[Ataxia Telangiectasia].

Ocular telangiectasias are pathognomonic of ataxia telangiectasia (AT), and they usually appear after 6 years of age. Skin and visceral telangiectasias may appear with advancing age. They may represent a progeric change. When present, ocular telangiectasias facilitate the clinical diagnosis of AT, but they are minimally present or absent in milder variants.