Tuberous sclerosis complex is a genetic disorder, usually diagnosed in childhood or infancy, that affects multiple body systems. Symptoms and progression vary drastically from one case to another, causing a lot of uncertainty when it comes to prognosis and care. Tuberous sclerosis is somewhat rare, affecting about one in 6,000 to 10,000 people.
Tuberous sclerosis is caused by a defect on two different genes, but only one of the genes has to be affected for someone to have the disease.Each defect affects the production of a protein that acts as a growth inhibitor. Without the ability to slow or stop growth, abnormal cell development occurs. About a third of people with this disease inherit the defective gene from a parent.
The severity of tuberous sclerosis is highly variable. Symptoms can differ greatly in severity even between a parent and child who both have the condition. These variations largely depend on what parts of the body are affected.Some people have such a mild form of the disease that it goes undiagnosed well into adulthood, while others will experience severe complications early in life.
Benign tumors are one of the hallmark symptoms of tuberous sclerosis. As their name implies, they are rarely cancerous. When they are, they usually affect the kidneys.Multiple types of brain lesions may occur, as well as tumors in the eyes, lungs, liver, pancreas, and bones. Cardiac tumors often appear in young children and infants with the disease. While these tumors may block circulation and cause sudden cardiac death in younger children, in the majority of instances, they do not grow with age and can shrink over time, having little effect as the children age.
Most people with tuberous sclerosis have skin abnormalities. Infants may have white patches on the legs, arms, and trunk at birth. Between 3 and 5, children may develop red spots and small bumps that grow and spread until adolescence. Some people develop thick flesh-colored patches on the lower back or plaques on the forehead, cheeks, or scalp.
People with tuberous sclerosis have seizures at some point, varying from convulsions to altered awareness to absence seizures where they stare into space and blink rapidly.Roughly half of the people with this condition have developmental delays ranging from mild to severe. Many have behavioral problems, including rage, aggression, OCD, ADHD, and self-harm.
Kidney problems are also common in tuberous sclerosis, most commonly cysts. These affect more than 70 percent of people with this condition and usually appear between ages 15 and 30. Most growths are small and do not cause any serious problems, though if they appear in childhood, they can lead to kidney failure.Benign tumors called angiomyolipomas are the most common kidney lesion in this disease, and while they do not produce any symptoms initially, they may grow large enough to cause kidney failure.
In more severe cases, symptoms of tuberous sclerosis, like tumors in the heart and brain, may begin before birth and be picked up on ultrasound.Developmental delays, intellectual disabilities, and seizures usually appear in childhood. In adulthood, renal and pulmonary symptoms are most common, including the formation of unusual clumps of cells in the kidney or lungs.
When symptoms appear in childhood, diagnosis usually involves multiple specialists, including neurologists, dermatologists, and kidney specialists. Exams will focus on looking for benign tumors and blood and genetic testing.MRI, CT, and ultrasounds identify tumors in the brain, lungs, and kidneys. Doctors may perform an EKG and echocardiogram to see whether there are tumors in the heart and if they are affecting heart function.
There is no cure for tuberous sclerosis, but treatment can help manage symptoms. Doctors often prescribe medication to control seizures and manage heart arrhythmias and behavioral or mood problems. If growths are affecting organ function, surgeons may remove them.For children, early intervention and speech, occupational, and physical therapy can help them manage daily tasks and have a high quality of life. Mental health care is also an important part of managing tuberous sclerosis, as children often need help adjusting to living with this disorder.
Prognosis and Management
Tuberous sclerosis has a highly variable clinical course. Prognosis is uncertain, but an early diagnosis and management can help people with the disease cope with the symptoms. Many symptoms take years to develop, and regular follow-ups and testing can help identify problems early and prevent complications.