A. Tuberous sclerosis is a complex genetic disorder (a disease that occurs due to some defect in the genes) that is characterized by skin lesions, nervous system affectation and renal involvement primarily. The name is derived from tuber - like growths on the brain that become hard. These tubers are seen as white areas on a CT Scan of the brain. These abnormal growths can affect any organ of the body (even the eyes, kidneys, heart and the lungs).

EVERY INDIVIDUAL WITH TUBEROUS SCLEROSIS IS AFFECTED DIFFERENTLY. SOME INDIVIDUALS ARE TOTALLY UNAFFECTED WHEREAS SOME PEOPLE ARE MORE SEVERELY AFFECTED.

Q: How common is tuberous sclerosis?

A. Out of every 6000 newborns, one may have tuberous sclerosis. More than 1 million people around the world are known to have tuberous sclerosis. These may still be many undiagnosed cases and mild forms of the disease.

Q. How does a person with tuberous sclerosis present?

A. The disease spectrum of tuberous sclerosis is very diverse. Some may present with a very severe form whereas some may be totally unaffected.

Tuberous sclerosis primarily affects the brain, skin, eyes, kidneys, heart and bones.

Brain -

Due to growth of tuber like structures, these patients may have fits (convulsions), mental retardation, behavioural problems and learning disability. Infants may develop a peculiar kind of fit called salaam fits (infantile spasms). These fits appear as if they are bowing down in a salute. As the child grows the fits may change or sometimes just stop all together.

Learning disabilities are also Quite common. By the age of 2 years, it is Quite clear whether a child with tuberous sclerosis will have developmental problems or not.

Tubers may block the flow of the brain fluid (CSF) causing retention of fluid in the brain (hydrocephalus). It may present as headache, vomiting, walking problems and worsening of fits.

Skin -

The earliest sign to develop would be white skin patches (ash- leaf patches) especially on the limbs and the trunk. They cause no problems and disappear later in life. As the child grows older, a characteristic facial rash known as adenoma sebaceum (facial angiofibroma) develops across the nose and the cheeks. At first, the rash starts as pinpoint spots which later form small bumps. Later in life, small nodules of skin form around the fingers or toe nails (periungal fibroma). Shagreen patches appear on the lower back as raised patches of skin with an orange-peel texture.

Kidneys -

Kidney disorders are seen in 40 - 80 percent of patients with Tuberous sclerosis. They usually cause problems in the 2^nd and 3^rd decade of life. Tumours of the kidney ( angiomyolipoma ) and cysts are the most common lesions seen. These may cause bleeding from the kidney either into the urine, around the kidney or in the abdomen. There may be abdominal pain , fever, anemia ( low haemoglobin ) and general illness. Kidney failure is rare. Hence, regular monitoring of kidney problems with kidney ultrasound ( 1 to 3 yearly), urine and blood tests with blood pressure monitoring is necessary. Polycystic kidney disease may also be seen. It causes high blood pressure and deteriorating kidney function. There are so many cysts that compress the normal kidney and ultimately deteriorate renal functions. Hence regular monitoring is required.

Heart -

There are benign rare growths in the heart known as rhabdomyomas. They tend to progressively grow smaller and disappear after the first year of life. A child with tuberous sclerosis may develop heart failure, which may present itself as shortness of breath, fainting spells (not due to fits) and swelling of ankles.

Eyes -

It causes growth in the retina of the eye called retinal hamartoma or phakoma.

Q: Why does tuberous sclerosis occur?

A. Tuberous sclerosis is a genetic disorder (due to errors in the genes). Children have a 50% chance of inheriting tuberous sclerosis if one of the parents have this condition. However 2/3^rd of the cases are due to spontaneous genetic errors, the cause of which is still a mystery.