Dr.Greene, I am a retired Family Practitioner. My 7-week-old grandson has 7 cafe-au-lait spots. What does this mean about his chances of developing neurofibromatosis?

Both Joseph (John) Merrick, the Elephant Man, and Quasimodo, the Hunchback of Notre Dame, are dramatic examples that have shaped our perceptions of neurofibromatosis. NF, also known as von Recklinghausen disease, is one of humankind's most common neurological genetic disorders, indeed it is one of the most common genetic disorders of any kind.

"Treat me as an equal!" cried Merrick, whose appearance caused him to be ridiculed and rejected by 19th-century England. This courageous, intelligent, sensitive poet could find employment only as a sideshow freak.

Merrick's mother was once watching a parade when, in the crush of spectators, she was pushed under an Elephant's feet, "which frightened her very much," wrote Merrick. "This occurring during a time of pregnancy was the cause of my deformity."

Some doctors didn't agree.

Merrick was brought before the Pathological Society of London by Sir Frederick Treves. A diagnosis of NF was finally made in 1909. So firm was this diagnosis that NF came to be called "Elephant Man's disease." The photograph of Merrick's notorious disfigurement became the indelible image of NF in the minds of those familiar with it.

Not until the 1980’s did we learn that Merrick didn't have NF but an unrelated condition called proteus syndrome (British Medical Journal, 1986; 293:683--685). I didn't know this in 1982 when I read Merrick's poignant three-page autobiography -- after my surgeon told me he thought I might have NF.

Neurofibromatosis is a genetic disorder of the nervous system that causes benign tumors to form on the nerves anywhere in the body at any time. At least eight varieties of NF exist and can range from very mild to quite severe (Clinical Pediatric Dermatology, WB Saunders,1993), but fortunately none are as disfiguring as the tragic case of the Elephant Man.

Café-au-lait spots are a classic feature of this disease. These flat birthmarks with distinct edges are a bit darker than the surrounding skin. In light-skinned individuals, they are the color of coffee with lots of cream. In those with darker skin, they can be the color of a rich, full-bodied, black coffee. The spots can increase in size, number, and darkness throughout childhood.

Having one to three café-au-lait spots is quite common, present in as many as one in five healthy children. Each spot of significant size after the first three, though, is increasingly uncommon and increasingly likely to be associated with NF or with one of the other neurocutaneous syndromes, including neurofibromatosis type 2, segmental neurofibromatosis, tuberous sclerosis, McCune Albright syndrome, Fanconi anemia, Bloom syndrome and ataxia telangiectasia (CMAJ, Aug 2002; 167:3.).

Neurofibromatosis is diagnosed not with a test but by the presence of certain physical findings.