Final answer:
Cri-du-chat syndrome, caused by a deletion on chromosome 5, leads to distinctive cries in infants and various physical and mental abnormalities seen in individuals as they age.
Step-by-step explanation:
Cri-du-chat syndrome is a genetic disorder that arises from a deletion of a portion of chromosome 5, specifically most of the small arm known as 5p. As a result, individuals with this syndrome display distinct nervous system abnormalities and physical features. One of the most notable characteristics is the high-pitched cry of affected infants, reminiscent of a cat's meow, from which the disorder gets its name. These cries are a direct consequence of the nervous system irregularities caused by the chromosomal deletion.
Due to this genetic alteration, affected individuals may face a range of physical and mental abnormalities throughout their development, as shown in the referenced figures depicting one individual at ages two, four, nine, and twelve. These images serve to illustrate the progressive nature of the syndrome's manifestations. Chromosomal structural rearrangements like deletions may lead to various other complications in offspring who survive these genetic changes, further confirming the impact of such chromosomal abnormalities on a person's health.