Gene variants are differences in the DNA sequence among individuals. These variations can occur in a single nucleotide, which is the basic building block of DNA, or in larger segments of genes. Some gene variants are harmless, while others can influence traits or increase the risk of certain diseases. The study of gene variants is important in fields like genetics and medicine. Understanding these differences helps researchers identify how they contribute to hereditary conditions and can guide personalized treatment options. By analyzing gene variants, scientists can better understand human diversity and the biological basis of various health conditions.