Example of a human geneticdisorder caused by an alteration in

chromosome structure (not a modification of an allele).

Cri du chat syndrome.

Explanation:

Maintenance of chromosomal structure is important for the proper functioning of the cell. The alteration or change in the chromosome structure may leads to the various genetic problem.

The cri du chat syndrome occurs due to the missing of the short arm of the chromosome number 5. The deletion in short arm of chromosome 5 is responsible for this syndrome. The infants that suffer from this syndrome has high pitched cry that is similar to the cry of a cat.

Thus, the answer is Cri du chat syndrome.