A report of a joint meeting of the Forum on Mental Retardation of the Royal Society of Medicine and The Tuberous Sclerosis Association of Great Britain states that the prevalence of tuberous sclerosis (TS) for children under 15 years may be 1 in 10,300. Evidence for the assignment of the TS gene to chromosome 9 was reviewed, and high levels of carbohydrate specific to a glycoprotein-fibronectin in the affected skin of TS patients noted. Infantile spasms associated with TS may have a better prognosis than in non-TS patients. Cognitive deterioration in TS is usually related to underlying pathology rather than seizure frequency or severity. Of 88 children with TS followed until the age of 5 years, 81% of those who were walking showed severe psychiatric disorder, 59% were autistic, and 70% had hyperkinetic behavior disorders. Infantile spasms were associated with autism in 68%, 79% were severely mentally handicapped, and 47% were in special care units of schools. The detection of rhabdomyomata by echocardiography was a valuable diagnostic technique, positive in 47% of 60 children and adults with TS. A greater awareness and early diagnosis of TS is called for. [1]

COMMENT. Forehead plaques, smooth patches of slightly raised skin with a reddish or yellowish discoloration, can be one of the earliest skin manifestations of TS. Wood's light examination of the skin for hypopigmented maculae is important in all infants with myoclonic spasms and hypsarrhythmia. (see Ped Neur Briefs 1987;1:3). MRI may help in predicting the eventual clinical severity of younger children with newly diagnosed TS, whereas the number of CT brain abnormalities does not correlate with prognosis. High-signal MRI lesions involving the cerebral cortex are characteristic of TS and correspond to hamartomas and gliotic areas seen pathologically. Periventricular calcific lesions are better visualized with CT than with MRI. [2]