Ataxia with oculomotor apraxia (AOA) is a group of autosomal recessive cerebellar ataxias mainly characterized by ataxia, oculomotor apraxia and choreoathetosis. AOA includes ataxia telangiectasia (AT), ataxia telangiectasia like disorder (ATLD), ataxia oculomotor apraxia type 1 (AOA1) and ataxia oculomotor apraxia type 2 (AOA2). AT, ATLD, and AOA1 are due to homozygous mutations in genes encoding a protein involved in DNA repair. Ophthalmic features of AT include conjunctival telangiectasia, strabismus, saccadic dysfunction with head thrusts, and convergence insufficiency. AOA1 is typically characterized by early-onset cerebellar ataxia, oculomotor apraxia, hypoalbuminemia, hypercholesterolemia and late axonal sensori-motor neuropathy. The gene mutated in AOA2, SETX, encodes senataxin, a putative DNA/RNA helicase which has been shown to play a role in the response to oxidative stress.
