title: Novel FAM20A mutation causes autosomal recessive amelogenesis imperfecta.
abstract: OBJECTIVE
  To relate the peculiar phenotype of amelogenesis imperfecta in a large Bedouin family to the genotype determined by whole genome linkage analysis.
  
  
  METHODS
  Amelogenesis imperfecta (AI) is a broad group of inherited pathologies affecting enamel formation, characterized by variability in phenotypes, causing mutations and modes of inheritance. Autosomal recessive or compound heterozygous mutations in FAM20A, encoding sequence similarity 20, member A, have been shown to cause several AI phenotypes. Five members from a large consanguineous Bedouin family presented with hypoplastic amelogenesis imperfecta with unerupted and resorbed permanent molars. Following Soroka Medical Center IRB approval and informed consent, blood samples were obtained from six affected offspring, five obligatory carriers and two unaffected siblings. Whole genome linkage analysis was performed followed by Sanger sequencing of FAM20A.
  
  
  RESULTS
  The sequencing unravelled a novel homozygous deletion mutation in exon 11 (c.1523delC), predicted to insert a premature stop codon (p.Thr508Lysfs*6).
  
  
  CONCLUSIONS
  We provide an interesting case of novel mutation in this rare disorder, in which the affected kindred is unique in the large number of family members sharing a similar phenotype.
authors.affiliation: The Morris Kahn Laboratory of Human Genetics at the National Institute for Biotechnology in the Negev (NIBN) and Faculty of Health Sciences, Ben Gurion University, Beer-Sheva, Israel. Electronic address: volodarm@bgu.ac.il.
authors.forename: Michael
authors.initials: M
authors.lastname: Volodarsky
authors.affiliation: Pediatric Dental Unit, Barzilai Medical Center, Ashkelon, Israel. Electronic address: ori@barzi.health.gov.il.
authors.forename: Uri
authors.initials: U
authors.lastname: Zilberman
authors.affiliation: The Morris Kahn Laboratory of Human Genetics at the National Institute for Biotechnology in the Negev (NIBN) and Faculty of Health Sciences, Ben Gurion University, Beer-Sheva, Israel; The Genetics Institute, Soroka Medical Center, Beer-Sheva, Israel. Electronic address: obirk@bgu.ac.il.
authors.forename: Ohad S
authors.initials: OS
authors.lastname: Birk
mesh_terms: D000293:Adolescent; D000567:Amelogenesis Imperfecta / Q000235:genetics*; D003241:Consanguinity; D003746:Dental Enamel Proteins / Q000235:genetics*; D005091:Exons; D005260:Female; D005838:Genotype; D006720:Homozygote; D006801:Humans; D007557:Israel; D010375:Pedigree; D010641:Phenotype; D016133:Polymerase Chain Reaction
chemical_list: D003746:Dental Enamel Proteins; C571509:FAM20A protein, human
keywords: Enamel; Gene; Linkage analysis; Molars; Sequencing; Stop codon