Fragile X Syndrome Is a Human Disease Caused by a Trinucleotide

Multiple Choice

Fragile X syndrome is a human disease caused by a trinucleotide repeat expansion that results in loss-of-function of the FMR1 gene on the X chromosome.An animal model with most features of this syndrome could be created by

A) adding a transgene containing a mutant copy of the FMR1 gene to a mouse or primate genome.
B) adding a transgene containing a wild-type copy of the FMR1 gene to a mouse or primate genome.
C) knocking out both copies of the FMR1 gene from a mouse or primate genome.
D) knocking out one copy of the FMR1 gene from a mouse or primate genome.