Which of the following forms of intellectual disabilities is caused by abnormal chromosomal development affecting the 21st pair of chromosomes?
A) Fragile X syndrome
B) Down syndrome
C) Tay-Sachs disease
D) PKU

Question

Quizplus · Accepted Answer

Down syndrome is caused by the presence of an extra copy of chromosome 21. Fragile X syndrome is caused by a mutation on the X chromosome. Tay-Sachs disease is caused by a deficiency in the enzyme hexosaminidase A. PKU is caused by a gene mutation on chromosome 12.

Which of the Following Forms of Intellectual Disabilities Is Caused