Ataxia-telangiectasia

Ataxia-telangiectasia is a rare, progressive inherited disorder whose name describes its two hallmark features: ataxia, a loss of coordinated movement, and telangiectasia, small clusters of dilated blood vessels visible on the skin and in the eyes. It is caused by mutations in the ATM gene and inherited in an autosomal recessive pattern, requiring a non-working copy from each parent; the ATM gene normally produces a protein that helps cells detect and repair broken DNA, so its loss leaves cells vulnerable to accumulating genetic damage. Symptoms usually begin in early childhood with worsening balance and coordination problems and difficulty controlling eye movements, followed over time by the characteristic dilated blood vessels, frequent infections caused by a weakened immune system, and speech and swallowing difficulties. Because DNA repair is impaired throughout the body, affected individuals also face a substantially elevated lifetime cancer risk, estimated at around one in four. Diagnosis combines these clinical features with laboratory findings including elevated alpha-fetoprotein, reduced antibody levels, chromosomal instability on testing, and abnormal sensitivity of cells to radiation exposure. No treatment cures the underlying DNA repair defect; care is supportive, using antibiotics for recurrent infections, physical therapy to help preserve mobility, nutritional support, and accommodations for learning, while experimental therapies such as N-acetyl-leucine are being studied.