What example of disease is associated with chromosomal deficiency?

The selection of cri-du-chat disease as an example of a disease associated with chromosomal deficiency is accurate because this condition is specifically linked to a deletion of a portion of chromosome 5. This genetic anomaly involves the loss of genetic material, which can lead to various developmental issues and physical abnormalities characteristic of the syndrome, including a distinctive high-pitched cry that resembles that of a cat, which is how the disease gets its name.

In contrast, Down syndrome is primarily caused by an extra copy of chromosome 21, which is an example of a chromosomal excess rather than a deficiency. Turner syndrome involves the absence of one X chromosome in females, which is technically a form of chromosomal abnormality but differs from cri-du-chat in that it is characterized by the loss of an entire chromosome rather than a specific segment. Huntington's disease, on the other hand, is linked to a mutation in a single gene (HTT) on chromosome 4, rather than a chromosomal deficiency. Each of these conditions illustrates different types of chromosomal or genetic abnormalities, highlighting why cri-du-chat disease is the best example of a chromosomal deficiency among the options provided.