A The pedigree of the family. The arrow indicates the proband. B Sangersequence chromatograms of the RUNX2 gene show a single base change at nucleotide position 532 within exon 3 (c.532C>T, p.Q178X) in all affected individuals (I.1, II.1, and II.3). C Schematic representation of RUNX2-WT and the mutant Q178X showing the consequence of the mutation. The mutant allele with a single base change at position 532 (c.532C>T) generates a premature stop codon leading to a shorter protein (p.Q178X). NLS, nuclear localization signal; NMTS, nuclear matrix targeting signal; PST, proline/serine/threonine rich region; QA, polyglutamine and polyalanine domain; RHD, Runt homologous domain; VWRPY, carboxyterminal pentapetide; WT, wild type (III.1).