Doctors examined my daughter and her husband for spots like my grandson has. They did not have any. The nerve part of the disease consists of tumors on the nerves called neurofibromas, benign tumors arising from the cells that make up the sheathes around nerves. They rarely can be malignant. It is often impossible to predict the degree of difficulty someone who has inherited the condition will have as they grow and mature.
Some people never have more than a couple of cafe au lait spots.
Others have spots plus neurofibromas in the skin that look like small, flesh-colored lumps under the skin surface. Some have severe and disabling disease when the neurofibromas occur in constricted areas like the spinal canal or the small holes where nerves exit the spine. Tumors in these locations, although benign, can nonetheless have severe consequences due to pressure on the nerves interfering with nerve function. Depending on the nerve, this can produce weakness, paralysis, or loss of sensation. The variability of the disease is truly amazing.