The
genotype is that part (
DNA sequence) of the
genetic makeup of a
cell, and therefore of an organism or individual, which determines a specific characteristic (
phenotype) of that cell/organism/individual. Genotype is one of three factors that determine phenotype, the other two being inherited
epigenetic factors, and non-inherited environmental factors.
DNA mutations which are acquired rather than inherited, such as cancer mutations, are not part of the individual's genotype; hence, scientists and
physicians sometimes talk for example about the (geno)type of a particular
cancer, that is the genotype of the disease as distinct from the diseased.