Genomics: First part


Transition of genomics from lab to the world

Genomics vs Ethics.

Are they really opposite to such a degree that we have to pick sides?

Between statements such as “genomics is the promise for the future” and overblown statements about designing babies, not much has been said about influence of genomics on human lives.

Thirteen years were needed to sequence the complete human genome for the first time. It took us almost as much to bring the new generation sequencing to patients, doctors and people who care about their health.

The right time to start using genomics in clinics and in every day practice isn’t in 10 years. The right time is TODAY.

This post is the first in a series of posts which will present examples of effective usage of advanced genetic tools in curing people.

We have a weapon to fight (Non)Diagnosis

“Although doctors are devoting their lives to helping people get better, they seem to find a strange satisfaction in seeing a disease take its expected course” – Michael Kingsley, american political journalist and commentator.

Rare genetic diseases have been inaccessible for diagnosis and treatment for years. Only hospitals employing a “Dr. House” could have any success from time to time.

It’s the advancement in genomics and next generation sequencing that made opening of the big black box possible…

…molecular understanding of rare mitochondrial diseases raised from 1% to 60%. It will be a rare case that the genetic background of every of the 7000 Mendelian disorders (genetic disease which follows simple Mendelian patterns of inheritance like autosomal dominant and autosomal recessive disorders) is resolved.

What does this mean for those suffering from these rare diseases and for their families?

  • People who were looking for their diagnosis for years have 25%-50% chances to discover what is causing their problems.
  • In many cases, for their newly discovered disease there is already a cure that will help them live better and reach senior age.
  • If there is no cure that can help them, they can engage in studies and actively seek the cure for themselves, like Australian endurance athlete Kim Goodsell did.

To illustrate just how much new genetic tools can be effective in diagnosing and treating rare genetic diseases, take a look at this short video about a family of a boy which life was changed by having his COMPLETE EXOME (part of the genome which codes proteins) SEQUENCED.

I suppose that at least once in our life we witnessed a similar case (with not quite as a happy ending like that). At least 5% of world population doesn’t know the diagnosis for their disease. Luckily, for the first time we have a “weapon” to fight this global problem

Revolution in prenatal testing

One of commercially most successful “innovations” in field of applied genetics are NONINVASIVE PRENATAL TESTS (cell free DNA tests). These tests can recognize anomalies on chromosomes of a child from a sample of mother’s blood.

That enables accurate distinction of the following anomalies as early as in 10th week of pregnancy:

  • Down Syndrome (Trisomy 21)
  • Edwards Syndrome (Trisomy 18)
  • Patau Syndrome (Trisomy 13)
  • Trisomy 22
  • Trisomy 16
  • Triploidy
  • Aneuploidy on sex chromosomes

Traditionally, a procedure called amniocentesis, which is more extensive and accurate, was used. Problem with this traditional method was that it implied taking sample from the uterus with a needle, and it was a cause of abortion in one of 400 cases.

The goal of noninvasive prenatal test isn’t to replace amniocentesis, but to be used for pretesting and prevent unnecessary risk for women bearing perfectly healthy babies.

An old folk saying says: “Dust goes up in the air only after a good horse”. That same can be said for this test, as it caused many controversies and opposite opinions. To tell the truth, this test will leave most of them in the dust behind.

growth of noninvasive prenatal testing chart

In an interview for Medscape, Dr. Diana Bianchi says that this test reduced the number of amniocentesis performed by 50%. Over 1 million of women was tested using noninvasive prenatal test.

Doctors cannot know exactly how a will patient react to a drug, or can they?

“The goal is to deliver the right drug at the right time in the right dose to the right person, and eliminate treatments that don’t work.” – Richard Weinshilboum, M.D., director of Mayo Clinic’s Pharmacogenomics Program.

If there is any field where applied genomics can give direct results, then that would be PHARMACOGENOMICS. It’s regarded that genetic factors greatly influence on the way metabolism reacts to a drug (20% – 40%). For some drugs, influence of genetic factors is the most important factor.

Examples of how genes can affect the effectiveness of therapy either in a positive or negative way:

+ A person that has IL288 gene and as therapy uses interferon-@ for hepatitis C, has up to 38 more chances to cure this viral infection.
A person that has HLA-B*5701 gene and as therapy uses Flukloksacilin for inflammation or infection, has 80 times more chances to poison his liver.

 

These aren’t solitary examples, DNA structure for more than 150 drugs in America is already discovered. Those are drugs used in various fields of medicine, from painkillers such as Ibuprofen to less common drugs used in psychiatry and cardiology.

We are accustomed to being asked by doctors questions like: “are you allergic to any drug”? Imagine that besides that, a doctor can see how every treated individual will react to a drug he wants to prescribe, and based on that, decide on dosage or change it for another drug if necessary.

As much as this sounds applicable, there is only a few examples of using Pharmacogenomics in clinical and every day environment. I’d like to mention INoVa hospital that offers to parents of each newborn baby a free PX TEST (test that predicts how a patient will react to therapy, based on gene interaction).

It’s interesting how 80% of parents accepted this opportunity to provide a safer future for their kids, and disregarding various marketing propaganda based on ethic and safety concerns regarding this test.

Wrap-up

Full genomic transition from laboratory research to our lives will be a long process.

Having in mind that governments and insurance companies will do everything they can to slow this process down, initiation for using advanced genetic tools has to be done by clinics who take care of their patients, and by common people who take care about their health.

VeritasGenetics recently published that complete genome sequencing and results interpretation will cost you less than 1000 dollars. This means that very soon there will be no geographical nor financial boundaries.

The only boundary or limitation can be lack of knowledge or desire.