Affecting the nervous system, immune system and other body organs, ataxia telangiectasia is characterized with uncoordinated movements of the individual suffering from this disorder. The secondary tell tale sign is the enlarged blood vessels visible under the surface of the skin like tiny red spider webs. They are predominantly visible inside the eye giving a red appearance to the whites of the eye.
The condition affects 1 in 40,000 to 100,000 people in the world and is considered a rare disease. The other names of ataxia telangiectasia include Louis-Bar syndrome, ataxia telangiectasia mutated (ATM), cerebello-oculocuaneous, and AT.
Causes of Ataxia Telangiectasia
Ataxia telangiectasia is a genetic disorder and is passed down from both parents to the child. Since it is an autosomal recessive trait both father and mother need to have the mutant gene in order to pass on the genetic disorder to the child. Boys and girls are equally susceptible to developing the condition. The ATM gene is responsible for triggering the disorder.
For two carrier parents, it is 25% likely to give birth to a child affected with the condition. There is a 50% chance that two carrier parents will have a child who is also a carrier and will not develop ataxia telangiectasia. A 25% chance exists that two carrier parents pass on normal genes to the child and there is no risk of the disease.
Signs of the disease can be seen in early infancy between the ages of one and three years. If there is a family history of the disease, parents should be alert to the possible symptoms. Having ataxia telangiectasia also puts the child at a 37 times higher risk for developing cancer. There is a 10% risk of developing leukemia or lymphoma if diagnosed with ataxia telangiectasia.
Signs of Ataxia Telangiectasia to Watch for in Children
Ataxia or progressive difficulty in coordinating movements is usually the first sign of ataxia telangiectasia. Children develop this involuntary and jerky movement by the age of five. They may also suffer from muscle twitching. They could have difficulty in balance and hand coordination. They may find it problematic to move eyes from side to side. Their speech could get slurred.
Telangiectasias or the tiny spider veins begin to appear at the eye corners, on the ears, and cheeks a bit later. The eye vessels look bloodshot and it may spread to other areas of the body. This sign may not be present in the initial years at all. Children with the condition may have difficulty swallowing. They also suffer from premature grey hair and delayed physical development. They have an increased susceptibility to infection and often fall sick with respiratory system related illnesses.
Tests and Diagnosis of Ataxia Telangiectasia
Clinical evaluation is the basis for diagnosis of ataxia telangiectasia. The uncoordinated neck and head movement, jerky walking, as well as decreased deep tendon reflexes are considered during the medical investigation. These symptoms are studied in conjunction with a detailed history of the patient and family to provide the initial diagnosis. The healthcare practitioner may also observe skin color and texture changes.
This will be followed by specialized tests such as MRI to create cross-sectional images of the brain to check for cerebellar atrophy. Blood tests are performed to look for alpha fetoprotien, of which elevated levels are seen in nearly 85% individuals suffering from ataxia telangiectasia. Genetic testing for the ATM gene may be undertaken, and karyotyping may be done to detect chromosomal abnormalities.
Glucose tolerance test may also be done. Serum immunoglobulin levels of IgE and IgA may be checked. It is difficult to diagnose the condition in very young children. However, as mental development slows down progressively and may stop completely by age 10, it becomes simpler to identify ataxia telangiectasia.
Treatment Options for Ataxia Telangiectasia
There is no cure for this genetic disease. The treatments are symptom specific. As it is an immune system related disorder, the child is likely to develop repeated infections due to the weakened immune system. These need to be treated as they occur. Here are some treatment options that may be exercised.
- Generally speaking, the patient should avoid extra exposure to sunlight so that the dilated blood vessels do not spread too much.
- Diazepam or Valium may be prescribed to help slurred speech and muscle contractions that are involuntary in nature.
- Vitamin E therapy can provide temporary relief for some symptoms present in ataxia telangiectasia.
- Physiotherapy for muscles can aid in relieving the painful limb contractions, as it helps to strengthen the muscles.
- Some patients may develop mild case of diabetes mellitus, and so glucose levels need to be closely monitored to check for insulin levels.
- There is an increased risk of cancers of the stomach, brain, ovary, liver, larynx, parotid gland, skin, and breast for which treatment will be specialized.
- Flu vaccinations are a good way to avoid repeated respiratory infections.
Reviewed by Susha Cheriyedath, MSc