When three nucleotides are repeated , it is called a `` trinucleotide repeat '' ( for example : CAGCAGCAGCAG ... ) , and abnormalities in such regions can give rise to trinucleotide repeat disorders .
When three nucleotides are repeated , it is called a `` trinucleotide repeat '' ( for example : CAGCAGCAGCAG ... ) . Abnormalities in such regions can give rise to trinucleotide repeat disorders .