Question

Which structural chromosomal abnormality involves a chromosomal segment being copied and repeated?

Options

• Duplication

• Translocation

• Deletion

• Inversion

Answer 1

Duplication is a structural chromosomal abnormality in which a chromosomal segment is copied and repeated on the same chromosome. This results in gene overdose with variable effects depending on which genes are duplicated. Fragile X syndrome is an example involving a repeat expansion at Xq27.3 on the X chromosome.