Which of the following conditions is characterized by a mutation on chromosome 8q22?

Cohen syndrome is indeed characterized by a mutation on chromosome 8q22. This genetic condition is associated with distinctive physical and developmental features, including ocular abnormalities, intellectual disability, and specific facial characteristics such as a prominent forehead and thin upper lip. The mutation that causes Cohen syndrome affects genes involved in various bodily functions, leading to its characteristic features.

Prader-Willi syndrome, Turner syndrome, and Down syndrome are linked to different chromosomal abnormalities or mutations. Prader-Willi syndrome is typically associated with deletions or disruptions on chromosome 15. Turner syndrome involves the complete or partial absence of one of the X chromosomes, affecting females. Down syndrome is most commonly caused by an extra copy of chromosome 21, known as trisomy 21. Thus, the unique chromosomal mutation associated with Cohen syndrome on chromosome 8q22 is critical in distinguishing it from these other genetic conditions.