Explain how intellectual disability may result from PKU. What ...

[crobinson2013]

Explain how intellectual disability may result from PKU.
 
  What will be an ideal response?

Question 2

Discuss two conditions that can arise from chromosomal abnormalities.
 
  What will be an ideal response?

[nikmaaacs]

Answer to Question 1

One of the best understood examples of a single gene condition is phenylketonuria (PKU), a rare disorder occurring in approximately 1 in 15,000 individuals (Waisbren, 2011). Unlike chromosomal abnormalities that cause Down syndrome, the cause of PKU is a recessive gene transmitted by typical Mendelian mechanisms.

Answer to Question 2

The most common disorder that results from a chromosome abnormality is Down syndrome. These abnormalities also can occur in the number of sex chromosomes, resulting in intellectual disability syndromes such as Klinefelter's (XXY, a disorder in which males have an extra X chromosome) and Turner's (XO, a disorder in which women are missing a second X chromosome).