Fragile X syndrome is caused by expansion of a trinucleotide repeat in the 5′ UTR of the FMR-1 gene.What is the simplest way to detect this expansion?
A)PCR using genomic DNA as template and two primers that are complementary to repeats on either side of the expansion, followed by gel electrophoresis
B)PCR using genomic DNA as template and two primers, one complementary to the repeat region and the other complementary to unique sequence, followed by gel electrophoresis
C)PCR using two primers that are complementary to unique sequences on either side of the repeat region, followed by sequencing the PCR products
D)Direct exome sequencing using a microarray
E)Whole-genome sequencing

Question

Quizplus · Accepted Answer

The simplest way to detect the expansion of a trinucleotide repeat in the FMR-1 gene is to use PCR with primers that flank the repeat region, followed by sequencing the PCR products. This approach allows for the direct measurement of the size of the expansion.

Fragile X Syndrome Is Caused by Expansion of a Trinucleotide