We Drew This Line Once

In 2008 Congress passed a law almost nobody remembers. The Genetic Information Nondiscrimination Act. GINA. It said a health insurer cannot look at your genes and use what it finds to deny you coverage or raise your premium, and an employer cannot use it to decide whether to hire you. Your DNA, and what it predicts about the diseases you might one day get, was placed off-limits to the people who price and ration care.

Think about what that law assumed. It assumed a prediction about your future health is different from your health today. You are not sick. You carry a gene that says you might become sick. Congress decided that gap, between what you are and what you might become, was dangerous enough to wall off by statute. Predisposition was not to be treated as disease.

GINA drew the line in a specific place, and the place matters. It protects your genotype, not your phenotype. It protects you while you are asymptomatic. The moment a condition manifests in your chart as a diagnosis, GINA no longer applies, because now it is simply your health, and insurers have always been allowed to price that. GINA also never covered life insurance, disability insurance, or long-term care insurance. In those markets your genes remain fair game.

So the law left a narrow territory protected: predictions of future disease, drawn specifically from DNA, in specifically health insurance and employment. Everything past those lines stayed open.

Continuous health monitoring walks straight into the open ground.

A trajectory is a prediction of future disease. Not from your genes. From your data. Your kidney function has been drifting for three years, still inside the normal range, but the direction is unmistakable and the endpoint is calculable. You do not have chronic kidney disease. You have a signal that says you are going to. That is not your genotype. It is not a manifested condition either, because nothing has manifested. It is the exact thing GINA was built to protect, a prediction of what you might become, produced by a method the law never imagined and does not cover.

You might think this is a worry about something that has not happened. It has already happened, in the cruder form the technology allowed.

In 2023 ProPublica reported that Cigna had built a system its own doctors called PXDX. It let company physicians reject claims in batches without opening the patient file. Over two months, Cigna doctors denied more than three hundred thousand requests, spending an average of 1.2 seconds on each. One-point-two seconds is not enough time to read a name, never mind a file. One medical director denied sixty thousand claims in a single month. "We literally click and submit," a doctor told them.

That same year, STAT News reported that UnitedHealth was using an algorithm called nH Predict to decide how long elderly patients could stay in rehabilitation, and to cut off payment when their care ran past what the model predicted. A class action followed, alleging the algorithm's denials were reversed on appeal more than ninety percent of the time. The company kept using it.

Notice what these systems have in common. They wait for a claim, then refuse care a patient already needs. Backward-looking, every one of them, a machine for saying no to what has already gone wrong. And that is only the crude version of the idea. It is already this destructive.

The trajectory enables the version GINA was actually written to prevent. Not denying the claim you filed. Flagging you before you file anything, before you are sick, before you have any idea anything is wrong, pricing a future the law walled off when it was written in your genes and left wide open when it is written in your data, using a prediction that is often better than your genes precisely because it reflects how your body is actually changing rather than how it was born.

Here is the honest objection. Genes are fixed and a trajectory is not. The whole point of reading a trajectory forward is that someone can act on it and change the ending. A drifting kidney caught early can be saved. That is a reason to read trajectories, not to fear them. Wall them off and you lose the lives early detection saves.

That is true, and it is exactly why this is hard. Genetic information was easy to protect because it was mostly useless to the patient and dangerous in the wrong hands. A trajectory is enormously useful to the patient and dangerous in the wrong hands. You cannot ban it. You would be banning early medicine.

Which means the question was never whether to read the trajectory. It is who is allowed to, and on whose behalf. The same question GINA answered for genes, now with higher stakes, because you cannot settle it by forbidding the data. The data has to be read. The only decision left is who reads it, and who they answer to.

The lines are being redrawn, slowly. In 2024 California passed SB 1120, which says a health insurer cannot use an algorithm as the sole basis to deny care. A licensed clinician has to make the call. It is a real law and a good one. It is also aimed at the reactive problem, the claim already filed, the nH Predict scenario. It says nothing about the prospective one. It does not touch who gets to read your trajectory before you are ever sick.

We wrote GINA in 2008 for a technology, genetic testing, that turned out to predict less than we feared. We have not written anything for the technology that predicts more.

And it is not obvious what that law would even say. That is the part that resists a tidy ending. You cannot wall off a trajectory the way you walled off a gene, because the reading is the thing that saves the patient. A rule strong enough to keep the prediction from an insurer is strong enough to keep it from a doctor. Protect people from the forecast and you protect them from the cure. Nobody has drafted the version that threads that needle, and it is possible nobody can.

We built Chroneme to read trajectories, so we do not get to pretend the question belongs to someone else. Our answer is that the trajectory belongs to the clinician and the patient, that the reasoning behind every read is something a doctor can open and check, and that a prediction about where your health is going should answer to you and no one standing behind you. That is a choice we made, not a property of the technology. Anyone building this makes the same choice, whether they admit it or not.

The genome got a law. The trajectory has not. It predicts the same future, it sits in the same gap, and right now the only thing deciding who it serves is whoever chooses where the signal goes.