Editor—Tuberous sclerosis complex (TSC) is a dominantly inherited disease of high penetrance, characterised pathologically by the presence of hamartomata in multiple organ systems. Well known clinical manifestations include epilepsy, learning difficulties, behavioural problems, and skin lesions. Many patients have renal lesions, usually angiomyolipomata (AML), which can cause clinical problems secondary to haemorrhage or by compression and replacement of healthy renal tissue, which rarely causes end stage renal failure.1 Cysts, polycystic renal disease, and renal carcinoma can also occur. Polycystic disease has an early onset clinically and is the result of large contiguous deletions on chromosome 16 affecting both the TSC2 gene and the gene for adult onset polycystic kidney disease.2Tuberous sclerosis complex exhibits genetic heterogeneity.3 Mutations in two recently identified genes, TSC1 at 9q34 andTSC2 at 16p13, each result in an apparently similar phenotype, although recent work has suggested that mutations inTSC2 may be associated with more severe …