Over 90% of patients with classical DiGeorge syndrome or velocardiofacial syndrome (classical DGS/VCFS) have a de novo 22q11.2 deletion, and 7% of patients have an inherited 22q11.2 deletion from a parent. Deletions in this region are also associated with other phenotypes including isolated cardiovascular malformations and Opitz G syndrome. A small number of patients with a DGS/VCFS clinical phenotype without a 22q11.2 deletion (DGS/VCFS syndrome 2) have a deletion at chromosome 10p14. The main features of DGS/VCFS include heart defects, palatal abnormalities, characteristic facial features, learning difficulties, and immune deficiency. There is also a reciprocal duplication syndrome for the 22q11.2 region. The 22q11.2 duplication is highly variable. Findings range from apparently normal to intellectual disability/learning disability, delayed psychomotor development, growth retardation, and/or hypotonia. This laboratory performs deletion/duplication by MLPA for the 22q11.2 and 10p14 regions.