Phakomatoses

Abstract

The major phakomatoses that present with developmental problems are neurofibromatosis type 1 (NF1) and tuberous sclerosis complex (TSC). Both are autosomal dominant disorders with complete penetrance, variable expression, and a high rate of new mutation. Diagnosis of each disorder is established using clinical criteria, and genetic testing is available for both conditions. NF1 is usually diagnosed on the basis of multiple café-au-lait spots, skin fold freckling, and eventually the development of neurofibromas. Learning disabilities, attention deficit disorder, and other neurocognitive problems occur commonly. Tuberous sclerosis complex affects the skin, brain, kidneys, lungs, and other tissues. The most important central nervous system manifestations are seizures, developmental problems, and in some cases progression of subependymal giant cell astrocytoma. Both NF1 and TSC are important to recognize, as they may first be diagnosed in the context of a developmental evaluation, and both present with longstanding neurocognitive problems that require ongoing management.