dup(22)(q11.2q11.2)

Epidemiology and Etiology:

· Majority are de novo

· Some are inherited

· Parent may be mildly affected or normal

Common sites:

·

Gross features:

· Normal to mild, highly variable phenotype

· Dysmorphic facial features maybe

· Heart malformations maybe

Histologic features:

·

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

· Ranges between 1.5 and 6 Mb

· Shares some breakpoints with DiGeorge:

· LCR2 (17 Mb)

· Common proximal breakpoint

· Also common proximal breakpoint for DGS

· Also breakpoint for type I CES

· LCR4 (20 Mb)

· 3 Mb duplication breakpoint

· Also type II CES breakpoint

· LCR5 (21.25 Mb)

· 4 Mb duplication breakpoint

· LCR7 (23 Mb)

· 6 Mb duplication breakpoint

· Note: BCR/ABL breakpoint is at LCR6 in between the last two

Other features:

· Normal to mild, highly variable phenotype

· mental retardation / learning difficulties

· delayed psychomotor development

· growth retardation

· hypotonia

References:

· Gardner RJM, Sutherland GR. Chromosome abnormalities and genetic counseling. Oxford University Press; 2004.

· Torres-Juan et al. BMC Medical Genetics 2007 8:14 doi:10.1186/1471-2350-8-14