A novel de novo mutation in LAMB3 causes localized hypoplastic enamel in the molar region

Amelogenesis imperfecta (AI) is a collection of diseases characterized by hereditary enamel defects and is heterogeneous in genetic etiology and clinical phenotype. In this study, we recruited a nuclear AI family with a proband having unique irregular hypoplastic pits and grooves in all surfaces of the deciduous molar teeth but not in the deciduous anterior teeth. Based on the candidate gene approach, we screened the laminin subunit beta 3 (LAMB3) gene and identified a novel de novo mutation in the proband. The mutation was a frameshift mutation caused by a heterozygous 7-bp deletion in the last exon (c.3452_3458delAGAAGCG, p.Glu1151Valfs*57). This study not only expands the mutational spectrum of the LAMB3 gene causing isolated AI but also broadens the understanding of genotype-phenotype correlations.