Until modern methods of clinical and scientific research were applied to neurofibromatosis (NF) over the last 30 years, the disease was largely regarded as a medical curiosity. In 1987, a NIH consensus conference agreed a disease classification system and diagnostic criteria for the two main forms. They are defined by the presence/absence of specific nervous system tumours (neurofibromas in NF1, schwannomas in NF2), skin pigmentation, and ophthalmological features. The recognition of the different types is not just an academic exercise (and one geneticists are fond of!), because the natural history and management of each type is distinct.
One important feature in both forms of neurofibromatosis, and indeed in other phakomatoses like tuberous sclerosis, is that the different disease features develop at different ages. For example in NF1, the café-au-lait spots develop during the first two years of life but dermal neurofibromas are unusual before the late teens or early twenties. Despite developments in molecular diagnosis it is probably still more cost effective to refer unusual patients to a specialist clinic prior to testing.
