TUBEROUS SCLEROSIS

Familial Hamartomas

Tuberous Sclerosis is a genetic condition that causes hamartomas (a kind of benign tumor) to appear all over the body -- usually in the brain and skin, but also the kidneys, lungs and eyes. 

Which genes are mutated?

TSC1 or TSC2. TSC1 encodes for hamartin, while TSC2 encodes for tuberin. Hamarin and tuberin work together as tumor suppressors. Without that hamartin-tuberin action, the cell cycle is disrupted all over the body, and benign growths pop up all over the place. Rather than a single cell type, TS tumors are made up of multiple different cell types, called hamartomas. As expected, the lifetime risk of cancer is increased. 

What are the symptoms?

Well it depends where the tumors pop up. In the brain, they tend to form along the outside of the cortex (seizures, intellectual disability) and underneath the ependyma (subependymal astrocytomas). On the skin, they tend to form on the face (angiofibromas) and under the nails. Tumors can grow in the heart (rhabdomyomas) and kidneys (angiomyolipoma). 

Here are the tell-tale skin symptoms. 

• Ash leaf spots are pale and flat discolorations

• Shagreen patches are large, elevated, skin-colored, fibrous (“shag-gy”-looking) blobs on the lower back. I couldn't find a license-free picture unfortuanately.