A type of mutation that involves a change in a single nucleotide is referred to as a point mutation. These mutations can result in the substitution of one base pair for another, which may lead to changes in the amino acid sequence of a protein. Point mutations can be classified into three categories: sickle cell mutation (missense), premature stop codon (nonsense), and silent mutation (no change in the amino acid sequence). The consequences of point mutations can vary, ranging from benign to severely detrimental effects on an organism.