Edwards syndrome is another name for trisomy of which chromosome?

• A. Monosomy X.
• B. Trisomy 21.
• C. Turner syndrome.
• D. Trisomy 18 (Edwards syndrome).

Answer: (D)

Edwards syndrome is caused by trisomy 18, meaning there are three copies of chromosome 18 in each cell. This extra chromosome leads to a recognizable pattern of congenital anomalies and serious developmental problems, with many affected individuals not surviving infancy. It’s distinct from trisomy 21 (Down syndrome) and from Turner syndrome (monosomy X), which involve different chromosomal changes.