Polymorphisms of the noggin gene and mandibular micrognathia: a first approximation.

Mandibular micrognathia is a deficiency in mandibular growth that prevents tooth contact during mastication, interferes with phonation and even causes sleep apnea. Studies show that mutant mice for chd (chordin) and nog (noggin) genes, which are modulators of the Bone Morphogenic Protein (BMP), had mandibular defects ranging from mandibular hypoplasia to micrognathia and agnathia. The human NOG gene was the first BMP antagonist identified and it is essential for various late events in mandibular development, which require modulation of the BMP activity.