Just when you think you can't learn anything from the royal baby coverage, you uncover a rare metabolic disorder in the baby's namesake. Learn why porphyria can drive you mad, and make your urine blue.


There's a new King George on the horizon, and while listening to coverage of it, I learned a little something about a previous King George. I'd heard one of them went mad, but I didn't know that he famously peed blue. A little digging and I found out that both are symptoms of the same condition - porphyria.

Porphyria stems from a genetic mutation that makes the body underproduce the enzyme porphobilinogen deaminase. This enzyme is critical for hemoglobin production. The process of making heme - the pigment in red blood cells - starts out in the mitochondria, but takes a trip around the outer cell before being completed and delivered back to the mitochondria. The lack of the enzyme leaves the uncompleted heme in the cell. Heme is part of a group of molecules called porphyrins, and while it doesn't get back to the mitochondria, the production process doesn't stop. The heme, or phorphyrin, builds up in the body.


After some time, the heme starts interfering with a lot of functions. The most common symptom of porphyria is abdominal pain, but if it starts causing problems in the brain it brings on extreme restlessness, hallucinations, and delirium. The porphyrin is finally excreted in the urine. Since heme is a pigment, it stains the urine. Usually the urine is tinged red or purple, but there are cases in which the urine turned blue, or left behind blue stains.

The famous King George III, who ruled during the American revolution and was said to undergo bouts of madness, has been posthumously diagnosed as having acute intermittent porphyria. The attacks came and went, but some people believe that his disease was worsened by his doctors. The medicine they gave him was contaminated with arsenic, which can bring on attacks of porphyria - as well as other unpleasant symptoms.

Via American Scientist, MHHE, NCBI.