Ataxia Telangiectasia (ATM), known as the master regulator of DNA double-stranded break (DSB) response, surprisingly results in mild immunodeficiency in ataxia telangiectasia patients, unlike other DSB repair syndromes. This explores ATM’s roles in DSB repair, cell cycle control, and their impact on adaptive immunity. Despite its diverse functions, ATM isn’t an absolute necessity for acquiring sufficient immunological diversity to prevent severe infections. However, ataxia telangiectasia exhibits a clinically significant antibody deficiency due to disrupted class switch recombination.
