This is why doctors consider precision of medicine to be the future of health care
Meredith Newman
STRASBURG, PENNSYLVANIA — Tucked among the acres of farmland in Amish country is a clinic that treats its patients in ways that may be a harbinger of medicine's high tech future.
The Clinic for Special Children and its 17-person staff analyze the intricacies of its patients’ DNA to determine the best course of treatment. In some cases, the clinic has been able to personalize care based on genetic testing to the point that a child doesn't suffer from a brain injury or have to depend on a wheelchair.
Most impressive: The non-profit clinic doesn’t take insurance or federal grants. And it makes sure the prices of its services are affordable for the families of the sick Amish and Mennonite children it treats.
For decades, the clinic has been practicing a type of patient-specific medicine that major U.S. health systems are just now gearing up to do.
'In the not so distant future'
Hospitals are investing in genomic medicine as a result of the developments that make DNA sequencing faster and less expensive.
Decades ago, it would take 10 years to sequence a human genome. Now, it takes 24 hours. The cost has also dramatically decreased as more companies have entered the market, said Dr. Kevin Strauss, medical director of the Clinic for Special Children.
The difference in treatment and outcome can be startling. Instead of picking treatments based on the average responses of a large population, doctors can look at one person's genes and decide whether a specific medicine or treatment will be best.
Genetic testing has enormous potential in cancer alone and is already helping doctors decide what kind and how much chemotherapy and radiation patients need. For example, the University of Pennsylvania's health system is about to start DNA testing for heart disease.
It’s the kind of work Nemours/A.I. duPont Hospital for Children hopes to continue and expand on with its clinic for Dover’s Amish community.
“In the not so distant future,” Strauss said, “we will look at the genetic code of any individual as a vital tool or vital beacon that allows us to more intelligently, more rationally and more safely guide every aspect of their care throughout the arc of their lifetime."
The human genome
Genetic diseases stem from mutations that appear in a person’s DNA, which is a self-replicating material that looks like ladders of genes.
Those genes are made up of DNA, which consists of four chemical bases. When combined in various ways, they determine not only height, eye color and body type, but also the mechanisms for making protein and enzymes the body needs to grow and operate correctly.
When there’s a change in a code’s expected sequence, it's known as a genetic mutation.
As a result, the protein in the gene will not function properly — sometimes not at all — and cause disease.
With 20,000 to 25,000 genes in a single human body, finding that one problem can be difficult.
Most genetic diseases are hereditary — meaning they are passed from a parent to a child and therefore present in every cell in a person’s body.
Some genetic diseases can be acquired, meaning they are caused by environmental factors such as smoking or ultraviolet radiation from the sun. That kind of problem only occurs in a group of cells, not the entire body, but can grow to be devastating.
The founder effect
The Amish population has an increased likelihood of having hereditary genetic mutations because of the “founder effect,” Strauss said.
Only about 80 Amish people survived the migration from Europe to America in the 18th century. Because the community intermarries, there’s a limited and crisscrossing gene pool among the 330,000 Amish living in the United States.
Some resulting genetic mutations are exacerbated by the fact that about 85 percent of Amish children stay and marry within the community, rather than marrying outsiders and bringing in new bloodlines.
Some of the illnesses the Amish face do not affect people outside the group because they don't have the same concentrated genetic heritage.
Responsive, rather than reactive
That heritage allows the Clinic of Special Children to make “prescient diagnoses” for its patients based on DNA testing, Strauss said.
“It opens up this window of opportunity to prevent those sicknesses from even happening,” he said. “It allows you to take a responsive stance to their health care needs, rather than reactive.”
Strauss said the clinic can diagnose 150 genetic disorders and, through blood tests, can often make diagnoses before a baby is two hours old. The clinic's operating budget is about $2 million.
One example can be seen in a disorder called Ornithine transcarbamylase (OTC) deficiency, which is a rare metabolic disorder that can cause severe brain damage.
Before genetic testing, a diagnosis would come only after a child has gone into a coma. Now, doctors can tell if a baby has the disease. And if the baby does, doctors can advise certain dietary restrictions or give them medicine that will protect the brain and avoid any serious symptoms.
The clinic has also been able to reduce a condition called Maple Syrup Urine disease in the Lancaster community by 95 percent. The condition, which is known for making an infant’s urine smell like maple syrup, can consist of serious symptoms like seizures. If untreated, it can lead to death.
A common form of treatment is avoiding foods with a high amount of protein
By catching it in newborns before symptoms appear, the Amish Lancaster community saves about $8 million every year in hospital costs.
What this means for us
Amish heritage often also means that an illness seen in one group of Amish, say those in Lancaster, is not seen in others, such as the Dover group.
Because the Clinic for Special Children has been in practice for more than 20 years, the doctors have an idea of most of the genetic diseases in the community, Strauss said. Nemours doctors are only in the early stages of learning what genetic diseases are common about the Delaware Amish.
Erin Crowgey, research associate director of bioinformatics at Nemours, has developed a DNA test that will screen for 1,300 genetic mutations. They hope every U.S. clinic that treats Amish communities will use the test. The cost of the genomic sequencing and analysis is about $150.
The researchers use the same technology to help children with cancer.
'Genetics first'
In recent years, genetic testing has become a larger part of cancer diagnoses and determining forms of treatment.
Dr. Daniel Rader, chair of genetics at Penn’s Perelman School of Medicine, said Penn’s health system will soon offer genetic testing for heart disease.
In the past year, Penn Medicine has opened the Center for Precision Medicine. The hope is for doctors to take a “genetics first” approach when treating patients, Rader said.
“It’s doing genetic testing when appropriate in people, identifying genetic risk of disease and then doing something about it to prevent the disease from happening,” he said.
If a 38-year-old patient, for example, has a slightly high cholesterol level, doctors could use this test to see the patient’s risk for heart disease, Rader said. If it’s high, the person could go on medication, possibly preventing a potential heart attack later in life.
The long road ahead
Yet even advocates of precision medicine admit there is a “long way to go,” Rader said. Many in the larger medical community aren’t convinced about the value of performing genetic testing on healthy people.
It’s difficult to have studies show genetic testing helps prevent disease, since many of those occur in patients decades later, he said.
Genetic testing can raise issues when it comes to insurance. The Genetic Information Nondiscrimination Act makes the use of genetic information illegal when it comes to employment and health insurance.
But, this doesn’t apply to disability or life insurance, Rader said.
If a person filling out a life insurance application is asked about a certain disease, they might feel obligated to answer in a specific way due to their genetic testing results. This could potentially impact the quality of their life insurance.
Strauss, medical director of the Strasburg clinic, believes the cost isn't the only factor preventing hospitals from practicing precision medicine.
The U.S. health system doesn’t usually reimburse for genetic testing, he said. And physicians also don’t have the amount of time needed to discuss the results, since many practices rely on seeing a high volume of patients.
Contact Meredith Newman at (302) 324-2386 or mnewman@delawareonline.com and on Twitter @MereNewman.
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