Oculofaciocardiodental syndrome: novel BCOR mutations and expression in dental cells.
Oculofaciocardiodental (OFCD) syndrome is a rare X-linked dominant condition. Mutations in BCOR have been described as causal in OFCD syndrome. Almost all BCOR mutations result in premature termination codons (PTCs); therefore, nonsense-mediated mRNA decay (NMD) might have an important role in pathogenesis. The purpose of this study was to identify BCOR mutations in two OFCD patients, if it present, and to clarify the pathogenesis of radiculomegaly using one OFCD patient's pulp and periodontal ligament (PDL) cells. In our genetic analysis, two novel BCOR mutations were found. We also examined the transcript levels and the effects of NMD using cultured pulp and PDL cells from one affected patient. BCOR expression was normal in pulp but reduced in PDL cells, which is consistent with the higher rates of NMD in PDL cells. The mutant PDL cells had unstable mutant transcripts and proliferated faster than did wild-type cells, but mutant pulp cells appeared normal by these measures. In summary, the nonsense and frameshift mutations, which introduce PTCs, were found to contribute to OFCD syndrome in our two patients. Furthermore, in PDL cells, the mutation resulting in a PTC corresponded to greater NMD, unstable mutant transcripts and increased cell proliferation, which may contribute to hyperactive root formation.
Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Thunyaporn
T
Surapornsawasd
1] Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan [2] Hard Tissue Genome Research Center, Tokyo Medical and Dental University, Tokyo, Japan.
Takuya
T
Ogawa
Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Michiko
M
Tsuji
1] Maxillofacial Orthognathics, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan [2] Hard Tissue Genome Research Center, Tokyo Medical and Dental University, Tokyo, Japan.
Keiji
K
Moriyama
D000293:Adolescent; D000328:Adult; D002386:Cataract / Q000151:congenital* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D049109:Cell Proliferation; D002478:Cells, Cultured; D018389:Codon, Nonsense; D003782:Dental Pulp / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006343:Heart Septal Defects / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008850:Microphthalmos / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D059365:Nonsense Mediated mRNA Decay; D010513:Periodontal Ligament / Q000378:metabolism* / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism
C411984:BCOR protein, human; D018389:Codon, Nonsense; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins