History of the tuberous sclerosis complex.

How the concept of the tuberous sclerosis complex (TSC) has developed over a period of time spanning 160 years has come form simple clinical observations, pathological studies and technological advances of imaging methods. It all began with PFO Rayer's color plate of a drawing of a patient who apparently had facial angiofibroma, published in the year 1835, and continued with von Recklinghausen's report of cardiac myomas and cerebral sclerosis in a newborn who had died minutes after birth. The seminal contribution was provided by D.M. Bourneville who, in 1880, reported and named as tuberous sclerosis the neuropathological findings in a young patient with seizures, hemiplegia, and mental subnormality who also had renal tumors. We now know that TSC is a hamartomatosis, and thanks to studies of recent years using positional cloning and DNA analysis, we are beginning to understand the biological mechanisms of these disorders which include NF1, NF2 and von Hippel-Lindau disease. Unique to TSC is that it is both phenotypically and genotypically heterogeneous. One of two suspected genes found in chromosome 16 by positional cloning has been cloned (TSC2). Another one that was discovered earlier in chromosome 9 (TSC1) has not yet been characterized. The gene product from TSC2 has been named tuberin.