Tuberous sclerosis complex (TSC) causes amongst many symptoms those of some learning disabilities. TSC is sometimes genetic and one of the signs of it is tumors in organs such as the brain, heart, eyes, lungs and skin. They are not cancerous. It generally affects the central nervous system. About 1 in 6,000 babies are born with the disease.

Some people have mild cases and others severe with a wide range in the middle. Since this is a learning disabilities site, in this article I'll be talking about developmental problems, ADHD, retardation and its relation to autism. But, again, not everyone has so many outward symptoms and in fact there may never be a diagnosis. It is thought to be as common as ALS, which would be at least a million people on the planet.

If it is known that a parent has TSC, genetic testing is in order because kids have a 1 in 2 chance of inheriting it if at least one of their parents has the complex. But, what is interesting is that only about 1 in 3 cases are actually inherited, the rest are born with a spontaneous gene mutation in TSC1 or TSC2, meaning the individual is the first affected rather than inherited.(1)

Whereas 3% to 5% of kids in the general population have ADHD, as many as 25% to 50% of children with TSC exhibit signs of Attention Deficit Hyperactivity Disorder. Some signs of ADHD are constantly moving around, trouble completing tasks, inattention, being disorganized, amongst others.(2)

It is thought that 40% of people with TSC are mentally retarded. The number used to be thought higher, but this is the current research. This is based on a child at least 8 years old who has an IQ of at least 70. The more tubers a person has in their brain, the more retarded they are likely to be.(3)

Current research shows that between 25% and 50% of children with TSC also develop one of the autism spectrum disorders. It is believed that the brain tubers interfere with development of social communication skills. Furthermore it appears that spasms or epilepsy in youngsters with cortical brain tubers is a combination that leads to autism.(4)

Many people with TSC are so mildly affected that they are never diagnosed. Treatment consists of controlling the symptoms. Currently research is being carried out mostly by the United States Federal Government at the National Institute of Neurological Disorders and Stroke (NINDS).(1)

References:
(1) Tuberous Sclerosis Fact Sheet
http://www.ninds.nih.gov/disorders/tuberous_sclerosis/detail_tuberous_sclerosis.htm
(2) ADHD and TSC
http://tsalliance.easycgi.com/Fact%20Sheets/ADHDnTSC.pdf
(3) Mental Retardation in TSC
http://tsalliance.easycgi.com/Fact%20Sheets/mentalretardation.pdf
(4) TS and Autism Spectrum Disorders
http://tsalliance.easycgi.com/Fact%20Sheets/TS%20and%20autism%20spectrum%20disorders.pdf