22Q11 DELETIONS AND CARDIAC DISEASE

Chromosome 22q11 deletions constitute one of the most frequent genetic mutations associated with congenital heart disease. The finding of ab normalities within this locus in patients with DiGeorge syndrome provi ded the first evidence linking conotruncal and aortic arch anomalies w ith 22q11.2 mutations. Once non-syndromic patients with identical card iac defects were also found to exhibit deletions within 22q11.2, stron g support was generated for the concept that either a single gene defe ct, or a group of genes operating together, account for isolated cases of congenital heart disease. Recent advances in the characterization of the genes which comprise this region has brought us closer to the u ltimate goal of isolating candidate disease genes, The understanding o f how these genes (and those genes soon to be identified) regulate bio logical processes will hasten progress towards insight into the mechan isms leading to specific congenital heart lesions. This knowledge will bring us closer to comprehension of the genetic basis of normal cardi ovascular development.