A genomic condition that may be responsible for some forms of fragile-X syndrome,as well as Huntington disease,involves ________.
A)F plasmids inserted into the FMR-1 gene
B)various lengths of trinucleotide repeats
C)multiple breakpoints fairly evenly dispersed along the X chromosome
D)multiple inversions in the X chromosome
E)single translocations in the X chromosome

Question

Quizplus · Accepted Answer

Fragile-X syndrome and Huntington disease are both caused by expansions of trinucleotide repeats in the FMR-1 and HTT genes, respectively. These repeats cause instability and eventual loss of gene function, leading to the symptoms of each disorder.

A Genomic Condition That May Be Responsible for Some Forms