A child has just been diagnosed with fragile X syndrome.The nurse recognizes that fragile X syndrome is:
A)a chromosomal defect affecting females only.
B)a chromosomal defect that follows the pattern of X-linked recessive disorders.
C)the second most common genetic cause of mental retardation.
D)the most common cause of noninherited mental retardation.

Question

Quizplus · Accepted Answer

Fragile X syndrome is the second most common cause of mental retardation after Down syndrome.Fragile X primarily affects males,follows the inheritance pattern of X-linked dominant with reduced penetrance.This is in distinct contrast to the classic X-linked recessive pattern in which all carrier females are normal,all affected males have symptoms of the disorder,and no males are carriers.

A Child Has Just Been Diagnosed with Fragile X Syndrome