Tuberous sclerosis, also known as tuberous sclerosis complex or TSC, is a genetic disease wherein non-malignant tumors develop on vital organs, including the brain, heart, kidneys, lungs and skin, explains the National Institute of Neurological Disorders and Stroke. The disorder is caused by flaws in two genes: TSC1 and TSC2.
Tuberous sclerosis primarily affects the central nervous system and may manifest as developmental delays, intellectual disabilities, behavioral problems, seizures and autism, states Tuberous Sclerosis Alliance. Cardiac rhabdomyoma, an anomalous growth in the cardiac muscle, is another characteristic manifestation of the disorder. Other features of tuberous sclerosis include kidney diseases and skin abnormalities. Because tuberous sclerosis manifests in many different ways, it can go unrecognized for years.
As an autosomal dominant disorder, tuberous sclerosis can be directly inherited from a parent. Individuals with tuberous sclerosis have a 50 percent chance of passing the disorder to their offspring. However, most cases of tuberous sclerosis result from spontaneous mutations in TSC1 or TSC2, explains Tuberous Sclerosis Alliance.
As of February 2015, 25,000 to 40,000 individuals in the United States are diagnosed with tuberous sclerosis. It affects 1 to 2 million individuals around the world, states the National Institute of Neurological Disorders and Stroke. Approximately one in 6,000 babies is born with the disorder.