one of the things that we discuss is the use of a u.v. meter this is a u.v. meter and plays with the u.v. meter works is that there is a photo electric cell here at the top of the meter and all you do is shine out photo electric cell at a light source for example the sunlight coming through this window. as you can see that u.v. meter is registering numbers and for many patients this. level of u.v. is too much and will be causing damage. and if we step into the full sun we'll see that. registering in the thousands this amount of u.v. is enough to cause significant amounts of damage to people with x.p. for even a short amount of time being outside. no more like a few seconds. one two three four we . know you. well i. experience a genetic disease in the united states and europe expiate is about one in a million in other parts of the world it's much more common for instance in japan it's one in twenty thousand and we did some studies that show most of the patients with x p plan have the same patient of the same great community. and we call that a fountain mutation