Objective: Amelogenesis imperfecta (AI) is a rare hereditary disorder affecting the quality and quantity of the tooth enamel. The purpose of this study was to identify the genetic etiology of hypoplastic AI families based on the candidate gene approach.
Materials and methods: We recruited three Turkish families with hypoplastic AI and performed a candidate gene screening based on the characteristic clinical feature to find the pathogenic genetic etiology.
Results: The candidate gene sequencing of the LAMB3 gene for family 1 revealed a heterozygous nonsense mutation in the last exon [c.3431C > A, p.(Ser1144*)]. FAM20A gene sequencing for families 2 and 3 identified a homozygous deletion [c.34_35delCT, p.(Leu12Alafs*67)] and a homozygous deletion-insertion (c.1109 + 3_1109 + 7delinsTGGTC) mutation, respectively.
Conclusion: The candidate gene approach can be successfully used to identify the genetic etiology of the AI in some cases with characteristic clinical features.
Clinical relevance: Identification of the genetic etiology of the AI will help both the family members and dentist understand the nature of the disorder. Characteristic clinical feature can suggest possible genetic causes.
Keywords: Amelogenesis imperfecta; Candidate gene sequencing; Deletion-insertion mutation; FAM20A; LAMB3; Nonsense mutation.