Ataxia-telangiectasia (A-T) is a rare, inherited disorder that affects multiple systems in the body, leading to a wide range of complications. These complications arise because A-T impacts the nervous system, immune system, and other organs, causing progressive disability and increased vulnerability to infections and cancer.
One of the primary complications of A-T is **progressive neurological decline**. The hallmark symptom is ataxia, which means loss of muscle coordination. This usually begins in early childhood with unsteady, jerky walking and difficulty with fine motor tasks. Over time, the ataxia worsens, leading to severe problems with balance, walking, and coordination of the hands and eyes. Children with A-T often develop abnormal eye movements (oculomotor apraxia), speech difficulties, and muscle weakness. Eventually, many become wheelchair-bound due to the progressive loss of motor control. The neurological deterioration is relentless and significantly impacts quality of life.
Another major complication is **telangiectasia**, which are small, dilated blood vessels visible on the skin and eyes. These usually appear by age 5 to 8, especially on the white part of the eyes and sun-exposed areas like the face and ears. While telangiectasia itself is mostly a cosmetic issue and does not cause bleeding or itching, it is a visible marker of the disease and can sometimes be mistaken for other conditions like chronic conjunctivitis.
The **immune system dysfunction** in A-T is profound and affects about two-thirds of patients. Many have low levels of immunoglobulins (antibodies) and reduced numbers of lymphocytes, especially T cells, which are crucial for fighting infections. This immune deficiency leads to frequent and severe infections, particularly in the respiratory tract, such as repeated colds, sinus infections, ear infections, bronchitis, and pneumonia. Because of this, infections are a major cause of illness and can be life-threatening. Some patients require immunoglobulin replacement therapy, prophylactic antibiotics, and special vaccinations to help prevent infections.
People with A-T also have a significantly increased risk of developing **cancers**, especially lymphomas and leukemias. This is related to the underlying genetic defect affecting DNA repair mechanisms, which leads to genomic instability and higher cancer susceptibility. The risk of cancer increases with age, and cancer is a leading cause of death in individuals with A-T.
**Pulmonary complications** are common and serious. Chronic lung disease can develop due to repeated infections, impaired clearance of secretions, and weakened respiratory muscles. This can lead to bronchiectasis (permanent airway damage), respiratory failure, and increased risk of pneumonia. Swallowing difficulties caused by neurological decline can cause aspiration of food or liquids into the lungs, further worsening lung health.
Feeding and nutritional problems also arise as the disease progresses. Difficulty swallowing (dysphagia) can lead to choking, aspiration, and malnutrition. Maintaining adequate nutrition becomes a challenge, and some patients may require feeding tubes to ensure proper intake.
Other complications include **skin changes** such as the telangiectasia mentioned earlier and increased sensitivity to sunlight. Eye problems beyond telangiectasia, like abnormal eye movements and difficulty focusing, contribute to visual impairment.
Autonomic nervous system dysfunction may also occur, causing issues like abnormal heart rate, blood pressure instability, and problems with sweating and temperature regulation. Spasticity (muscle stiffness) and muscle weakness can further impair mobility.
In summary, the complications of ataxia-telangiectasia are wide-ranging and affect many body systems. The progressive neurological decline leads to severe motor disability. Immune deficiency causes recurrent infections and increases cancer risk. Pulmonary disease, feeding difficulties, and skin and eye abnormalities add to the disease burden. These complications require careful, multidisciplinary management to improve quality of life and address the complex needs of individuals with A-T.
