Ataxia Telangiectasia or Louis-Bar Syndrome Ataxia Telangiectasia (A-T) is an inherited syndrome of progressive cerebellar ataxia which begins in infancy, involving a progression of symptoms including incoordination of limbs, head and eyes, eye and skin telangiectasia (dilated blood vessels), susceptibility to sinus and lung infections and a tendency to neoplasia (growth of tumors). The age of onset is usually infancy or early childhood. The disorder becomes apparent when the child begins to walk. SYMPTOMS Early signs of A-T are: - Lack of coordination in walking - Cerebellar ataxia (incoordination) of the head and body - Tremor when moving the upper extremities The ataxia may be quite steadily progressive. In the early stages, before the appearance of telangiectasia, ataxia telangiectasia may be misdiagnosed as ataxic cerebral palsy or even Friedreich ataxia. CAUSES A-T is a systemic genetic disorder with multi-system manifestations. Immunological deficiency (lack of normal immune responses to infections) is one manifestations of A-T; however, there is no evidence that all patients have immunological abnormalities. The basic etiology of the disease is still unknown. Symptoms of the disorder are caused by diffuse changes in the central nervous system, mainly in the cerebellum, but also involving the spinal cord and peripheral nerves and muscles. The main immunological defect is due to the thymus gland deficiency and may result in two main causes of death for those with A-T: pulmonary (lung) infection and neoplasia. PATTERN OF DEVELOPMENT A-T appears to be transmitted as an autosomal recessive trait. This means, the disorder would only appear if a child receives the A-T gene from both parents, which can occur among several siblings in a family. The parents are called carriers and would not be affected. It is unlikely that an A-T patient's children would have A-T, unless the spouse also had A-T or was a carrier. FREQUENCY OF A-T Anyone, male or female, can be equally afflicted with A-T. Cases have been reported in all races and from many regions all over the world. From reports of cases in certain areas of the United States, the prevalence has been observed to be 1.5 cases per 100,000 population. Clinical Manifestations of A-T - Progressive cerebellar ataxia beginning in infancy. - Progressive telangiectasia, beginning in the eyes as a "bloodshot" appearance and spreading to the eyelids, butterfly area of the face, external ears, roof of the mouth, and possible other areas. - Occasional nosebleeds may also result. - Susceptibility to sinopulmonary infections and chronic lung infections, recurrent pneumonia and chronic bronchitis. These chronic infections do not respond well to antibiotic therapy and may lead to respiratory insufficiency and death. - Increasing incoordination of swallowing and breathing, causing drooling, choking and diminished cough reflexes. - Equable, appreciative and generally undemanding disposition, helping the patient to adjust to the progressive disability. - Characteristic dull and sad facial expressions and characteristic postural attitudes. - Peculiar eye movements which start slowly and often involve blinking, turning of the head and nystagmus (rapid eye movements). - Slow, dysarthic (slurring) speech. General muscle weakness with muscle atrophy and fasciculations (muscle contractions). - Variable jerking, writhing and tie-like movements and occasional myoclonic (muscle contracting) jerks. - High incidence among siblings. - Absence of mental deterioration initially--mental deficiency may appear as the disease progresses. - Retardation of growth resulting in below normal height and weight, possibly due to a growth hormone deficiency. - Premature aging of hair and skin, causing much graying of hair in adolescence, dry and atrophic skin with changes in pigmentation and an appearance of premature (aging) again. - Endocrine abnormalities with hypogonadism, sexual infantilism and absence or incomplete development of the ovaries in females. - Poor development or absence-of adenoids, tonsils and abnormal peripheral lymph node structure. - High incidence of carcinoma and lymphoma with frequent onset in young adulthood. - Individuals with one A-T gene (carriers) also appear to have an elevated risk for cancer. Progression of A-T The rate of progression and severity of the disease varies from one patient to another. Symptoms progress slowly and relentlessly. Usually by the age of 10 to 11 the patient requires a wheelchair due to the incoordination of walking, fatigue and frequent falling. Death may occur in adolescence or early adult life, due to lung infection (pneumonia), cancer of the lymph glands or both. However, if these are not contracted, some patients have lived into their early forties. Treatment of A-T No treatment has been found, as yet, to stop the progression of A-T. All therapy is directed toward the treatment of symptoms or conditions as they manifest in the course of the disorder. These measures may include: - For respiratory infections, therapy with an antibiotic, postural drainage, and gamma globin injections in some cases. - Avoidance of undue exposure to sunlight on the telangiectasia. - Vitamin E therapy, in some cases, has provided temporary improvement. - Diazapam (valium) has been useful in some cases of slow speech and involuntary movements. - Physical therapy to help maintain muscle strength and prevent limb contractures. - For a positive outlook and to ward off infection, it is important that good general, physical and mental health be maintained. Research of A-T Research studies are under way in the areas of immunology and endocrinology, to develop laboratory procedures for earlier diagnosis and specific therapy. The defect of the insulin receptor which causes insulin-resistant diabetes is also being studied. In addition, research is being done on viruses in tumor and brain tissue. These, especially the immunology studies, appear to hold promising discoveries. However, much more research will need to be done before a treatment or cure for A-T can be realized.