Ataxia Telangiectasia

**Definition:** An autosomal recessive inherited disorder characterized by choreoathetosis beginning in childhood, progressive CEREBELLAR ATAXIA; TELANGIECTASIS of CONJUNCTIVA and SKIN; DYSARTHRIA; B- and T-cell immunodeficiency, and RADIOSENSITIVITY to IONIZING RADIATION. Affected individuals are prone to recurrent sinobronchopulmonary infections, lymphoreticular neoplasms, and other malignancies. Serum ALPHA-FETOPROTEINS are usually elevated. (Menkes, Textbook of Child Neurology, 5th ed, p688) The gene for this disorder (ATM) encodes a cell cycle checkpoint protein kinase and has been mapped to chromosome 11 (11q22-q23).

**Tree numbers:** - C10.228.140.252.190.530.060 - C10.562.100 - C10.597.350.090.500.530.060 - C14.907.823.213 - C16.320.080 - C16.320.798.250 - C18.452.284.060 - C20.673.795.250

**Synonyms:** - Ataxia-Telangiectasia - Louis-Bar Syndrome - Ataxia Telangiectasia Syndrome - Telangiectasia, Cerebello-Oculocutaneous