Phenotypic Variance
Definition
Phenotypic variance is the observed variability of a particular trait. For many measurable traits (such as height, skin color, and blood pressure) phenotypic variation can be thought of as a distribution. The variation within that distribution centers on an average or mean. Phenotypic variance is often caused by a combination of genetic and environmental factors.
Narration
So phenotypic variants can be seen in a disease eye study known as mitochondrial disease within a single family where the same pathogenic variant may be shared, for example, between siblings. Additional genetic and environmental factors can contribute to two phenotypic differences between these individuals.
