1. Homozygous and compound heterozygous MMP20 mutations in amelogenesis imperfecta.
- Author
-
Gasse B, Karayigit E, Mathieu E, Jung S, Garret A, Huckert M, Morkmued S, Schneider C, Vidal L, Hemmerlé J, Sire JY, and Bloch-Zupan A
- Subjects
- Amelogenesis Imperfecta genetics, Apatites analysis, Base Sequence genetics, Calcium analysis, Child, Preschool, Codon, Nonsense genetics, Crystallography, Cytosine, Dental Enamel ultrastructure, Electron Probe Microanalysis, Exons genetics, Female, Genes, Recessive genetics, Humans, Magnesium analysis, Microscopy, Electron, Scanning, Minerals analysis, Mutation, Missense genetics, Sequence Deletion genetics, Thymine, Amelogenesis Imperfecta enzymology, Heterozygote, Homozygote, Matrix Metalloproteinase 20 genetics, Mutation genetics
- Abstract
In this article, we focus on hypomaturation autosomal-recessive-type amelogenesis imperfecta (type IIA2) and describe 2 new causal Matrix metalloproteinase 20 (MMP20) mutations validated in two unrelated families: a missense mutation p.T130I at the expected homozygous state, and a compound heterozygous mutation having the same mutation combined with a nucleotide deletion, leading to a premature stop codon (p.N120fz*2). We characterized the enamel structure of the latter case using scanning electron microscopy analysis and microanalysis (Energy-dispersive X-ray Spectroscopy, EDX) and confirmed the hypomaturation-type amelogenesis imperfecta as identified in the clinical diagnosis. The mineralized content was slightly decreased, with magnesium substituting for calcium in the crystal structure. The anomalies affected enamel with minimal inter-rod enamel present and apatite crystals perpendicular to the enamel prisms, suggesting a possible new role for MMP20 in enamel formation.
- Published
- 2013
- Full Text
- View/download PDF