Saturday, February 17, 2007

Giant Dork Alert!

Title: the Family That Couldn’t Sleep: A Medical Mystery
Author: D.T. Max

So back in college, my all-time favorite course was Epidemiology and the Evolution of Disease, which, of course, had absolutely nothing to do with my major. I’m apparently a medical anthropologist at heart. :-) And I wrote this big paper on Transmissible Spongiform Encephalopathy, which is the generic term for the class of diseases like Mad Cow disease (which is actually Bovine Spongiform Encephalophathy) – the name derives from the way the brains of the subjects look – full of holes, like a sponge. Unfortunately, it’s very difficult to diagnose a living creature – the most reliable test is to look at the brain after death for characteristic structures.

The disease itself is caused by a protein known as a prion. Not a virus, or bacteria – just a simple, non-living building block. Proteins within the body fold into characteristic shapes; prions have the chemical structure of their normal protein counterparts, but fold into the wrong shape. The disease spreads within the body by the mal-formed protein causing normal proteins to re-fold into the prion shape. It’s kindof like when you have a super-saturated solution of sugar water. It stays liquid, unless you drop in a regular sugar crystal, or a string – and then all the sugar within the water starts to clump onto the one different piece, and you get rock candy.

But back to prions. They can’t be killed, since they’re not alive, and they’re practically impossible to destroy – irradiation, formaldehyde, etc., are pretty much useless.

There’s actually several different classes of prion diseases – some are spontaneous – like Creutzfeld-Jacob disease. Some are passed down genetically, like Fatal Familial Insomnia (the inspiration for the book’s title). And some are passed subject to subject like a normal infectious disease, like kuru, scrapie, and Mad Cow, though you have to have contact with the prions themselves, which is why this is more challenging - but still do-able, often through consumption of brain tissue.

Some of these diseases have been around for centuries; because there’s nothing that can really be tested for, the victims were often diagnosed as dying from other diseases. It wasn’t until the mid-twentieth century that they really started to make some progress in the field. Even now, there’s a few different camps and bitter rivalries between some of the leading researchers, plus the requisite conspiracy theorists.

The book focuses on a family in Italy that suffers from FFI; the most tragic part of the story is that it doesn’t set in until the person is around 50 years old. That is, they don’t know if they’re a carrier until after they’re likely to have had children, and potentially passed it on to them. The disease progresses over the course of a few months - they just can’t sleep, and the body shuts down. There’s no explanation, and no cure, and it’s painful to watch. It’s been passed through their family for hundreds of years, almost always diagnosed as something else.

There’s also detailed descriptions of one researcher in New Guinea, studying kuru, a similar disease that affects a native tribe. Plus the history of scrapie, a prion disease that struck mainly Great Britain’s sheep population, but poor control of transmission may have started the Mad Cow epidemic.

It’s an incredibly detailed and interesting book. And somewhat terrifying to have reinforced how little we know about this class of diseases – and how governments are so often more concerned about image than control. (I’ll be avoiding ground beef for a while now, I think…).
If you’re looking for something out of the ordinary, I highly recommend finding and reading this one.

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posted by ket at 1:59 PM