What are polygenic disorders?

What are polygenic disorders?

• A. Disorders caused by a single gene mutation
• B. Disorders that are caused by multiple genes and environmental factors
• C. Disorders that require no genetic influence
• D. Disorders that affect only one family member

Answer: (B)

Polygenic disorders are characterized by the involvement of multiple genes, each contributing a small effect to the overall phenotype, and they are also influenced by environmental factors. This complexity arises from the interplay between genetic predispositions and external conditions, which can affect the expression of these disorders. For instance, conditions such as diabetes, hypertension, and many common mental health disorders exemplify polygenic traits. In these cases, no single gene dictates the disorder; rather, it is the cumulative effect of variations in several genes, along with lifestyle and environmental factors, that ultimately lead to the development of the condition. Other options do not accurately describe polygenic disorders. A single gene mutation refers to monogenic disorders, which are caused by alterations in a single gene. Disorders requiring no genetic influence do not align with the definition of genetic and genomic conditions, as polygenic disorders inherently involve genetic factors. Finally, suggesting that polygenic disorders only affect one family member overlooks the heritable nature of many such conditions, which often manifest in multiple individuals within a family due to shared genetic risks.

Polygenic disorders are characterized by the involvement of multiple genes, each contributing a small effect to the overall phenotype, and they are also influenced by environmental factors. This complexity arises from the interplay between genetic predispositions and external conditions, which can affect the expression of these disorders.

For instance, conditions such as diabetes, hypertension, and many common mental health disorders exemplify polygenic traits. In these cases, no single gene dictates the disorder; rather, it is the cumulative effect of variations in several genes, along with lifestyle and environmental factors, that ultimately lead to the development of the condition.

Other options do not accurately describe polygenic disorders. A single gene mutation refers to monogenic disorders, which are caused by alterations in a single gene. Disorders requiring no genetic influence do not align with the definition of genetic and genomic conditions, as polygenic disorders inherently involve genetic factors. Finally, suggesting that polygenic disorders only affect one family member overlooks the heritable nature of many such conditions, which often manifest in multiple individuals within a family due to shared genetic risks.