Chromosome 22q11.2 and 7q11.23 Microdeletions in Children with Congenital Heart Defects Detected by Fish Technique

Congenital heart defects (CHD) are the most common birth abnormalities and the leading non-infectious cause of mortality in infants. CHD may occur as a single abnormality or as part of a syndrome. Two of the associated syndromes are DiGeorge and Williams-Beuren. DiGeorge (DGS) syndrome is a variant of 22q11.2 microdeletion syndrome and is known as CATCH22 syndrome (cardiac abnormalities, anomalies of the face, thymus hypoplasia, cleft-palate and hypocalcemia). The most associated CHD are conotruncal defects. Williams-Beuren syndrome (WBS) is also a microdeletional syndrome characterised by CHD, facial abnormalities, neonatal hypocalcemia, neurological and behavioural disorders. The most associated CHD are the supravalvular aortic stenosis and supravalvular pulmonary stenosis. FISH (Fluorescence in Situ Hybridization) technique is now the standard investigation for the diagnosis of microdeletional syndromes. This study shows the importance of FISH analysis in patients with syndromic congenital disease.