The Role Of Mitochondrial Diseases In Children
Mitochondrial Diseases are very diverse. Specialized organelles in every cell of the body (only red blood cells lack mitochondria). Mitochondria generate more than 90% of the energy required by the body. Mitochondrial dysfunction depletes cells of energy causing cell damage and even cell death. Due to the high energy requirements of brain and muscle, mitochondrial disease typically affect these parts of the body causing Brain and Muscle disease. Other organs are frequently affected including: eye, ears, heart, liver, gastrointestinal tract, liver, kidney, endocrine system, and blood.
The diseases predominantly affect children, but adult-onset disorders are being recognized with increasing frequency. Mitochondria are unique organelles because
they are the products of their own genetic material and nuclear DNA. Therefore, mitochondrial diseases are caused by mutations in either mtDNA or nuclear DNA. Mitochondrial diseases are often difficult to diagnose and therefore, it is important for patients to be evaluated at a medical center with appropriate expertise.
Physical examination and laboratory tests are necessary to characterize involvement of various organs and to reach the correct diagnosis. Laboratory studies typically include: blood tests, brain MRI or CT scans, heart tests, ophthalmological and neurological evaluations.
Finally, genetic testing of blood, urine, or muscle is performed to pinpoint the exact mutation responsible for a specific disease. Treatment of mitochondrial diseases is limited. Therapies to treat specific symptoms and signs of mitochondrial diseases are very important. For example, in mitochondrial patients, epilepsy typically responds to anti-convulsant drugs while insulin and other standard treatments are effective for diabetes mellitus.
Retinitis pigmentosa is an inherited mitochondrial condition that involves both eyes. If it starts in one eye,it usually moves to the next eye. There are about 75,000 people in the United States with retinitis pigmentosa (RP). Since retinitis pigmentosa begins as rod degeneration, the patient first notices increasing difficulty in night vision, followed by difficulty seeing in the periphery. Slowly progressive constriction of the visual field leads to tunnel vision. A small area of central vision in both eyes usually persists for years. Generally night blindness precedes tunnel vision by years or even decades. Total blindness eventually ensues in most cases.
For years, vitamin A therapy has been recommended for many RP patients, based on research dating back to the early 1990s., it has been the only treatment found that slows the RP process.
The diseases predominantly affect children, but adult-onset disorders are being recognized with increasing frequency. Mitochondria are unique organelles because
they are the products of their own genetic material and nuclear DNA. Therefore, mitochondrial diseases are caused by mutations in either mtDNA or nuclear DNA. Mitochondrial diseases are often difficult to diagnose and therefore, it is important for patients to be evaluated at a medical center with appropriate expertise.
Physical examination and laboratory tests are necessary to characterize involvement of various organs and to reach the correct diagnosis. Laboratory studies typically include: blood tests, brain MRI or CT scans, heart tests, ophthalmological and neurological evaluations.
Finally, genetic testing of blood, urine, or muscle is performed to pinpoint the exact mutation responsible for a specific disease. Treatment of mitochondrial diseases is limited. Therapies to treat specific symptoms and signs of mitochondrial diseases are very important. For example, in mitochondrial patients, epilepsy typically responds to anti-convulsant drugs while insulin and other standard treatments are effective for diabetes mellitus.
Retinitis pigmentosa is an inherited mitochondrial condition that involves both eyes. If it starts in one eye,it usually moves to the next eye. There are about 75,000 people in the United States with retinitis pigmentosa (RP). Since retinitis pigmentosa begins as rod degeneration, the patient first notices increasing difficulty in night vision, followed by difficulty seeing in the periphery. Slowly progressive constriction of the visual field leads to tunnel vision. A small area of central vision in both eyes usually persists for years. Generally night blindness precedes tunnel vision by years or even decades. Total blindness eventually ensues in most cases.
For years, vitamin A therapy has been recommended for many RP patients, based on research dating back to the early 1990s., it has been the only treatment found that slows the RP process.