Ataxia-Telangiectasia (A-T) is a rare genetic disorder that affects the nervous system and immune system. It is caused by mutations in the ATM gene, which plays a crucial role in repairing DNA damage. Individuals with A-T often experience progressive loss of coordination and balance, known as ataxia, along with the development of small dilated blood vessels, or telangiectasia, particularly on the face and eyes. People with A-T may also have an increased risk of infections and certain cancers due to immune system deficiencies. Symptoms typically appear in early childhood, and while there is no cure, supportive treatments can help manage the condition and improve quality of life.