Phenylketonuria (PKU) is an autosomal recessive disease that results from a defect in an enzyme that normally metabolizes the amino acid phenylalanine; when this enzyme is defective, high levels of phenylalanine cause brain damage. In the past, most children with PKU became intellectually disabled. Fortunately, intellectual disability can be prevented in these children by carefully controlling the amount of phenylalanine in the diet. The diet is usually applied during childhood, when brain development is taking place. As a result of this treatment, many people with PKU now reach reproductive age. Children born to women with PKU (who are no longer on a phenylalanine-restricted diet) frequently have low birth weight, developmental abnormalities, and intellectual disabilities. However, children of men with PKU do not have these problems. a. Provide an explanation for these observations. b. What type of genetic effect is this? Explain your reasoning.
Phenylketonuria (PKU) is an autosomal recessive disease that results
from a defect in an enzyme that normally
phenylalanine; when this enzyme is defective, high levels of
phenylalanine cause brain damage. In the past, most children with
PKU became intellectually disabled. Fortunately, intellectual disability
can be prevented in these children by carefully controlling the amount
of phenylalanine in the diet. The diet is usually applied during
childhood, when brain development is taking place. As a result of this
treatment, many people with PKU now reach reproductive age.
Children born to women with PKU (who are no longer on a
phenylalanine-restricted diet) frequently have low birth weight,
developmental abnormalities, and intellectual disabilities. However,
children of men with PKU do not have these problems.
a. Provide an explanation for these observations.
b. What type of genetic effect is this? Explain your reasoning.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
