Viraj's Weblog

Another good quote from Genetic Rounds:

It was not because I'm a brilliant diagnostician or because I'm a sensitive listener that I happened to make the diagnosis of acute intermittent porphyria in Nicole and her mother (a diagnosis that was ultimately confirmed through the demonstration of a deficiency of the enzyme uroporphyrinogen I synthase in the girl's red blood cells). Had I seen this family one year before, I'm sure I would have failed, just like the dozen other specialists who had seen Nicole in the past. No, in the case of Nicole Ludlow, I was able to come up with the correct diagnosis simply through dumb luck: the Ludlows and I had managed to run into each other in exactly the right place at exactly the right time.

Dumb luck is an important factor in the lives of clinical geneticists. Dumb luck and hunches, and a little bit of knowledge of weird rare facts, are pretty much all that keep me in business.

The author gives a harrowing story about an infant born with a debilitating disease, to its possible association with vampires:

... After repeated exposure to light, people with CEP [congenital erythropoietic porphyria] become more and more disfigured: their skin becomes covered with scars, and some areas on their scalp lack hair whereas some areas on their skin sprout hair indiscrimately.

Interestingly, it is the presence of these clinical features that has led some medical historians to speculate that individuals with CEP served as the origin of the legend of the vampire, an ancient myth that is present in a large number of diverse cultures. Vampires are portrayed as deceased individuals who find themselves rejected by the hallowed earth of cemeteries because they have been cursed in some way. Unable to achieve a state of peace in their own graves, they metamorphosize into the undead or the living dead, trapped between the worlds of the living and the dead. Hideously ugly and constantly in need of sustenance, vampires are destined to walk the earth after dark, looking to feed on the blood of the innocent.

Now consider individuals with CEP. Because the porphyrins in their bloodstream result in photosensitivity, these people's faces are scarred. And because of the photosensitivity, coupled with their psychological sensitivity, they learn early in life to leave their homes only at night. Finally, because of the deposition of the abnormal red porphyrins in the structure of their teeth, people with CEP develop erythrodontia (literally, "red teeth"), giving the uninformed the impression that they have been drinking blood. It's not difficult to understand how, in an age when superstition and ignorance ruled, the birth of an infant with CEP might have led to the beginning of a tale of the undead that ultimately grew into today's legend.

He goes on:

It's never difficult to figure out when Edwin has been admitted to the hospital: he's the one in the room in which the shades have been drawn, the lights have been turned out, and the light switch has been taped into the off position. In his hospital crib, Edwin lies behind an orange Plexiglas sheet that blocks out most of the wavelengths of light that would prove most harmful to his skin. Because of the careful precautions taken by his parents, Edwin's skin is not terribly scarred at this point. But how can a child live like this? How can he grow and develop, make friends, go to school, and live in society with a condition that allows him to exist outside his home only in the dark?

However, the postscript to this story has a happy ending. Through a bone marrow transplant this boy was eventually cured.