This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Which is not cytogenetic abnormality in myclodysplastic syndrome 
Select and explain. 
A. Chromosome 5q deletion, B. Monosomy 7, C. Trisomy 8, D. Chromosome 20q deletion
D: Chromosome 20q deletion
Answer: D: Chromosome 20q deletion 
Explanation: Solution:
Adult → 5q deletion
Pediatric → monosomy 7
Trisomy 8 → 3 copies of MYC gene
These three are common genetic defects of MDS.