<prompt> A Down syndrome patient is posted for surgery, the necessary preoperative investigation to be done is:EchocardiographyCT brainX-ray cervical spineUSG abdomen  <response>: a. Echocardiography c. X-ray cervical spineRef: Nelsons 20e p 610-615, Ghai 8e p 637-639Congenital heart diseases are more common in Down syndrome in 50, than atlantoaxial instability 20; so a preoperative echocardiogram is warranted, so that management of child can be planned accordingly. 