Three human disorders−−fragile X syndrome, myotonic dystrophy, and Huntington's disease−−are conceptually linked by a common mode of molecular upset. Choose the phenomenon that links these disorders. Three human disordersfragile X syndrome, myotonic dystrophy, and Huntington's diseaseare conceptually linked by a common mode of molecular upset. Choose the phenomenon that links these disorders. All three are caused by disparate genes, but each gene was found to contain repeats of the same trinucleotide sequence. All three are X-linked, but each gene was found to contain repeats of the same trinucleotide sequence. All three are caused by disparate genes, but each gene was found to contain repeats of a unique trinucleotide sequence. All three are X-linked, but each gene was found to contain repeats of a unique trinucleotide sequence.