Why has the dominant mutant allele for Huntington's disease been able to persist in human populations despite its devastating effects?

A) It has a heterozygote advantage.
B) Its symptoms do not typically show until after the individual has had children.
C) Its effects are not expressed in heterozygous individuals.
D) Its effects are only expressed in homozygous recessive individuals.
E) Its effects are only expressed in homozygous dominant individuals.

Huntington's Disease

A genetic disorder characterized by the progressive breakdown of nerve cells in the brain, leading to deterioration of physical and mental abilities.

Dominant Mutant Allele

A variant of a gene that is more potent in expressing its trait even in the presence of its normal counterpart.

Heterozygote Advantage

A phenomenon in which the heterozygous condition confers some special advantage on an individual that either homozygous condition does not (i.e., Aa has a higher degree of fitness than does AA or aa).