Causes of the phenotype-genotype dissociation in DiGeorge syndrome: clues from mouse models

Heterozygous deletions within human chromosome 22q11.2 are the genetic basis of DiGeorge syndrome (DGS), the most common deletion syndrome known in humans. To elucidate the molecular mechanism underlying this disease, researchers focused their attention on mouse genetics, creating animals carrying deletions of regions syntenic to the human DGS locus or targeted mutations of individual genes. Although some of these mouse mutants recapitulate many of the phenotypic features of DGS, they do not fully explain the complex genetics of the human disease. This article gives a short overview and comments on the most recent advances in this field.