linear rash?

My mother recently explained to me that I was born with  a rare and deadly cancer called linear rash. A strange rash going up my left leg in large clumps on my foot, leg, and thigh. Doctors didnt know much about it back then but they told my mother that I woundnt make it to age 15, if I so much as bumped myself I'd be compleatly paralized, and one morning I'd wake up with no memories like an infent.

I'm 19-years-old now and made it through the worst of it. I'd like to know more about it. Anything.