Hypoplastic AI with Highly Variable Expressivity Caused by ENAM Mutations
JOURNAL OF DENTAL RESEARCH, vol.97, no.9, pp.1064-1069, 2018 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 97 Issue: 9
- Publication Date: 2018
- Doi Number: 10.1177/0022034518763152
- Journal Name: JOURNAL OF DENTAL RESEARCH
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.1064-1069
- Keywords: amelogenesis imperfecta, enamel, tooth, enamelin, penetrance, whole exome sequencing, DOMINANT AMELOGENESIS IMPERFECTA, EPIDERMOLYSIS-BULLOSA, DELETION, IDENTIFICATION, DEFECTS, PROTEIN, LAMB3
- Istanbul University Affiliated: Yes
Abstract
Tooth enamel, the hardest tissue in the human body, is formed after a complex series of interactions between dental epithelial tissue and the underlying ectomesenchyme. Nonsyndromic amelogenesis imperfecta (AI) is a rare genetic disorder affecting tooth enamel without other nonoral symptoms. In this study, we identified 2 novel ENAM mutations in 2 families with hypoplastic AI by whole exome sequencing. Family 1 had a heterozygous splicing donor site mutation in intron 4, NM_031889; c.123+2T>G. Affected individuals had hypoplastic enamel with or without the characteristic horizontal hypoplastic grooves in some teeth. Family 2 had a nonsense mutation in the last exon, c.1842C>G, p.(Tyr614*), that was predicted to truncate the protein by 500 amino acids. Participating individuals had at least 1 mutant allele, while the proband had a homozygous mutation. Most interestingly, the clinical phenotype of the individuals harboring the heterozygous mutation varied from a lack of penetrance to a mild hypoplastic enamel defect. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations.