A genotype that is not uniformly expressed as a phenotype.
the situation in which an allele that is expected to be expressed is not always expressed.
The gene for a condition is present, but not obviously expressed, in all individuals with the gene in a family.
A trait “should” appear but doesn't. For example, polydactyly is a dominant trait but not everyone with one gene for polydatyly has an extra toe or finger. Don't confuse with incomplete dominance where the heterozygote has an intermediate phenotype between the two possible homozygotes.
A genotype that does not always produce a phenotype. 275
Occurs when a gene only sometimes results in disease.
The situation in which an allele is expressed only if certain factors are present in the environment. The triggering of genetically inherited diabetes by obesity is an example.
Absence of expression of the phenotype in an obligate gene carrier.
A dominant gene that is not always expressed.