This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics And Genetic Disorders, Subject name: Pediatrics
Which of these syndromes is associated with microcephaly? 
Select and explain. 
A. Down syndrome, B. Edward syndrome, C. Cri-du-chat syndrome, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Ans. D. All of theseMicrocephaly or small head is subdivided into primary and secondary microcephaly. Primary microcephaly usually follows a Mendelian pattern of inheritance or is associated with certain syndromes. Down syndrome (trisomy 21), Edward syndrome (trisomy 18), Cri-du-chat syndrome (5p-), and Cornelia de Lange syndrome are associated with microcephaly.