Neurofibromatosis 1

NF1 is a disorder that causes the growth of neurofibromatous tumors that can compress nerves and cause nerve damage, pain, and loss of function. 

Though it is often autosomal dominant (inherited from one parent), it can also be a new mutation which happens randomly. 

Other symptoms include nodular and soft tumors of the skin, café-au-lait (brownish) spots on the skin, impaired cognitive function, leg fractures, underarm or groin freckles, convulsions, and blindness.  There is currently no cure.  Complications may include tumors that become malignant (cancerous).  Treatment includes possible surgical removal of individual tumors.