DLX3 mutation associated with autosomal dominant amelogenesis imperfecta with taurodontism

Department of Dentistry, Royal Children’s Hospital, Melbourne, AustraliaAmelogenesis imperfecta hypoplastic-hypoma-turation with taurodontism (AIHHT) is an auto-somaldominant(AD)traitassociatedwithenameldefectsandenlargedpulpchambers.Inthisstudy,we mapped an AIHHT family to human chromo-some 17 q21-q22 (lod score 3.3) and identify a twobasepair deletion (CT) at nucleotide 560 in DLX3associated with the disease. This mutation causesa frameshift altering the last two amino acids ofthe DNA-binding homeodomain introducing apremature stop codon truncating the proteinby 88 amino acids. This is the first report of amutation within the homeodomain of DLX3.Previous studies have shown a DLX3 mutationoutside the homeodomain associated with tricho-dento-osseous syndrome (TDO) suggesting TDOand some forms of AIHHT are allelic.