Question

Huntington's disease is inherited in humans as an autosomal dominant gene. Affected individuals show progressive brain deterioration from cell death in the cerebral cortex. Onset of the disease usually occurs between ages 30 and 50. Give two possible reasons for the observed variation in the age of onset of this disease.

Answer 1

The observed variation in the age of onset of Huntington's disease can be attributed to genetic variability and environmental factors.

Step-by-step explanation:

Huntington's disease is an autosomal dominant disorder characterized by progressive brain deterioration, typically becoming symptomatic between the ages of 30 and 50. Two possible reasons for the variation in age of onset include genetic variability and environmental factors. Genetic variability means that different mutations or the number of CAG repeats in the Huntington gene can affect onset age, as some mutations might lead to an earlier or later onset. Environmental factors encompass a range of lifestyle influences and other genetic modifiers that could potentially influence when symptoms start to appear.