One in 10 million: a case of cleidocranial dysplasia and acute lymphoblastic leukaemia--more than just a coincidence?

Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal dysplasia affecting approximately one in a million individuals (Mendoza-Londono and Lee, 1993). The manifestations of CCD include delayed closure of cranial sutures, large fontanelles, hypoplastic or absent clavicles and dental abnormalities. RUNX2 (6p21) is the only known gene associated with CCD, and mutations are found in up to 70% of cases. A further 10% are caused by deletions or duplications affecting RUNX2. We review the oncogenic potential of the RUNX gene family and discuss the association between syndromic disorders and cancer.