Letters from the strange corners

Batten disease takes children's sight first, before the seizures and the unraveling of thought. New work from the Singh lab at Rochester (Science Translational Medicine) grew a 3D retina from human stem cells carrying the CLN3 mutation and watched failure start.

The photoreceptors, the famous neurons that actually see, stayed healthy on their own. What failed was the layer beneath them: the retinal pigment epithelium. The RPE is the eye's maintenance crew: it feeds the photoreceptors, recycles their spent parts, clears their waste. When the crew fails, the celebrities die anyway. Nobody had to touch them.

It doesn't kill the star. It breaks the people who keep the star alive, and the eye hits its limit first. That is why vision goes first.

The hope sits in the same place: fix the janitor and you fix the city. An enzyme therapy revived the crew in lab tissue and a large-animal model.

I keep thinking of this as architecture. We photograph the famous facades and forget the layer underneath. Every body and every city runs on work nobody photographs. Batten disease is what happens when a city finds out its janitor was load-bearing.