For a family navigating a rare or genetic disease, a diagnosis can be life-changing. After months or even years of appointments, tests, referrals, and unanswered questions, finally understanding what is causing a child’s symptoms brings families an answer they have often been searching for too long.
But an answer is not the end of the journey. It is the beginning of better care, and that distinction is fundamental to the promise of genomic medicine. The value of a diagnosis is what clinicians and families can do differently because they have it: Make more informed treatment decisions, anticipate complications, avoid unnecessary care, and connect patients with the right specialists, resources, and therapies.
We know genomic testing can find answers. But what do we do differently once we have them?
FROM INFORMATION TO ACTION
Medicine works best when we understand what we are treating.
Yet too many children with suspected genetic conditions still receive care without that fundamental information. Clinicians manage symptoms while searching for an underlying cause, often ordering tests and making treatment decisions based on an incomplete picture.
A molecular diagnosis gives clinicians actionable information. It can inform decisions about medications, surveillance, referrals, procedures, and long-term management.
In epilepsy, for example, identifying the underlying genetic cause can influence which medications a clinician chooses or avoids, what complications to monitor for, and whether a patient may be eligible for a targeted therapy or clinical trial.
The same principle applies across rare and neurodevelopmental conditions. Once we understand the cause, we can move beyond managing the symptoms and plan for what a patient needs next.
IMPACT BEYOND THE EXAM ROOM
A diagnosis also changes what is possible for families.
Parents who have spent years moving from specialist to specialist finally have a framework for understanding their child’s health. They can make more informed decisions about
therapies, educational services, specialists, and long-term planning. They can connect
with other families living with the same condition and with advocacy organizations that
understand their experiences. Finding others who are going through similar journeys can be
validating and helpful. In rare disease, it is challenging to find people who can relate
to these medical and emotional experiences.
The positive impact of a diagnosis does not always require a breakthrough therapy. A diagnosis can change care today, leading to something as straightforward as a nutritional intervention, targeted surveillance, or occupational or physical therapy. At the same time, a growing number of gene therapies and other precision treatments are creating new possibilities for patients.
But precision therapies require precise diagnoses. We can develop extraordinary new medicines that change lives only if we identify the patients who can benefit from them.
The impact can extend beyond the patient in ways families never anticipated.
Rosie Hopper’s story shows what that can mean for a family. Rosie had been diagnosed with cerebral palsy following complications at birth, but as she grew, bilateral hearing loss and other clinical clues suggested there might be more to the story. At age five, trio exome testing (testing the biological mother and father as well as the child) through our company identified a rare neurogenetic condition, providing a more complete explanation for her symptoms and helping inform her future care.
The testing also uncovered inherited BRCA1 and PKP2 variants with implications beyond Rosie. Those findings led to cardiac monitoring and earlier cancer-risk screening for Rosie, a preventive double mastectomy for her mother, and cardiac evaluation and ongoing treatment for her father. One diagnosis provided an answer for Rosie and changed care for an entire family.
BETTER INFORMATION CAN AFFECT OUTCOMES
The impact of diagnosis is also visible in how patients interact with the healthcare system.
Real-world evidence presented at the 2026 American College of Medical Genetics and Genomics Annual Clinical Genetics Meeting, from a GeneDx-led study combining genomic testing data with real-world healthcare claims data from Komodo Health, found that children with neurodevelopmental disorders experienced fewer hospitalizations and emergency department visits in the year following exome or genome sequencing.
When clinicians understand the underlying condition, they can shift from reactive care to proactive management. They can establish appropriate surveillance, coordinate specialists around a shared diagnosis, and potentially avoid unnecessary tests, procedures, emergency visits, and hospital stays.
THE NEED TO MEASURE WHAT HAPPENS NEXT
For years, much of the conversation around genomic testing has focused on diagnostic yield: How often does testing provide an answer?
While an important measure, it is no longer enough.
The next measure of success is what happens because a patient received that diagnosis.
- Did it change treatment or monitoring?
- Did it eliminate unnecessary tests or procedures?
- Did it connect the family with specialists, support, research, or a clinical trial?
- Did it help clinicians anticipate complications before they became emergencies?
- Did it lead to better care?
These are outcomes that demonstrate the full value of genomic medicine.
DIAGNOSIS IS THE FOUNDATION OF CARE
Genomic sequencing, AI, and precision therapies are rapidly changing what is possible in medicine. But each of these advances depends on something fundamental: understanding the underlying cause of disease.
There is no precision medicine without precise diagnosis.
That is why diagnosis cannot be the finish line. It is the foundation for what comes next: better decisions, more targeted care, and, increasingly, treatments designed for the specific biology of disease.
A diagnosis provides an answer and it changes what happens next.
Linda Genen, MD, MPH, is chief medical officer of GeneDx.
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