“When you hear hoofbeats, think of horses not zebras”

It’s a quote by a professor at the University of Maryland School of Medicine in the 1940s. A reminder to his students that, when searching for a diagnosis, not to think of the obscure until you can rule out the likeliest possibilities. I will never forget hearing it for the first time when a pile of medical students came into Jack’s room at Columbia Presbyterian Morgan Stanleys Children’s Hospital ten years ago. One of the students tapped the young man next to him and whispered, “Dude – THIS is a zebra!”

If Jack is a zebra, then Jon is a unicorn, with purple and cyan stripes. I met him this fall at an ALD event and I kept finding myself staring at him across the table. He’s in his mid-twenties, has his degree from the Milwaukee School of Engineering, is a…