An Everyday DNA blog article
Written by: Sarah Sharman, PhD
Illustrated by: Cathleen Shaw
Human disease has been part of our story for as long as people have walked the earth. We’ve always wrestled with illness and searched for ways to understand and overcome it. Even in texts dating back nearly 5,000 years, we find descriptions of fevers, seizures, and conditions that feel surprisingly familiar.
Early physicians and healers relied their own senses, studying the skin and eyes, listening to the rhythm of breathing and pulse, and even examining taste or smell in bodily fluids. Over time, simple instruments expanded human perception: water clocks timed a pulse and magnifying lenses revealed hidden detail.
Progress has always depended on two pillars: deeper knowledge of the body and technology that reveals what the eye alone cannot see. When those two forces intersect, diagnosis leaps forward. Today, genetics sits at the heart of that next leap, making answers faster, clearer, and more personal.
A Disease Seen Three Ways: Diabetes Through the Ages
To trace this evolution, let’s follow one condition across time. Imagine three people, centuries apart, all with the same classic symptoms: excessive thirst, weakness, and unusually frequent urination.
100 AD: Sweet Urine and Ant Trails
Tiberius, a wealthy Roman merchant, visits his physician. A urine sample smells sweet, and when left outdoors, it attracts a swarm of ants. These simple observations confirm a diagnosis of diabetes. The physician doesn’t know about the pancreas or insulin, but recognizes something is out of balance. Treatments are limited, but naming the disease marks progress: a consistent observation tied to a specific illness.
1850s: Chemistry Brings Objectivity
Centuries later, Elizabeth, a young woman, has been unwell. Her physician takes a urine sample and adds Benedict’s solution, a new chemical reagent. When heated, the mixture shifts to a cloudy orange, indicating sugar is present. For Elizabeth, treatment options are still limited, but the diagnosis has moved beyond human senses to chemistry, a small but powerful shift toward objectivity.
2025: Numbers, Antibodies, and Precision
Martin visits his primary care doctor. His doctor orders two quick blood tests: a fasting glucose and an A1C, which reveals blood sugar levels over several months. Additional lab work identifies antibodies that distinguish between Type 1 and Type 2 diabetes, guiding a customized treatment plan. Diagnosis is now precise, measurable, and deeply informed by biology.
Looking Beneath the Symptoms: Why Genetics is a Turning Point
Diabetes shows how far we’ve come, but many diseases are less straightforward. Their symptoms mimic others, appear late, or remain buried in our DNA. For centuries, doctors could describe what they saw but not uncover the hidden cause, like spotting smoke but not the fire. Genetics changed that.
Cancer: Reading the Mutations That Drive Growth
At its core, cancer is a genetic disease caused by mutations in DNA that encourage cells to grow uncontrollably. Once, cancer was categorized by where it showed up, like breast, lung, or colon. Now, whole-genome sequencing reveals the mutations that drive cells to multiply uncontrollably. Two people with lung cancer may actually have very different diseases at the DNA level, requiring different treatments. Genetics shifts care from one-size-fits-all to tailored precision.
Neurodegenerative Disease
Conditions such as Alzheimer’s disease, Parkinson’s disease, and ALS have long resisted clear diagnosis. Symptoms often appear late in life, overlap with other disorders, and progress slowly. Doctors historically diagnosed by exclusion, ruling out possibilities rather than pinpointing a cause.
Genetics is changing that. By scanning DNA, scientists can identify changes in DNA that either increase risk or directly cause specific forms of neurodegenerative disease. These insights not only speed up diagnosis but also guide research into targeted therapies. For families, genetic clarity helps anticipate disease course, plan care, and connect with clinical trials aimed at specific mutations.
Neurodevelopmental Disorders
Children with seizures, developmental delays, or atypical growth patterns often faced the “diagnostic odyssey”—a long maze of tests without clear answers.
Whole-genome sequencing now reads every letter of a child’s genome in a single test. Often, it reveals the rare mutation responsible. Even when treatments remain limited, a genetic diagnosis brings validation, helps tailor care, and connects families with research and support networks. For parents, the answer is more than a label—it’s finally knowing the “why” behind their child’s illness.
The Power of Genetics
Modern genetics makes it possible to connect symptoms to their underlying causes, even in rare or complex diseases. With a single test, whole-genome sequencing can scan nearly all 20,000 human genes and the vast regions that regulate them. Advances in computing sort through this data in ways no human could, while ongoing research helps clinicians interpret what the patterns mean for patients.
This convergence of discovery and technology is what makes today so exciting for medicine. Where diagnosis once meant observing the surface, it can now reach into DNA itself, uncovering the root causes of disease.
HudsonAlpha’s role in advancing genomic health
At HudsonAlpha Institute for Biotechnology, we’re working to translate this revolution into real-world answers. Our scientists use genomic technology to tackle cancer, rare childhood conditions, and neurodegenerative diseases like Alzheimer’s, Parkinson’s, and ALS.
Diagnosis is just the beginning. Understanding genetic blueprints opens doors to better treatments, prevention, and truly personalized medicine. Pairing genomic insight with compassionate care moves us toward a healthcare future where answers are clearer and treatment paths more effective.
The story of medicine has always been the story of expanded sight. Ancient physicians once relied on the senses. Chemistry revealed measurable biomarkers. Microscopes opened cellular worlds. Now, genomics unveils the code that underlies them all.
The future of diagnosis won’t stop here. One day, sequencing the human genome may become as routine as checking blood pressure. With each discovery, possibilities multiply, for earlier diagnoses, more precise treatments, and perhaps even prevention before illness begins.
History reminds us: progress happens when discovery and technology meet. With genetics, we’re entering the next great chapter of that story, one that is already transforming medicine and bringing new hope to families around the world.
