Genetic testing has been with us for a century. It began with blood typing and tests for metabolic disorders like phenylketonuria (check the warning label on a can of Diet Coke), and by the mid-20th century we’d progressed to clinical cytogenetics. Chromosome spreads on a slide helped diagnose aneuploidies such as Down Syndrome (trisomy 21), sex chromosome disorders, and diseases like chronic myelogenous leukemia (via the Philadelphia Chromosome). For diagnosing and characterizing chromosome-level ailments, this was the golden age.
Well, that was fast
In 1985, revolution arrived in the form of the first sequence-based genetic tests. They spread like wildfire. Within a year, restriction fragment length polymorphism (RFLP) analysis hit the market and DNA-based evidence helped acquit a teenager of rape charges in the United Kingdom. In 1987, Tommie Lee Andrews of Florida became the first person convicted based on genetic evidence. Genetic tests were developed to diagnose single-locus ailments like cystic fibrosis and sickle-cell anemia. Forensic laboratories genotyped to identify killers and rapists, while innocence projects the same tests to exonerate prisoners (some on death row). The voyeuristic trauma of paternity testing became regular fodder for daytime talk shows.
Techniques like RFLP and single-locus genotyping made use of polymerase chain reaction (PCR), the new and paradigm-shifting technique for rapid synthesis of short DNA fragments. Though PCR revolutionized the notion of genetic testing, it was only at the close of the 20th century that scientists could realistically ponder the promise and perils of an even sweeter plum: genome-wide testing. With the completion of the Human Genome Project ten years ago, we began to fathom the era of personalized genomic medicine. Today, the race is on for the $1,000 genome.
Drinking from the fire hose
Researchers and medical doctors are still trying to figure out what sort of role whole-genome sequencing will play in 21st century health care. We know of many variants that cause or contribute to diseases (such as alleles at the infamous BRCA loci). However, there are huge gaps in our understanding of the complex interactions between genotype and phenotype. The pace of NGS projects, even in the nascent personalized medicine industry, may be too rapid for scientists and physicians to translate genome data into prognoses and treatments for patients. As patients, we ask for a simple trickle of information (“Am I going to get a disease?”), and our caretakers must divine the answer by drinking from the genomic fire hose.
Good luck with that
Beyond deciphering answers from NGS data, there are obvious security, privacy, and confidentiality concerns regarding the use and release of these data in a clinical setting. The ethical issues surrounding the use of NGS data are complex, profound and will have far-reaching consequences for all of us. Some of the questions facing us all include;
What laws govern use of clinical NGS data?
What about patient privacy?
Who, ultimately, is responsible for the safety, integrity, and privacy of genomic data in the age of genomics?
Join us for the second part of this article where we’ll try to tackle and answer some of these moral dilemmas.