Kleefstra syndrome (chromosome 9q34.3 deletion) is a rare genetic disorder with 
less than 110 patients reported till date. We report a 4-month-old Caucasian 
girl with Kleefstra syndrome and Shone's complex, an association which has not 
been previously reported. Surgical planning for patients with Kleefstra syndrome 
and complex CHD can pose challenges due to an uncertain natural history and a 
risk of post-operative pulmonary hypertension.