Getting Wolfy...

Werewolves are shape shifters with rare strength, swiftness, and senses. We have all seen werewolves portrayed in movies and TV shows like Twilight, Underworld, and even the Vampire Diaries, but do werewolves really exist?

In early Greece it was alleged that a person could be changed into a werewolf through consuming the meat of a wolf that had been combined with the meat of a human, which was thought to be a disease that was permanent. In the next centuries, people thought you could become a werewolf in a variety of ways including:  slumbering under a full moon on a Friday, via a curse, being produced under a full moon, by ingesting various herbs, or even consuming water that a wolf had been in contact with. It was also accepted that wolves dressed in a protective wolf skin, which was detached during the day and concealed. If the magical skin was stolen, he or she could be slain.

There are two medical conditions that could explain lycanthropy. One is clinical lycanthropy, where a person believes that he or she is a werewolf. An example can be seen in 1589, where Peter Stubbe alleged to own a wolf skin belt that allowed his transformation into a werewolf. He alleged that he killed at least 12 people over a time span of 25 years, some of which were consumed, and he was burned at the stake during Halloween in 1859. It is thought that he was mentally ill.
The other condition is hypertrichosis, which is a disease where there is excessive growth in body hair in excess of the ordinary quantity when compared to persons of equal age, race, or sex. People have been recorded to bare this disease since the middle Ages, and were often exhibits in fairs and circuses due to their phenotype. Hypertrichosis can be congenital or acquired. Congenital is rare, and is possibly an isolated skin ailment or factor of an alternate disease. Acquired hypertrichosis is more common and may be due to drug side effects, metabolic ailments, malnourishment, anorexia, and even ovarian neoplasms. Other signs of hypertrichosis include: facial disfigurement, irregularities of the eyes, heart, bones and kidneys.
It is thought that hypertrichosis might be due to a excess stimulus of hair follicles with ordinary levels of androgen-like hormones. Another hypothesis is that the physical features are caused by a relapse of a suppressed familial gene. In idiopathic hypertrichosis, some of the patterns of inheritances have been thought to be due an autosomal dominant trait with two plus family members affected or an X-linked type of inheritance. The connection of chromosome 8 has been reported in individuals with congenital hypertrichosis, and in those particular cases males were more ailed than females. However, the actual epidemiology is uncertain.
Therefore, it is my belief that since this disease has been around for long time that this possibly could be the origin of werewolf lore. I also am curious as to whether an individual has been reported with both porphyria and hypertrichosis (a hybrid), and if the relation of the genes involved if they were in conjunction with one another.
http://eds.a.ebscohost.com/eds/pdfviewer/pdfviewer?vid=3&sid=e5ffc643-d94d-42ab-8926-1f6857d64ee3%40sessionmgr4001&hid=4203
http://www.livescience.com/24412-werewolves.html