Whole genome sequencing
and the future of medicine: A discussion of policy implications ranging from
genome privacy to designer babies.
The presidential race of 2016 was tight. That is, until
information was leaked that Hillary Clinton has a genetic predisposition to early
onset Alzheimer’s disease. How her genetic info was obtained is unknown; her
campaign staff followed strict protocols to collect and destroy everything she
touched – toothbrushes, bed sheets, cups. It may be that years before she was a
candidate, a cunning opponent attended her book signings and patiently
preserved the pages she penned until the moment was ripe. But the method and
legality of the leak is irrelevant. Unlike in a jury case, one can’t instruct an
entire electorate to ignore information that may have been illegally obtained.
Thus began a new era of American politics: no longer was it simply video or
written evidence of your past that was under scrutiny. Now, the DNA code
prophesizing your future was also campaign material.
Presently, the above scenario might sound like science
fiction. But an emerging technology called whole genome sequencing (WGS) is poised
to blur the distinction between imagination and reality. WGS is the ability to
decode the entire DNA sequence that makes an individual unique. While this
technology is still too expensive and cumbersome to be applied on a population
scale, the cost-per-genome is
dropping at an astounding rate, much faster than has
occurred with computing power.
WGS is beginning to enter the clinic as more
physicians use it to help with diagnosis and treatment determination, but policies
related to WGS are still in their infancy. In May, the Penn Science Policy
Group gathered to discuss the emerging use of WGS and the implications it will
have for medicine and society.
Privacy is a huge concern. One’s genome is like their
medicine cabinet, except it reaches both backward into the past and forward
into the future. The opening scenario
might seem a little dramatic and highly specific, but there are already
indications showing that government officials take measure to protect the President’s
DNA and collect DNA samples from foreign leaders. Scenarios can be envisioned within the lives
of civilians, too. Imagine a child custody case in which WGS showing a parent’s
predisposition for cancer or neurological disease is used as evidence against
their fitness for parenting. The Genetic
Information Nondiscrimination Act of 2008 (
Pub.L.
110–233, 122
Stat.
881, enacted May 21, 2008,
GINA)
was enacted to prohibit the use of genetic information in employment and health
insurance situations.
However, it does
not cover life insurance or long-term care insurance, which is already proving
problematic for some.
How
this law would apply to genetic sequencing obtained covertly or used for
persuasion in civil courts or the public sphere is unknown.
Even consenting to
undergo WGS has some privacy risks.
A
study published this year re-identified 50 individuals from de-identified
genetic sequences using public access information like age and surname.
Although the group of samples used represents a low hanging fruit for such
hacking, it demonstrates the need for more focus on protecting anonymity of
sequencing information.
A 2012
report to the
President indicated that stronger baselines for privacy of WGS data are needed. Privacy protections at the state level are
inconsistent. And although samples collected through federal agencies like the
NIH and CDC have federal laws mandating confidentiality, privacy, and security,
“currently, there are no overarching federal or industry guidelines indicating
how commercial genetic testing companies should operate, what privacy controls
they should implement, or what limits they should put on the use of genetic
data and information.”
One hotly debated topic
is the ethics of incidental findings from WGS. When a physician orders WGS
because it may help explain a patient’s particular medical condition, they are
“looking” for relevant information. However, many more things may be found in
the genome that are not relevant to the original reason it was ordered, but may
have health consequences for the patient or their family members. These consequential discoveries are known as
incidental findings.
What happens when
results incidentally find that a patient carries the gene for Huntington’s
disease? Or a gene that predisposes them to colon cancer? Or for adverse
reactions to certain anesthetics? Recently the American College of Medical
Geneticists published
recommendations urging that every WGS result be analyzed
for the presence of mutations in 57 genes that are highly predictive of
diseases with actionable interventions.
ACMG recommends these findings be reported to the patient regardless of
consent and age (includes children), and the patient’s only chance to not
receive this information is to decline sequencing.
Opponents argue that this practice goes
against patients’ right to refuse unwanted medical tests and information, even
if it might be beneficial.
Opinions on this topic among PSPG members were diverse and conflicted, which showcases
the need for thorough public discourse on this issue.
Additionally, there are applications of WGS that warrant discussion.
Even seemingly benevolent intentions, such as preventing genetic disorders, can
conjure up fears of a deterministic society rife with prejudices based upon
genetic identity. The 1997 movie Gattaca
portrays a grim vision of the future where fertilized embryos are screened to
deliver babies with desirable qualities like a certain gender, perfect vision, and
resistance to addiction. Children born naturally are considered invalids and
forced into a working class that supports the more glamorous careers of those
with superior genes.
But this scenario is pretty far-fetched, right? Actually,
not quite. A technique called preimplantation genetic diagnosis (PGD) already
exists to enable carriers of certain genetic disorders to have healthy babies –
the
first child born from this procedure is now 23 years old. The real concern
is that this technology will be used beyond preventing terrible diseases to
selecting merely preferential traits. Some countries have enacted laws to
prevent this application, such as the UK and Canada, but in the US there is no
federal regulation of PGD. In fact, some parents have even purposely
selected
for children that are deaf.
The two largest obstacles for widespread use of PGD are the cost (it must be
combined with in vitro fertilization) and our lack of knowledge about the complex
genotypes that determine many of the desirable qualities depicted in
Gattaca. However, given the pace at
which science and technology move, these possibilities should not be
underestimated when considering policies for the future.
When the first human genome was sequenced, a wave of
excitement rushed through the media as it anticipated a new era of medicine,
one that was tailored to the uniqueness of our individual genetic identities.
In a word: “personal.” Personalized
medicine has thus far been a disappointment, but that should have been
anticipated. Only when the cost of
genome sequencing and analysis drops to a point where it can become commonplace
can we expect to benefit from its potential.
Will WGS reach the tipping point soon and become a standard
part of medical practice? It seems that although the cost is dropping, other
limitations exist that will limit widespread integration of WGS in the near
future. Many of the biologists in our group identified the bottleneck of WGS as
the analysis and interpretation of genomic data. Trained professionals that can
interpret and communicate this massively complex information are at a premium,
and the clinical interpretation is still mostly meaningless. Nearly every
genetic association identified with common diseases is too
insignificant to be
clinically useful.
As a result, right now genomic data is more confirmatory than predictive. That
is, knowing a patient’s DNA sequence is useful in diagnosing the cause of a
disease, but rather useless in predicting whether or not it will develop. WGS
on a newborn is not a crystal ball, yet still this information could assist in
medical care throughout a person’s lifetime, making it an attractive companion
to a patient’s medical record that will become more valuable as science
progresses.
Although maybe not for another decade, we will eventually
see the tools, professions, and knowledge of WGS progress to the point where it
transforms medicine and everyday life. Current policies regarding WGS are
lacking, varied, or incomplete. Federal regulations are needed that ensure
security, privacy, and informed consent of WGS and restrict its malicious use
while protecting the liberty of individuals and the benefits obtained from it.
A future of personalized genetics is inevitable; it is our duty now to ensure
we enter a future that uses WGS for minimal harm and maximal gain.
