This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Impoant Genetic Syndromes, Subject name: Pediatrics
Most common chromosomal syndrome in children is? 
Select and explain. 
A. Fragile X-syndrome, B. Trisomy 17, C. Trisomy 21, D. Trisomy 13
C: Trisomy 21
Answer: C: Trisomy 21 
Explanation: **Down syndrome (Trisomy 21) is the most common of the chromosomal disorder. **Trisomy 16 is the most common trisomy overall, however most do not survive and die in utero Hence, among the live bihs, or among children, most common chromosomal abnormality is Trisomy 21