Chromosomal deletions occur when a segment of a chromosome is missing or lost. This can happen during cell division when chromosomes do not properly align or separate. The missing genetic material can lead to various health issues, depending on the size of the deletion and the genes involved. These deletions can result in genetic disorders, such as Cri du Chat syndrome, which is caused by a deletion on chromosome 5. Symptoms may include developmental delays, distinctive facial features, and other physical or cognitive challenges. Early diagnosis and intervention can help manage some of these conditions.