Acute intermittent porphyria
Are there one or two characteristic odd or unusual symptoms or clinical features of acute intermittent porphyria?
Some people having an attack of acute intermittent porphyria may have reddish-brown or red urine (especially if the urine is exposed to air and light). Even if the urine is not discolored, all people having an attack of acute intermittent porphyria will have high levels of porphobilinogen (PBG) in their urine (often 10 to 20 times higher than normal). Your doctor can test for this if you think you are having an attack.
Acute Intermittent Porphyria. Gene Reviews. (http://www.ncbi.nlm.nih.gov/books/NBK1193/)