This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Radiology Q Bank, Subject name: Radiology
2day old baby brought to paediatric opd with history bilious vomitting, abdominal distension and mother was diagnosed polyhydramnios antenatally. XRAY was done shown below what is the most common anamoly associated with it 
Select and explain. 
A. TRISOMY 13, B. TRISOMY 15, C. TRISOMY 18, D. TRISOMY 21
D: TRISOMY 21
Answer: D: TRISOMY 21 
Explanation: The given image shows: Double bubble sign due to duodenal atresia Trisomy 21: Down syndrome Most common cause: Meiotic non-disjunction > Robesonian translocation GI manifestations: Duodenal atresia (Double bubble sign on X-ray). Other points to be remembered: Single bubble -Hyperophic pyloric stenosis Triple Bubble-Jejunal Atresia Mutliple Air fluid levels-Ileal Atresia