Question

A 24-year-old woman with myotonic dystrophy, a genetic disorder caused by a dominant mutant allele, has significant muscle weakness and wasting. She has a 1- year-old son with very poor muscle tone, severe weakness, and significant developmental delay. Her affected 55-year-old father has minor cataracts but no muscle weakness. Which of the following terms BEST describes this situation?

a. compound heterozygote
b. multiple alleles
c. complementation
d. codominance
e. anticipation

Answer 1

The term that BEST describes the situation is anticipation, where the severity of a genetic disorder increases in successive generations. This is observed in the 1-year-old son of the woman with myotonic dystrophy, who has more severe symptoms and developmental delay.

Step-by-step explanation:

The BEST term to describe this situation is anticipation. Anticipation refers to a genetic phenomenon where the severity or age of onset of a genetic disorder increases in successive generations.

In this case, the 1-year-old son of the woman with myotonic dystrophy has more severe symptoms and developmental delay compared to his mother. This is an example of anticipation, where the symptoms of the disorder worsen in subsequent generations.

This phenomenon is commonly observed in genetic disorders caused by trinucleotide repeat expansions, such as myotonic dystrophy.