🧬ap biology review

Down's syndrome

Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 examWritten by the Fiveable Content Team • Last updated September 2025

Definition

Down's syndrome is a chromosomal disorder caused by the presence of an extra copy of chromosome 21. This leads to physical and intellectual developmental delays.

"Down's syndrome" also found in: