[Neurocristopathies and chromosome 22 deletions].

Microdeletions of 22q11.2 are associated with a wide range of congenital disorders involving structures derived from the third and fourth pharyngeal pouches. This observation suggests that one major gene playing a part in rhombencephalic neural crest cells migration is localized in this small genomic region. Seven new genes have already been mapped to this detected region. Even if there is no clear evidence for the involvement of one of these genes in the pathogenesis of the disorder, these new molecular data provide us with a very efficient diagnosis tool.