Atypical presentations of 22q11.2 deletion syndrome: explaining the genetic defects and genome architecture.

22q11.2 deletion syndrome, the most common microdeletion syndrome, exhibits a broad range of phenotypes, implying a cumbersome diagnosis due to atypical or paucisymptomatic presentations. We present two atypical cases of 22q11.2 deletion syndrome and suggest a preferential occurrence of the breakpoints in regions poor in repetitive elements of SINE/Alu family.