Why Geneticists are the Rockstars of Mystery Diagnosis
Have you ever seen Mystery Diagnosis? It was a TV show that followed people who had stumped many doctors before finally arriving at a diagnosis. In clinic, we call this journey “the diagnostic odyssey” and it can take years. When I was on maternity leave, I used to watch Mystery Diagnosis a lot. I would challenge myself to figure out the diagnosis before it was revealed on the show. Sometimes, I could even do it from the episode description! In the show, the “hero” of the episode was often a geneticist. So why are they so good at solving these medical mysteries?
They are “Jacks (and Jills) of All Trades”
The genome is the recipe for your entire body. A change in the genome could affect literally any part of your anatomy. Some genes encode proteins that are important in many different systems within your body. A single genetic mutation might cause problems in the brain, heart, and kidneys. So, while many medical specialists are experts in one system of the body (cardiology, neurology, gastroenterology), geneticists have to be familiar with everything. From the hairs on your head to the bones in your toes, geneticists have to understand all of it to identify rare genetic diseases.
They See Patients “from the Womb to the Tomb”
Just as genes can affect any part of your body, they can affect you at any point in your life. Some conditions can be identified on a prenatal ultrasound, while other’s may not reveal themselves until someone is in their 70’s. While some geneticists may work primarily in prenatal, pediatric, or adult clinics, they are trained to recognize conditions that can present themselves at any point in a person’s life.
They Have an Eye for Detail
Some genetic syndromes have features that are subtle. Sometimes a group of completely benign features can help lead to a diagnosis. A large head size; bumps on the palms of the hands; freckles on the lips; a certain type of birthmark — these seemingly unimportant details can be the final clues that help the geneticist figure out why a person developed cancer at a young age. Sometimes a genetic exam even involves measuring parts of the face! No detail goes unnoticed.
To Them, Rare is Common
There’s a saying in medicine that goes, “If you see hoof prints, think horses, not zebras.” In other words, the most common answer is probably the right one. However, most genetic diseases are zebras. Even the “common” genetic diseases are rare compared to non-genetic conditions. Some genetic conditions are so rare that most physicians may only see a few cases of it in their lifetime, if they ever do at all! But geneticists specialize in rare disease. While your pediatrician may have had a patient or two with Phenylketonuria (PKU) in their career, chances are that every person with with PKU in the whole tri-county area has been seen by the same geneticist. Because the conditions they work with are so rare, geneticists collaborate often to share cases and learn from each other’s experiences.
They Have Some Powerful Diagnostic Tools
Not too long ago, clinical genetic testing cost about $1,000 per gene. With the invention of Next Generation Sequencing (NGS), that cost has come down and the number of genes that can be tested has skyrocketed. Where as before it may have only been possible to test one or two of the most common genes for a certain condition, they now often test all of the known genes for a condition all at once.
For those cases that have the geneticist stumped, they can now order Whole Exome Sequencing (WES), which looks at each part of the DNA that codes for proteins, or even Whole Genome Sequencing (WGS) which looks at the entire genome. The interpretation of these tests is tricky, as they can find lots of things in the genome we don’t fully understand yet (can you say, VUS?), but they can often be the tool that helps solve the diagnostic odyssey once and for all.
They Don’t Go It Alone
As the old saying goes, behind every great geneticist is a great genetic counselor (or at least the saying should go that way). Geneticists and genetic counselors work hand in hand to assess, test, and manage genetic conditions. They often tag team to make sure the clinic runs as smoothly as possible and each patient or family has all their needs met. A good MD+GC team makes a great impact on the quality of care a patient receives.
As genetic evaluation and testing becomes more integrated into healthcare as a whole, the need for clinical geneticists is higher than ever before. Unfortunately, there is a shortage of both clinical geneticist and genetic counselors. If you’re interested in genetics, consider becoming one of these rockstars yourself. We need you!