Ataxia Telangiectasia

Ataxia means walking with an unsteady gait caused by the failure of muscular coordination or irregularity of muscular action. There are many forms of ataxia. Some taxis are hereditary, some have other causes and sometimes ataxia can be a symptom of other disorders. To locate information about other types of ataxia choose “ataxia” as your search term on the Rare Disease Database.

Symptoms of the following disorders can be similar to ataxia-telangiectasia. Comparisons may be useful for a differential diagnosis:

Friedreich’s ataxia is a genetic, progressive, neurologic movement disorder that typically becomes apparent before adolescence. Initial symptoms may include unsteady posture, frequent falling, and progressive difficulties walking due to an impaired ability to coordinate voluntary movements (ataxia). Affected individuals may also develop abnormalities of certain reflexes; characteristic foot deformities; increasing incoordination of the arms and hands; slurred speech (dysarthria); and rapid, involuntary eye movements (nystagmus). Friedreich’s ataxia may also be associated with cardiomyopathy, a disease of cardiac muscle that may be characterized by shortness of breath upon exertion (dyspnea), chest pain, and irregularities in heart rhythm (cardiac arrhythmias). Some affected individuals may also develop diabetes mellitus, a condition in which there is insufficient secretion of the hormone insulin. Primary symptoms may include abnormally increased thirst and urination (polydipsia and polyuria), weight loss, lack of appetite, fatigue, and blurred vision. Friedreich’s ataxia may be inherited as an autosomal recessive trait. (For more information on this disorder, choose “Friedreich’s ataxia” as your search term in the Rare Disease Database.)

Marie’s ataxia is a neuromuscular syndrome inherited as a dominant trait. Also known as Pierre Marie’s disease or hereditary cerebellar ataxia, it often begins during the third or fourth decade. An early symptom is an unsteadiness walking downstairs or on uneven ground. Frequent falls may occur as the disorder progresses as well as tremors, loss of coordination in the arms, and speech disturbances. In later stages, slight loss of vision, and loss of pain or touch sensations, may also occur. Swallowing and clearing of secretions may eventually become difficult if the throat muscles are affected. (For more information on this disorder, choose “Marie” as your search term in the Rare Disease Database.)

Charcot Marie Tooth hereditary neuropathies are a group of disorders in which the motor and sensory peripheral nerves are affected, resulting in muscle weakness and atrophy, primarily in the legs and sometimes in the hands. CMT hereditary neuropathy affects the nerves that control many muscles in the body. The nerve cells in individuals with this disorder are not able to send electrical signals properly because of abnormalities in the nerve axon or abnormalities in the insulation (myelin) around the axon. Specific gene mutations are responsible for the abnormal function of the peripheral nerves. Charcot Marie Tooth hereditary neuropathy can be inherited in an autosomal dominant, autosomal recessive, or X-linked mode of inheritance. (For more information on this disorder, choose “CMT” as your search term in the Rare Disease Database.)

Hereditary olivopontocerebellar atrophy (OPCA) is a rare group of disorders characterized by progressive balance problems (disequilibrium), progressive impairment of the ability to coordinate voluntary movements (cerebellar ataxia), and difficulty speaking or slurred speech (dysarthria). There are at least five distinct forms of hereditary OPCA. All forms of hereditary OPCA, except one, are inherited as autosomal dominant traits. The term olivopontocerebellar atrophy has generated significant controversy and confusion in the medical literature because of its association with two distinct groups of disorders, specifically multiple system atrophy (MSA) and spinocerebellar ataxia (SCA). OPCA may refer to a specific form of MSA or one of several types of SCA. Hereditary OPCA refers to the group of disorders that overlaps with SCA. Both forms of OPCA are characterized by progressive degeneration of certain structures of the brain, especially the cerebellum, pons, and inferior olives. The cerebellum is the part of the brain that plays a role in maintaining balance and posture as well as coordinating voluntary movement. The pons is part of the brainstem and contains important neuronal pathways between the cerebrum, spinal cord, and cerebellum. The pons serves as a relay point for messages between these structures. The inferior olives are two round structures that contain nuclei that are involved with balance, coordination, and motor activity. (For more information on this disorder, choose “hereditary olivopontocerebellar atrophy” as your search term in the Rare Disease Database.)