Fragile X syndrome occurs because the person has
A)a thin area on the X chromosome.
B)an extra X chromosome.
C)a missing X chromosome.
D)an X chromosome in pair 21 rather than a Y.

Question

Quizplus · Accepted Answer

Fragile X syndrome is caused by a genetic mutation where there is a fragile site on the X chromosome, specifically an expansion of the CGG trinucleotide repeat affecting the FMR1 gene. This does not involve an extra X chromosome, a missing X chromosome, or an X chromosome in an abnormal location.

Fragile X Syndrome Occurs Because the Person Has