Other

The applications we’re about to cover are a bit different. They use molecular testing to answer more nuanced questions about a person’s biological identity and how that unique identity interacts with the world of medicine. Think of this as moving from finding a typo in the instruction manual to reading the whole manual to understand how the machine is supposed to function in different situations

Here is an overview of these four key areas

Histocompatibility

• The Big Idea: This is the study of the body’s cellular ID card system, the Human Leukocyte Antigens (HLA). These proteins sit on the surface of our cells and scream “SELF!” to our immune system. The HLA genes that code for these proteins are the most variable in the entire human genome, meaning your HLA “ID card” is almost completely unique to you
• The Application: We perform HLA typing to find the best possible match between a donor and a recipient for transplantation. The better the match, the lower the risk of the recipient’s immune system attacking the new organ (organ rejection) or, in a stem cell transplant, the risk of the new donor immune system attacking the recipient’s entire body (Graft-versus-Host Disease). It is the foundational test for all transplantation medicine

Genetic Identity

• The Big Idea: This is the creation of a definitive “DNA fingerprint” for an individual. We aren’t looking at genes that cause disease; instead, we analyze highly variable, non-coding regions of DNA called Short Tandem Repeats (STRs). By looking at about 20 different STR locations, we can generate a numerical profile that is statistically unique to one person out of quintillions
• The Application: While famous in forensics and parentage testing, its most critical role in the clinical lab is specimen identification. It provides an undeniable way to ensure a biopsy or blood sample truly belongs to the correct patient, preventing catastrophic diagnostic or treatment errors. It’s the ultimate tool for resolving sample mix-ups and confirming specimen provenance

Engraftment

• The Big Idea: This application perfectly marries the two concepts above. It’s the process of monitoring the success of an allogeneic hematopoietic stem cell (HSC) transplant. After a patient’s diseased marrow is wiped out, they receive new, healthy stem cells from an HLA-matched donor. We need to know if those new cells “took root” and are growing successfully
• The Application: Using the same STR testing from genetic identity, we analyze the patient’s blood post-transplant. We can see both the recipient’s and the donor’s DNA profiles. By quantifying the percentage of donor cells over time, we monitor chimerism. The goal is 100% donor chimerism. A drop in this percentage can be the earliest warning sign of impending graft failure or disease relapse, allowing clinicians to intervene

Pharmacogenomics (PGx)

• The Big Idea: This is the study of how a person’s unique genetic identity affects their response to drugs. It’s the key to personalized medicine. Our genes code for the enzymes that metabolize drugs, the receptors that drugs target, and the HLA proteins that can sometimes cause dangerous allergic reactions
• The Application: PGx testing allows us to predict how a patient will handle a specific medication before they take it. We can identify patients who will metabolize a drug too quickly (leading to treatment failure) or too slowly (leading to toxicity). We can identify if a cancer patient’s tumor has the right “target” for a drug, or if a patient has the specific HLA type that would put them at risk for a severe hypersensitivity reaction. This makes drug prescribing safer, more effective, and truly personalized