TBX1 and 22q11.2 deletion syndrome: The specific genetic cause of VCFS is a deletion in the long arm of chromosome 22 at the q11.2 band.(2, 3) Distal deletion of 4q and partial monosomy 10p has also been reported to cause a syndrome similar to VCFS.(4, 5) However, genetic defects could not be detected by fluorescence in situ hybridization (FISH) analysis in 10% of VCFS cases.(6, 7, 8, 9, 10, 11, 12) A spectrum of phenotypes, often collectively called CATCH22 (cardiac defect, anomaly of face, cleft palate, hypoparathyroidism), is associated with heterozygous deletions of chromosome 22q11.2.