Disease Etiology
22q11.2 deletion syndrome (22q11.2DS) is a genetic disorder caused by a microdeletion on chromosome 22 (1). Individuals most commonly have a large deletion (85% of individuals), while the remainder may have smaller, nested deletions that fall most often within or at the proximal end of the region. The majority of cases of 22q11.2DS (90%) are not inherited from the individual’s parents, but instead arise from a spontaneous genetic mutation. However, the