Gene mutation refers to a permanent alteration in the DNA sequence of a gene. These changes can occur spontaneously or be induced by external factors such as exposure to radiation, chemicals, or viruses. Mutations can have varying impacts on an organism, ranging from no effect to causing genetic diseases or predisposing individuals to certain conditions such as cancer. Understanding gene mutations is important in research as it can help identify genetic causes of diseases, develop targeted therapies, and improve breeding practices in agriculture.