A single nucleotide variants (SNV) describe genetic alterations occurring in a single nucleotide (adenine [A], thymine [T], cytosine [C], or guanine [G]). When a SVP occurs in more than 1% of a population it is known as a single nucleotide polymorphism (SNP). Oncology panels that screen for SNVs in a patient's tumor to aid in optimizing personalized treatment options.