere trattamenti vietati in Italia.

Intervista a Francesco Fiorentino su RadioRadicale

Apr 28, 2009

coriell personalized medicine centre (PMC)

Coriell is a non-profit medical research institution providing the same SNP testing technology, but as a responsible, accountable medical research collaboration to determine its clinical application. Coriell provides its SNP tests at no cost to participants, and they only offer testing in a medical setting, not directly to consumers through the mail. Further, Coriell fully claims that their genomic tests are to be used by physicians to produce actionable medical advice (NOT as “information only”). Finally, unlike other SNP test competitors, Coriell has always operated with CLIA certification, has always operated under the supervision of an Informed Cohort Oversight Board (ICOB), and has obtained a Certificate of Confidentially which authorizes Coriell “to withhold the names and other identifying characteristics of individuals who participate protecting them against the compelled disclosure of any personally identifiable information in any Federal, State, or local civil, criminal, administrative, legislative or other proceedings.” No other similar service offers this protection.

Apr 27, 2009

deCODEme

deCODEme has blundered into the same “medicine that’s not medicine” fraudulent territory as Navigenics, but they do not make as good of a negative example as Navigenics does because deCODEme is not the DTC genomics leader. If deCODEme survives, it will follow the examples of others, so I propose no special effort to make them a negative example. It’s more important to focus the already diluted messages of the personalized medicine community than it is to be “fair.” However, I propose to hold deCODEme to the same standards as Navigenics if the challenge arises.

Apr 26, 2009

navigenics

Navigenics clearly states that it accepts no responsibility in all contexts —including medical advice. Thus, no responsible physician can promote Navigenics. Yet, Navigenics continues to promote themselves as “partnering with physicians” to provide their “Health Compass” service to “ensure state-of-the-art medical advice” and to “help you make informed, personal health decisions.” Left unchallenged, these statements will continue until they are assumed true. Thus, no responsible physician may practice non-participation. I have yet to see one single actionable medical claim about Navigenics—a fact explicitly expresses in their Terms and Conditions  and never contradicted by Navigenics‘ medical director, Michael Nierenberg. Thus, in a “partnership” between Navigenics and a physician, Navigenics gets all the money and the credit, the patient gets to pay more for less care, and the physician gets all the liability and the work of producing the medical advice. This is your roll in the “medical revolution” pledged to you by your bleached-out BIZDEV! “friends.” Participate, and you’re either a sucker or a sellout —not a responsible physician.Worst of all, Navigenics thinks that they can sell “medicine that’s not medicine” through clever marketing and physician partnerships, enriching Navigenics now while they dodge the liability of medical responsibility later. For the same reasons that credit-swapping “insurance that’s not insurance” should have never been tolerated, this kind of “is isn’t” sophistry sets an industry precedent by which one may sell  a promise now without accepting any of the expected future value of liability already built into the system to prevent abuse. Like insurance, since preventive medical advice is an abstract promise, once the precedent of accepting no liability has been set and successfully tested, non-liable preventive medical advice can be infinitely created and sold with no physical limits… until the system breaks. Understandably, some people will be less likely to trust non-liable advice. The solution is to package non-liable advice with liable, trusted medical institutions until the public is so confused that it is unable to sort reality from fiction. Finally, once the business model of selling free and infinite non-liable medical assets by packaging them with and laundering them through trusted medical advice has been sufficiently demonstrated to the investment community, responsible ventures will not be competitive for investment capital.Thus begins the great genomic industry sellout race to zero trust. At the end, disposable start-up companies like Navigenics cash out and collapse (or just collapse), and surviving trusted institutions of medicine get stuck with the loss.Navigenics is an unprofitable venture-funded web start up created by Silicon Valley investors to test the limits of the personalized medicine market. I propose that the physician community compose the results of that test.

Apr 25, 2009

23andMe

The pragmatic, political reality is that 23andMe is the public pet project of a billionaire’s wife. It’s not going to die, it’s not going to be thwarted by institutional disapproval, and it has to go somewhere.Thus, I propose to let 23andMe have their novelty consumer web service “data democracy,” but firmly block any implied medical application until the accountability and clinical application demands of the medical community are met. It’s wholly appropriate to have no medical opinion about an inactionable novelty consumer product so long as that product is not marketed otherwise.Maintain state control: you want to know what 23andMe is going to do and why. Do this by blocking where you don’t want them and making it easy for them to be somewhere that’s not valuable to you (novelty consumer web services). Don’t unilaterally block them with weak ideas like “your feelings as a doctor” because that offers 23andMe no acceptable response. Again, 23andMe has to go somewhere, so offering no acceptable response forces 23andMe to behave unpredictably (and in your offered context, unacceptably) without achieving any useful objective. Worse, sloppy, disorganized attacks brand you as uncooperative partisan to be mitigated —not a as leader. That will be a problem for you in Silicon Valley as the medical application of informatics and the internet continues to advance. Maybe impulsive attacks once helped galvanize the medical community when 23andMe was first announced —and maybe that was necessary at the time— but these impulsive attacks are now counter-productive and should be discouraged. Further, unlike Navigenics, 23andMe is far more transparent regarding the scientific data justifying its reports and openly engages the scientific community. This transparency should be rewarded, not punished, and using this transparency to justify impulsive attacks will set a president that transparency is an untenable liability in preventative medicine. This helps nobody. Again, while scientific transparency may not be appropriate to include in medical advice, it is absolutely appropriate to include in novelty consumer web services. Thus, for the case I make above, while both Navigenics and 23andMe are guilty of irresponsible medicine by marketing, I propose that the medical community permits 23andMe to exist as a novelty consumer product only with no medical insinuations until 23andMe chooses to practice medicine responsibly.

Apr 24, 2009

the hype of genetic testing is waning?

SNP chip testing is in a hype cycle, and both the peak and the trough are irrational and destructive. The Times #1 invention was probably the apex of this period, and we already know that the industry is in for hard times regarding Navigenics, deCODE, and continued economic difficulties.

As for foxing, the cycle is predictable. Here’s how it will go: 
Something new and futuristic! 
Wow, DNA and mutations, just like in comic books!
23andMe is the most important invention in the world
“Have we gone too far?"
A prosaic, hard-hitting piece about serious doubts
Genetic testing is a bunch of bollocks and everybody involved is a greedy hack
We’re wasting money on astrology and astrologists
Back to basics! some very good study reports application of genomics with obviously positive results
Genomic medicine is another ordinary tool with it’s own applications
People trust it for what it is, and media coverage dims to mean neutral hum

We know that will happen, so our strategy is simple: Be honest, be transparent, be available, be consistent. No hype. Just responsible medical professionals reliably providing respectable medical advice and best-effort expert opinions —except from a genomic specialty perspective. The public will find you when the truth is fashionable again, and you won’t have to spend millions of dollars to win the hype game.

Apr 23, 2009

whole genome amplification and real-time PCR in forensic casework

from 7th space interactive

http://7thspace.com/headlines/306929/whole_genome_amplification_and_real_time_pcr_in_forensic_casework.html

Apr 22, 2009

Genetic Risk Prediction — Are We There Yet?

(from Peter Kraft, Ph.D., and David J. Hunter, M.B., B.S., Sc.D., M.P.H. - New England Medical Journal)

a major goal of the Human Genome Project was to facilitate the identification of inherited genetic variants that increase or decrease the risk of complex diseases. The completion of the International HapMap Project and the development of new methods for genotyping individual DNA samples at 500,000 or more loci have led to a wave of discoveries through genomewide association studies. These analyses have identified common genetic variants that are associated with the risk of more than 40 diseases and human phenotypes. Several companies have begun offering direct-to-consumer testing that uses the same single-nucleotide polymorphism chips that are used in genomewide association studies. These companies claim that such testing should be made available to consumers who are interested in their personal level of risk for the relevant diseases. Now, “risk tests” for specific diseases such as breast cancer are also being marketed to physicians and consumers. 
The availability of highly predictive and reasonably affordable tests of genetic predisposition to important diseases would have major clinical, social, and economic ramifications. But the great majority of the newly identified riskmarker alleles confer very small relative risks, ranging from 1.1 to 1.5, even though such analyses meet stringent statistical criteria (i.e., the identification of associations with disease that have very small P values and hence are unlikely to be false positives). However, even when alleles that are associated with a modest increase in risk are combined, they generally have low discriminatory and predictive ability. 
One argument in favor of using the available genetic predictors is that some information must be better than no information, and we should not let the perfect be the enemy of the good by refusing to make use of our knowledge until it is more complete. Why not begin testing for common genetic variants whose associations with susceptibility to disease have been established? The answer lies in the stability of the current risk estimates. 
The good news is that pooling the results of multiple genomewide association studies has led to increased statistical power and the discovery of many new loci linked to small increases in the risks of major diseases and phenotypes. For example, pooling efforts have led to the identification of more than 16 new loci associated with diabetes and more than 30 loci linked to Crohn’s disease. From a scientific perspective, we would like to know roughly how many risk loci remain to be discovered. From a clinical and policy perspective, we would like to know the extent to which the available associations are useful for measuring risk, both in absolute terms and relative to the expanded set of associations that are likely to be discovered in the next few years. 
Although we know of many more risk loci than we did 2 years ago, there are probably many more associations that are yet to be discovered for these complex diseases. Less common variants in the prevalence range of 0.5 to 5.0% also remain to be discovered. Estimates of risk based on established locus associations are therefore likely to change substantially in the next few years. But this is only one of the factors determining whether knowledge of genetic risk is beneficial. The clinical value of a genetic test also depends on its sensitivity, specificity, and positive and negative predictive values; the costs and benefits of interventions; and the availability of data linking specific variants to improved clinical outcomes. In particular, although we will be better able to distinguish subtle differences in risk as we discover more risk loci, most people will still be at or near the median level of risk. As a result, for less-common diseases (with a prevalence of 1% or less), the positive predictive value of a genetic test will almost always be low. 

We are still too early in the cycle of discovery for most tests that are based on newly discovered associations to provide stable estimates of genetic risk for many diseases. Although the major findings are highly unlikely to be false positives, the identified variants do not contribute more than a small fraction of the inherited predisposition. Once risk estimates are more stable, the usefulness of genetic screening will need to be considered for each disease, and recommendations about potential interventions will need to be made for persons whose predicted risk exceeds some threshold. Appropriate guidelines are urgently needed to help physicians advise patients who are considering this form of genetic testing as to how to interpret, and when to act on, the results as they become more stable.

(sent by M Cesco Gaspere)

Apr 21, 2009

personal gene tests show limited use

by Elizabeth Lopatto and John Lauerman April 2009 (Bloomberg)

Companies that sell DNA testing to pinpoint individual risks for common diseases provide little real information, says one of four commentaries featured in the New England Journal of Medicine. David Goldstein, a Duke University researcher, wrote that most common
disorders, including cancer and diabetes, involve hundreds of genes, and that many mutations may have the capacity to raise a person’s risk. That suggests the testing offered by companies now, which focuses on the few variants that have already been identified, isn’t likely to spot people at highest risk, he said. “In pointing at everything, genetics would point at nothing,” Goldstein wrote yesterday in the journal.

DeCode Genetics Inc., based in Reykjavik, Navigenics Inc., of Foster City, California, and 23andme Inc., of Mountain View, California, are among companies that test the DNA of individuals to pinpoint variants that may identify disease risk. The journal commentaries are the first public forum featuring leading genetic researchers discussing the usefulness of so-called genome-wide association studies, research that scans the DNA of thousands of people to identify mutations that may be common to certain ailments. The headline on the lead commentary asks, “Are we there yet?” The answer suggested by the authors is not quite.

Human Genome Project Researchers hoped the studies, made possible by completion of the Human Genome Project in 2003, would open new windows on why ailments such as cancer
and diabetes occur, and allow doctors to offer highly personalized treatment regimes that would focus on the underlying cause. At the same time, companies such as DeCode, Navigenics and 23andme have designed tests, costing as much as $1,000 apiece, that search through the genomes of individuals for hints disease may be hiding based on findings from
the larger research. The association studies helped make it “routine to identify common, low-risk variants” present in less than 5 percent of the population that confer only “small” risks of disease, wrote John Hardy, a researcher at the Institute of Neurology at the University College London, and Andrew Singleton, of the Laboratory of Neurogenetics in Bethesda, Maryland, in one of the four commentaries.

Genome-wide association studies haven’t explained as much of the genetic components of disease as anticipated, wrote Goldstein, director of the Center for Human Genome Variation at Duke University in Durham, North Carolina. For that reason, scientists ought to spend more time looking at rare variants that could lead to new drugs or suggest the designs for personalized prevention programs, he said. Beyond the variants for Alzheimer’s disease,
glaucoma and macular degeneration, “there are probably either no more common variants to discover, or no more that are worth discovering,” Goldstein said.

Personal tests scanning the whole genome give a lot of useless information; wouldn't there be a better solution in designing tests targeted to specific clinical conditions?

Apr 20, 2009

preparing doctors for the genomic tsunami

Mark Henderson has a great piece in the Times exploring the impact of personal genomics on the practice of medicine.

The basic theme should be familiar to anyone who has been following the emergence of the personal genomics industry: doctors are currently almost completely unprepared for the onslaught of genetic information they are about to experience. Here's the situation: at present, genetic training focuses on Mendelian diseases - rare mutations in single genes, which usually have severe effects. People who inherit the Huntington's mutation, for example, will invariably develop the fatal brain disorder, while 80 per cent of women who have a mutated BRCA1 gene will contract breast cancer.


This focus is perfectly understandable. Doctors need to understand and recognise these disorders, even if they will see few cases. Until recently, too, Mendelian conditions were the only ones for which genetic roots had been properly established. A knowledge of these rare diseases, however, is not going to be much help when patients start to visit their GPs waving printouts from genome scans like the one I took.

The genome scans Henderson describes are analyses of hundreds of thousands of common genetic variants scattered throughout the genome, currently offered by companies such as 23andMe, deCODEme and Navigenics (Henderson had his own genome scan performed by deCODEme). Over the last three years around 400 of these common variants have been convincingly associated with almost 80 common diseases and complex traits - everything from eye colour to prostate cancer - but each variant typically has a very small effect on disease risk, usually increasing it by 10-70% above baseline risk. That means that the results of a modern genome scan are very different to the clear-cut diagnostic genetic tests that clinicians are most familiar with: instead of telling a patient that they will almost certainly contract a serious, rare disease, clinicians are faced with a series of fuzzy probabilities: a lifetime risk of type 2 diabetes of 27% compared to the population average of 22%, for example. 

The task of sorting clinically relevant information from statistical noise is daunting even for experts - let alone for GPs, lacking any training in modern genomics, who might have a 10 or 15 minute consultation to reassure a bewildered patient. In such cases the temptation must be strong to simply shrug their shoulders, tell the patient that the whole lot is garbage, and get back to the business of treating patients with actual diseases.


Yet to do so would be a grave mistake. Even current genome scans can yield clinically valuable data regarding the risk of some diseases, such as Alzheimer's, or the risk of adverse reactions to drugs like warfarin. But it's also crucial to note that current genome scans represent just our first feeble steps into the world of predictive health genetics: in less than five years large-scale DNA sequencing will be cheap enough for whole-genome sequencing to become routine, and during that time our understanding of the genetic basis of common diseases will continue to grow exponentially. If individual doctors - and the medical establishment as a whole - fail to adapt quickly to the approaching genomic era then patients will miss out on the substantial benefits of genomic medicine.


The only possible solution is intensive clinician education: both incorporating genomic knowledge deeply into medical degrees, and offering continuing education to practising doctors. Of course it's hard to teach about a field that is developing so rapidly, and Henderson notes that course material will need to be broad and flexible: 


Personal genomics is in its infancy, and with new discoveries emerging all the time, we cannot yet know the detail of what tomorrow's doctors will need to know. They do not need to learn about every variant that has been linked to a disease risk or drug response: that knowledge remains incomplete, and it can always be looked up. What they do require, however, is an appreciation of how genetic discoveries are likely to become integrated into medical practice, and basic skills to make the most of them. In other words, doctors won't need to memorise the fact that the T version of variant rs7903146 is associated with type 2 diabetes; but they will need to know the difference between a SNP and a CNV, or between a genome scan and a genome sequence. They will need to become familiar with the terminology and interpretation of probabilistic genetic risk estimates and with the use of available online resources.


There is genuine urgency here. Right now it is a simple fact that 23andMe explains the implications of a genome scan far more accurately than the vast majority of clinicians ever could, a fact that makes many of the lamentations of the medical establishment about the dangers of direct-to-consumer genomics (at least at the high end of the market, i.e. 23andMe and deCODEme) seem rather absurd. If clinicians want to re-establish their centrality in the era of genomic medicine they have a lot of catching up to do - and they need to do it fast.


Apr 19, 2009

pubget

Each year, scientists and doctors spend more than a quarter billion minutes searching for biomedical literature online. This is time that could better be spent exploring science and curing disease. Pubget was founded to give you that time back. Check it out at http://pubget.com/.

Apr 18, 2009

genetic tests can forecast bald facts in each man’s future

(From The Times, October 13, 2008)

One man in seven has a genetic profile that will raise dramatically his chances of going bald at a young age, according to research that could lead to new ways of predicting and preventing hair loss.

Men who inherit two particular genetic variants are seven times more likely to develop male pattern baldness by their forties than those who carry neither, a British-led team has found. The discovery, from the first study to trawl the human genome for passages of DNA linked to baldness, will allow young men to discover with much greater accuracy whether and when they are likely to lose their hair.

Some may then wish to try drugs such as finasteride (marketed as Propecia), which can delay, stop or even reverse baldness, while they still possess luxuriant locks. The research should also assist the development of new treatments. Professor Tim Spector, of King’s College London, who led the study, said: “Early prediction before hair loss starts may lead to some interesting therapies that are more effective than treating late-stage hair loss. It will encourage pharmaceutical companies to produce preventive lotions that might stimulate hair follicles before it’s too late.” Brent Richards, of McGill University in Montreal, Canada, who contributed to the research, said: “We’ve only identified a cause. Treating male pattern baldness will require more research. But, of course, the first step in finding a way to treat most conditions is to identify the cause.”

Tests for the genes are offered by deCODE Genetics, an Icelandic company that took part in the study, through its deCODEme personal genotyping service.
The findings, which are published in the journal Nature Genetics,also add to understanding of how baldness runs in families. One of the two DNA regions that is implicated controls a male hormone receptor and is carried on the X chromosome, of which men have just one copy that is always inherited from their mothers. This variant, which was already known, may account for the common observation that men often take after their maternal grandfathers in trichological matters. The second DNA region, which has been newly identified, is on chromosome 20, of which men have two copies, one inherited from each parent. This means that at least some of men’s susceptibility to hair loss is passed on by their fathers.

About a third of men are affected by male pattern baldness by the age of 45, and two thirds by the age of 60. It also affects women, though more rarely, and tends to lead to generalised hair thinning rather than the characteristic pattern of loss seen in men. The new research suggests that men with the two genetic variants have a 70 per cent or greater chance of going bald early, while those who carry neither have a chance of about 10 per cent. About 14 per cent of men have the two variants.

Apr 17, 2009

un test per scoprire l'alzheimer prima che colpisca

(da Repubblica)

Un semplice esame del sangue per scoprire in anticipo se piccoli disturbi di memoria sono segni di un normale processo di invecchiamento o si trasformeranno, invece, in qualcosa di più grave come l'Alzheimer. Uno degli aspetti più strazianti della malattia è proprio la difficoltà di individuarne per tempo e con certezza i primi segnali. Ora, grazie a una nuova ricerca scientifica, l'obiettivo sembra più vicino. 

In uno studio pubblicato su Nature Medicine un gruppo di ricercatori dell'università americana di Stanford ha identificato un gruppo di 18 proteine usate dalle cellule per comunicare tra di loro e che permettono di predire con un'accuratezza del 90 per cento se una persona svilupperà o meno la malattia. 

Esiste una connessione fra i cambiamenti che si verificano nel cervello di chi soffre di Alzheimer e il modo in cui le cellule comunicano fra di loro. Per i ricercatori, guidati dal professor Tony Wyss-Coral, il test che coglie le modificazioni in queste proteine è in grado di determinare se la malattia si svilupperà nei successivi due-sei anni, in anticipo quindi rispetto alla comparsa dei sintomi più significativi.  

I ricercatori hanno analizzato 259 campioni di sangue da diversi pazienti: alcuni colpiti dai primi sintomi della malattia, altri già a stadi conclamati e avanzati, altri ancora che non presentavano alcun sintomo. E, partendo da un gruppo di 120 proteine note per la loro attività di comunicazione fra le cellule, ne hanno individuate 18 chiave, specifiche, che sono espresse in concentrazioni diverse nelle persone malate di Alzheimer. Queste proteine sono anche implicate nella produzione di nuove cellule del sangue, nei processi immunitari e nella morte delle cellule al termine del loro ciclo naturale. L'ipotesi è che ci sia qualcosa di errato nell'informazione contenuta nel DNA e che porta alla produzione di determinate cellule del sangue che svolgono un ruolo importante nell'eliminare quei depositi che si accumulano nel cervello delle persone malate di Alzheimer. La diagnosi precoce rappresenta un'arma in più per combattere l'Alzheimer.

A 10-step guide to genetic testing

What is genetic testing? A type of medical test that identifies changes in the DNA. Tests can target gene mutations or variations of single nucleotides and can be used in diagnostic to find changes associated with inherited disorders or as a prevention to assess the risk in developing a certain disease. The results of the test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder.

What are the types of genetic tests? Genetic testing can provide information about a person’s genes and chromosomes. Available types of testing include:

·        Newborn screening used just after birth to identify genetic disorders that can be treated early in life.

·        Diagnostic testing – used to identify or rule out a specific genetic or chromosomal condition.

·        Prevention testing – offered to individuals who have a family history of a genetic disorder and to people in certain ethnic groups with an increased risk of specific genetic conditions.

·        Prenatal testing – used to detect changes in a foetus’s genes or chromosomes before birth. It is offered during pregnancy if there is an increased risk that the baby will have a genetic or chromosomal disorder.

·        Preimplantation testing – preimplantation genetic diagnosis (PGD), used to detect genetic changes in embryos created using assisted reproductive techniques.

·        Predictive and presymptomatic testing – used to detect gene mutations associated with disorders that appear later in life. Can be helpful to people with a family member with a genetic disorder, but who have no features of the disorder themselves at the time of testing. Predictive testing can identify mutations that increase a person’s risk of developing disorders with a genetic basis, such as certain types of cancer.

·        Forensic testing – uses DNA sequences to identify an individual for legal purposes.

How is genetic testing done? Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a foetus during pregnancy), or other tissue. The sample is sent to a laboratory where technicians look for specific changes in chromosomes, DNA, or proteins, depending on the suspected disorder. The laboratory reports the test results in writing to a person’s doctor or genetic counsellor.

What do the results of genetic tests mean? The results of genetic tests are not always straightforward, therefore it is important for patients and their families to ask questions about the potential meaning of genetic test results both before and after the test is performed. When interpreting test results, healthcare professionals consider a person’s medical history, family history, and the type of genetic test that was done. It is important to note that a positive result of a predictive or presymptomatic genetic test usually cannot establish the exact risk of developing a disorder.

What is the cost of genetic testing, and how long does it take to get the results? It can range from under $200 to more than $2000 (US Dollars), depending on the nature and complexity of the test. From the date that a sample is taken, it may take a few weeks to a few months to receive the test results. The doctor or genetic counsellor who orders a particular test can provide specific information about the cost and time frame associated with that test.

Will health insurance cover the costs of genetic testing? In many cases, health insurance plans will cover the costs of genetic testing when it is recommended by a person’s doctor. Health insurance providers have different policies about which tests are covered. A person interested in submitting the costs of testing may wish to contact his or her insurance company beforehand to ask about coverage.

What are the benefits of genetic testing? Genetic testing has potential benefits whether the results are positive or negative for a gene mutation. Test results can provide a sense of relief from uncertainty and help people make informed decisions about managing their health care. A negative result can eliminate the need for unnecessary checkups and screening tests in some cases; a positive result can direct a person toward available prevention, monitoring, and treatment options.

What are the risks and limitations of genetic testing? The physical risks associated with most genetic tests are very small, particularly for those tests that require only a blood sample or buccal smear. Most of the risks associated with genetic testing involve the emotional, social, or financial consequences of the test results. Genetic testing can provide only limited information about an inherited condition. The test often can’t determine if a person will show symptoms of a disorder, how severe the symptoms will be, or whether the disorder will progress over time. Another limitation is the lack of treatment strategies for many genetic disorders once they are diagnosed. A genetics professional can explain in detail the benefits, risks, and limitations of a particular test.

What is genetic discrimination? There is no risk of genetic discrimination when people undergo genetic testing by their employer or insurance company due to the G.I.N.A.

How does genetic testing in a research setting differ from clinical genetic testing? The main differences are the purpose of the test and who receives the results. The goals of research testing include finding unknown genes, learning how genes work, and advancing our understanding of genetic conditions. The results of these testing are usually not available to patients or their healthcare providers. Clinical testing is done to find out about an inherited disorder in an individual patient or family. People receive the results of their tests and can use them to make decisions about medical care or reproductive issues. Clinical and research testing must both involve a process of informed consent in which patients learn about the testing procedure, the risks and benefits of the test, and the potential consequences of testing.

Apr 16, 2009

a little bit of sun...a little bit of skincare

We all know that the sun's rays are becoming more dangerous over the years and the increased incidence of skin cancer (or melanoma) is one proof. Now researchers writing in The Lancet, a prestigious medical journal, have discovered the world's most effective sunscreen. Short of staying indoors, this method of blocking the sun's rays works better than any SPF product yet invented.  What is this great new product?  Wear proper protective clothing. 

 

Ah ah ah you say? Well, it turns out, there is a lot to learn about protective clothing, since more and more people are relying on it, and not all protective clothing is created equal.  According to the authors, the best protection comes from tightly woven clothing combined with a good hat. The study looked at different clothing and found that a light cotton t-shirt (probably the most frequently worn protection) actually only provides the equivalent of around SPF 10.  As importantly, the study found that a wet t-shirt affords less protection than dry, something that snorklers should take into account when protecting themselves from the sun. In general it appears, thickness, weight, color and porosity all matter - so if you are going to rely on clothing, make sure it's the right stuff.

 

For those (the vast majority of us) who somehow don't think a day at the beach is quite the same when covered head to toe, the authors have some other helpful hints:

  • Apply the sunscreen over your entire body in a uniform manner and don't skimp.  Barriers that are opaque, such as zinc oxide, work best
  • Any sunscreen that is organically based should be applied at least 15 minutes before exposure
  • Be sure to use sunscreens that are waterproof or water-resistant, and of course, the higher the SPF the better
And what if I have a sensitive skin and/or a predisposition to skin cancer?

Apr 15, 2009

the longevity gene

The successful completion of the human genome project is a great scientific finding and will bring about a big hopes for eternal life. As far as eternal life is concerned, the secret recipe is not hidden in some mystic place in the world, but lies in human genes. The reason is that for any given individual, the influence of genes in the lifetime is fundamental. Some species have a surprising long life (hundreds of years), while others have a very short life (less than one day); given that llifespan is fixed for each species, it is clear that lifespan is determined essentially by genes.  


Why is the lifespan longer in some and shorter in others? Genes play a basic role. Hence, by revealing the secrets of gene, we may find the golden key to longevity or eternal life. Although scientists have not been able to do large-scale studies on the “longevity gene” in an organized and planned way, the bit-by-bit studies have led to many discoveries. For example, they found the gene called “I have not died”, the “Methuselah gene” and so on.


 A research group in European Tumor Research Institute in Milan announced that they have found a gene related to the lifespan of an organism. By restraining the effect of such a gene, they could prolong the life of an organism. The researchers have found that after getting rid of a gene called “P66SHC” in the mouse, or restraining its functions, the mouse’s resistance to disease was strengthened and its lifespan greatly prolonged. Scientists in US Fornea Technical College found a drosophila that lives longer than other drosophilas, because there is a special gene functioning in it. Now, by using this gene they can prolong the life of drosophilas by 35%. This gene was names “Methuselah Gene”, following a figure in The Bible that lived to the age of 969. If such a gene in mankind can be found and made the best use of, we will be able to make man’s life time exceed Peng Zu - a Chinese man who lived to the age of 800 - or Methuselah. Scientists in Connecticut State University’s Medical Centre chanced on a new “longevity” gene in their research project on drosophilas. The main reason why this “longevity” gene can change drosophila’s lifespan is that it can control energy absorption of drosophila’s cells, as if they were in a “diet”. This gene is distributed on the two chromosomes of drosophila. If the gene is changed on only one chromosome, drosophila’s lifespan will extend by one time or so; but if it is changed on both chromosomes, drosophila will die of too much “diet”. This gene was named “I Have Not Died”. Scientists in Massachusetts Institute of Technology reconstructed the gene of a nematode and prolonged its life by more than a half successfully. If the nematode had two SIR2.1 genes, it that can only live for two weeks (originally it can live three weeks).  


The discovery of these longevity genes has brought about a fine prospect for mankind’s longevity. At Scripps Academy of California scientists did a research on genes of old people above 90 and they found that in more than 99% of the cases genes functions of these old people were completely normal, almost like the genes of neonates. Then, why do we still get old? Researchers in Illinois University at Chicago have found one answer. They say that the secret of aging might lie in a special gene called “p21”. By starting up p21 gene, we can cause significant changes in uncountable other genes, and all these genes have something to do with aging and diseases relevant to aging.” So, there must be genes in the human body that are closely related to longevity, and by a full and deep understanding of such genes and by regulating and modifying them properly, we might be able to reach the purpose of longevity or living forever. 


Genetic engineering also has a very important function: it can combine human genes, animal genes, vegetal genes or any species’ genes into one individual life. It is an earthshaking change, which may trigger the most profound and tremendous transformation, including extension of human life. As we know, some animals are long-living such as big turtles and many unicellular animals can “live forever” so long as the environment is suitable; also some plants are also long-living like ancient cypresses. If we could find the genes that help them live so long and then transplant or duplicate them for humans, or develop drugs with the same effect, then, we will open up the road of prolonging people’s life.  

Genetic engineering could trigger a series of revolutions, such as the magical genetic forecast, genetic diagnosis, gene therapy, gene reconstruction and so on, all of which have displayed an extremely bright prospect for the realization of eternal life. Most “incurable diseases” such as cancer will be eradicated and AIDS will not be worth mentioning. 


Genetic research has also shown that the main causes of aging might be related to the defects in the “maintenance” and “repair” systems of the human body, and such systems might be controlled by genes and therefore, by transforming or “closing” these genes, we might be able to control the aging process of mankind. For these reasons, the British scientist in charge of the genome project, asserts that it is not a hard thing for the average human lifetime to reach 1200 years or so. The continual breakthrough in gene research can not only prolong human lifespan, but also make people ageless. And as the Chairman of the Board of Directors of The Human Genome Scientific Research Company points out: “It is very likely for us to find out the headspring for keeping youth forever from our own genes. Cell replacement may be able to help people keep youth and health forever.”


(received by Anonymous and posted)

Apr 14, 2009

genetic disorders and genetic tests

As the secrets of the human genome are revealed, we're discovering that nearly all diseases have a genetic component. Some, including many cancers, are caused by a mutation in a gene or a group of genes that occur randomly or due to exposure to some environmental factor.

In other hereditary disorders - such as Huntington's or Tay-Sachs disease - a mutated gene is passed down through a family and each generation of children can inherit the gene that causes the disease.

However, most genetic disorders are "multifactorial" being caused by a combination of small variations in genes that act in concert with environmental factors.

Many common diseases usually caused by genetic alterations in the genome - such as breast cancer and colon cancer - have also rare hereditary forms. In these cases, gene variants that cause or strongly predispose a person to these cancers run in a family and significantly increase each member's risk of developing the disease.

Having said that, how can preventive genetic testing help?

personal genomics in europe

Following the booming of personalized genetics on the other side of the globe, I'm quite curious about the impact that personal genomic screening services might have, and probably will have, in Europe.

There are at least two considerations to make: first, Europe is less dependent on private health insurance, therefore, less tempted by DIY medical analyses; second, these tests seems to rely on an internet-based service that is not so diffuse in Europe, especially among southern countries. Will these barriers be enough to stop the wave of "trendy" personal genetic testing approaching our continent?