A few years ago a patient has weird labs. His ferritin is high and his red blood cell count is high. Polycythemia, where he has too many red blood cells. If the count gets too high, it increases the risk of heart attack, stroke, blood clots or sudden death, because the cells sludge. The cells are small, as they would be with iron deficiency, but the ferritin indicates he has lots of iron.

I send him to Dr. N., our hematologist-oncologist. The patient is unenthusiastic, but agrees to go.

He returns some months later. "I have a JAK2 mutation." he says.

"Hmmm. Never heard of it." I say.

"It's new. He put me on iron and hydroxyurea." he says. Both are cheap. "I feel better than I have in 30 years. Thank you!"

I read about JAK2 mutations. One of the fun things about my job is that new things turn up all the time. I go to conferences and I do more than my required fifty hours of continuing medical education a year, but I cannot read every single paper in every single specialty. One of my family medicine talents is noticing when something is off and knowing who to call.

By now I have three people diagnosed with JAK2 mutations. They all have presented in different ways, but all with weird lab results. I send another patient with thrombocythemia, a high platelet count, but she doesn't have a JAK2 mutation. She has another genetic disorder: an even newer one.


Iron Noder: Tokyo Drift 3