Cockayne syndrome is a rare inherited disorder in which defective DNA repair causes profound growth failure, premature ageing, sensitivity to sunlight, and progressive neurological decline. Children grow very slowly, develop characteristic facial features, and lose hearing, vision, and cognitive function over time. There is no cure; care is supportive, with feeding difficulties often requiring dietetic input to maintain growth and nutrition despite swallowing problems and poor appetite. Sun protection is essential. The condition illustrates the devastating consequences when cells cannot repair everyday DNA damage, and nutritional support aims to maximise quality of life within severe limits.