CATCH 22 - DiGeorge Syndrome / Velo-cardio-facial syndrome

CATCH 22 is an acronym for

C - Cardiac defects *
A - Abnormal Facies
T - Thymic (and parathyroid) hypoplasia
C - Cleft Palate
H - Hypocalcemia due to parathyroid hypoplasia

22 - It's the most common microdeletion syndrome and it affects Chr.22q11**

Further :

* " In a series of 545 patients with 22q11 deletions, 20% had no cardiac defects (ie, based on clinical examination and echocardiography findings). The most common cardiac anomalies included tetralogy of Fallot (17%), ventricular septal defect and interrupted aortic arch (14% each), pulmonary atresia/ventricular septal defect (10%), and truncus arteriosus (9%). Other anomalies included pulmonic stenosis, atrial septal defect, atrioventricular septal defect, and transposition of great arteries".

http://emedicine.medscape.com/article/135711-overview

** "DiGeorge anomaly is the most frequent contiguous gene deletion syndrome in humans. Microdeletion of chromosome 22 accounts for more than 90% of cases of DiGeorge anomaly. Deletions of chromosome 22q11.2 are found in the vast majority of patients with DiGeorge anomaly and VCFS."

Hope it's of some help.