Six novel mutations of the RUNX2 gene in Italian patients with cleidocranial dysplasia.

We report clinical and molecular findings in 14 patients with cleidocranial dysplasia (CCD), a well defined skeletal disorder with characteristic clinical findings and autosomal dominant inheritance. We identified ten heterozygous base changes in the RUNX2 gene, including six novel mutations [c.522insA, c.389G>A (W130X), c.662T>G (V221G), IVS2+T>A, c.1111_1129del19, and c.873_874delCA]. We did not establish a clear correlation between clinical features and genotype, the phenotypes of all patients analyzed falling within the range of variation described in CCD without an effect related to the length of the predicted protein. In two cases, however, a limb-girdle myopathy affecting the shoulder muscles was also identified. Our data add new variants to the repertoire of RUNX2 mutations in CCD.