Mark was diagnosed with a moderate intellectual disability and would be described as a loving and responsive child,who is making progress in a specially tailored educational program. Mark's condition is the result of his receiving an extra chromosome from his mother,who was 48 years old when he was born.Mark has
A) cretinism.
B) phenylketonuria (PKU).
C) Down syndrome.
D) fragile-X syndrome.

Question

Quizplus · Accepted Answer

Mark's condition is consistent with Down syndrome, which results from the presence of an extra copy of chromosome 21. It is not consistent with cretinism or PKU, which are both genetic disorders with different symptoms, nor is it consistent with fragile-X syndrome, which is caused by a mutation on the X chromosome.

Mark Was Diagnosed with a Moderate Intellectual Disability and Would