What is the Difference Between Polygenic Inheritance and Pleiotropy?

The main difference between polygenic inheritance and pleiotropy lies in the number of genes involved in controlling a trait and the number of traits affected by a single gene, respectively.

Polygenic Inheritance:

Involves multiple genes contributing to a single trait.
One trait is controlled by multiple genes.
Traits often form a phenotypic spectrum rather than falling into clear-cut categories.
Many genes work together to make a specific characteristic, such as height, skin pigmentation, or hair color.

Pleiotropy:

Occurs when one gene affects multiple traits.
A single gene has many phenotypic consequences.
One gene can have an effect on a certain characteristic and another separate characteristic, such as Marfan syndrome, where a single gene mutation can lead to heart defects and a tall, thin build.
Examples include albinism, phenylketonuria, autism, sickle cell anemia, and Marfan syndrome.

In summary, polygenic inheritance involves multiple genes contributing to a single trait, while pleiotropy involves a single gene affecting multiple traits.

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What is the Difference Between Polygenic Inheritance and Pleiotropy?

Comparative Table: Polygenic Inheritance vs Pleiotropy

Here is a table comparing the differences between polygenic inheritance and pleiotropy:

Feature	Polygenic Inheritance	Pleiotropy
Definition	Polygenic inheritance refers to the control of a single phenotypic trait by multiple genes. Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits.
Gene-Trait Relationship	In polygenic inheritance, multiple genes contribute to a single trait. In pleiotropy, one gene affects multiple unrelated traits.
Phenotypic Spectrum	Polygenic inheritance often results in a phenotypic spectrum, where traits form a continuous range rather than clear-cut categories. Pleiotropy, on the other hand, can result in discrete phenotypes influenced by a single gene.
Environmental Influences	Environmental factors can significantly impact traits in polygenic inheritance. Environmental influences are usually less significant in pleiotropy.
Examples	Height, skin color, eye color, and weight in humans are examples of polygenic inheritance. Albinism, phenylketonuria, autism, sickle cell anemia, and Marfan syndrome are examples of pleiotropy.

In summary, polygenic inheritance involves multiple genes contributing to a single phenotypic trait, while pleiotropy involves a single gene influencing multiple unrelated phenotypic traits.

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.