Familial Odontoid Hypoplasia and Risk in Family Members

Odontoid hypoplasia is characterized by underdevelopment of the cervical vertebrae that can result in slippage of C1–C2 and neurological symptoms, especially after head or neck injury. Pediatricians are probably aware that children with Down syndrome are at risk for odontoid hypoplasia and need to be evaluated before participating in contact sports.

Until recently, odontoid hypoplasia was not thought to be familial. This report of a family with four otherwise healthy members who have odontoid hypoplasia suggests autosomal dominant inheritance of the disorder in some families.