Novel complex disease allele mutations in cleidocranial dysplasia patients.

This study reports a novel identical complex disease allele harboring two non-synonymous mutations that were identified in two southern Chinese individuals of the same family with cleidocranial dysplasia (CCD). Blood samples were obtained from the proband, his parents, plus 100 matched control subjects. Exons 0 to 7 of the RUNX2 gene were amplified using specific primers and sequenced. Multiple sequence alignment and protein structure modeling was performed using ClustalW2 and MODBASE software while PolyPhen-2 and MutationTaster applications were employed to predict the disease-causing potential of the identified mutations. A complex disease allele in two affected individuals harboring two non-synonymous mutations in a cis-position on exons 4 (D273N) and 5 (P299L) were identified. The identified mutations were in the conserved region and changed the protein structure.