Tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant
disorder with a birth incidence of about 1 in 6000. TSC is very
variable in its clinical presentation. The classical triad of mental
retardation, epilepsy and adenosum sebaceum are present in
only 30% of cases. TSC is characterised by hamartomas in
multiple organ systems, commonly the skin, CNS, kidneys,
heart and eyes. The ectodermal manifestations of the condition
are shown in the table. CNS manifestations include cortical
tumours that are associated with epilepsy and mental
retardation, and subependymal nodules that are found in 95%
of subjects on MRI brain scans. Subependymal giant cell
astrocytomas develop in about 6% of affected individuals. TSC
is associated with both infantile spasms and epilepsy occurring
later in childhood. Learning disability is frequently associated.
Attention deficit hyperactivity disorder is associated with TSC
and severe retardation occurs in about 40% of cases. Renal
angiomyolipomas or renal cysts are usually bilateral and
multiple, but mainly asymptomatic. Their frequency increases
with age. Angiomyolipomas may cause abdominal pain, with or
without haematuria, and multiple cysts can lead to renal failure.
There may be a small increase in the risk of renal carcinoma in
TSC. Cardiac rhabdomyomas are detected by echocardiography
in 50% of children with TSC. These can cause outflow tract
obstruction or arrhythmias, but tend to resolve with age.
Ophthalmic features of TSC include retinal hamartomas,
which are usually asymptomatic.