Question

Genetic anticipation is associated with:

A More mutated mitochondria being passed from the mother in later generations
B An increased age of onset in later generations
C Toxic metabolites being passed to the fetus in an affected mother
D Trinucleotide repeat instability
E Threshold of expression of mutations

Answer 1

Genetic anticipation is associated with trinucleotide repeat instability, where the lengths of these repeats in the DNA can increase with subsequent generations, leading to earlier and more severe manifestation of genetic disorders.

Step-by-step explanation:

Genetic anticipation is associated with trinucleotide repeat instability. This biological phenomenon involves the lengthening of trinucleotide repeats in the DNA, which can cause a gene to malfunction. As a result, in subsequent generations, there can be an earlier onset and more severe manifestation of genetic disorders. Examples of diseases displaying genetic anticipation due to trinucleotide repeat expansions include Huntington's disease and certain forms of muscular dystrophy.

Environmental factors and lifestyle choices can influence the epigenome, thereby affecting gene expression. However, this is distinct from genetic anticipation, which specifically refers to a progressive pattern whereby symptoms worsen with each generation.

Concerns over how our own behaviors—such as smoking or diet—might have epigenetic implications for our descendants underscore the intricate relationship between our genome, epigenome, and the environment. The field of epigenetics provides insight into how changes beyond the DNA sequence can impact gene expression and can be heritable.