Publication date: Available online 12 January 2017
Source:Archives of Oral Biology
Author(s): Young-Jae Kim, Youn Jung Kim, Jenny Kang, Teo Jeon Shin, Hong-Keun Hyun, Sang-Hoon Lee, Zang Hee Lee, Jung-Wook Kim
OBJECTIVESAmelogenesis imperfecta (AI) is a hereditary genetic defect affecting tooth enamel. AI is heterogeneous in clinical phenotype as well as in genetic etiology. To date, more than 10 genes have been associated with the etiology of AI. Amelogenin is the most abundant enamel matrix protein, most of which is encoded by the amelogenin gene in the X-chromosome (AMELX). More than 16 alternative splicing transcripts have been identified in the murine Amelx gene. The purposes of this study were to identify the genetic cause of an AI family.MATERIALS AND METHODSWe recruited a family with hypoplastic AI and performed mutational analysis on the candidate gene based on the clinical phenotype.RESULTSMutational analysis revealed a missense mutation in exon 6 (NM_182680.1; c.242C > T), which changes a sequence in a highly conserved amino acid (NP_872621.1; p.Pro81Leu). Furthermore, a splicing assay using a minigene displayed that the mutation changed the mRNA splicing repertory.CONCLUSIONSIn this study, we identified a novel AMELX missense mutation causing hypoplastic AI, and this mutation also resulted in altered mRNA splicing. These results will not only expand the mutation spectrum causing AI but also broaden our understanding of the biological mechanism of enamel formation.