Cleidocranial dysostosis

Cleidocranial dysostosis, also called cleidocranial dysplasia, is a congenital skeletal and dental condition caused by a defect in the RUNX2 gene, which governs bone formation, and is usually inherited in an autosomal dominant pattern, though it can also arise as a new mutation. Its defining feature is poorly developed or absent collarbones, sometimes allowing the shoulders to be brought together in front of the chest; in about ten percent of cases the clavicles are completely missing. Affected individuals are typically shorter than average and often have a prominent forehead, wide-set eyes, a flat nose and abnormal teeth, along with delayed closure of the skull's soft spots in infancy. Despite these distinctive skeletal and dental differences, cognitive development is generally unaffected and life expectancy for people with cleidocranial dysostosis is normal, making it primarily a condition managed through orthopedic and dental care rather than a life-limiting disease.