The second most common form of intellectual developmental disorder is ______.
A) Klinefelter's syndrome
B) Turner's syndrome
C) fragile X syndrome
D) Down syndrome

Question

Quizplus · Accepted Answer

Fragile X syndrome is the second most common form of intellectual developmental disorder (after Down syndrome) and is caused by a mutation in the FMR1 gene on the X chromosome. Klinefelter's syndrome and Turner's syndrome are genetic conditions but do not typically result in intellectual developmental disorder.

The Second Most Common Form of Intellectual Developmental Disorder Is