[Di George syndrome, exemplary rhomboencephalic neurocristopathy]

Di George's syndrome associates hypocalcemia and hyperphosphoremia (phosphocalcic disorders from absence of the parathyroids), cell immunity disorders related to agenesis or hypoplasia of the thymus, and large vessels malformations (pulmonary artery, aorta) with cardiac lesions. The disorder is the result of deletion of rhomboencephalic neural crests cells, Di George's syndrome being an exemplary rhomboencephalic neurocristopathy. This organic syndrome is associated with early disorders of the same neurological region (the rhomboencephalon), expressed clinically by sucking and swallowing disturbances and cardiorespiratory regulatory disorders. Early rhomboencephalic lesions can lead to velopalatal division and microretrognathism secondary to a lingual motility disturbance. The association of this neurocristopathy with a neural tube lesion constitutes a dysneurulation. Fetal and neonatal retrognathism are evidence of bulbar involvement. Di George's and Pierre Robin's syndromes constitute two fairly similar clinical expressions of the same embryonic deficiency of rhomboencephalic neurulation.