title: Limited phenotypic variation of hypocalcified amelogenesis imperfecta in a Danish five-generation family with a novel FAM83H nonsense mutation.
abstract: BACKGROUND.  Autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI) is a disease with severe dental manifestations. OBJECTIVES.  The aims were by means of a genome-wide linkage scan to search for the gene underlying the ADHCAI phenotype in a Danish five-generation family and to study the phenotypic variation of the enamel in affected family members. RESULTS.  Significant linkage was found to a locus at chromosome 8q24.3 comprising the gene FAM83H identified to be responsible for ADHCAI in other families. Subsequent sequencing of FAM83H in affected family members revealed a novel nonsense mutation, p.Y302X. Limited phenotypic variation was found among affected family members with loss of translucency and discoloration of the enamel. Extensive posteruptive loss of enamel was found in all teeth of affected subjects. The tip of the cusps on the premolars and molars and a zone along the gingival margin seemed resistant to posteruptive loss of enamel. We have screened FAM83H in another five unrelated Danish patients with a phenotype of ADHCAI similar to that in the five-generation family, and identified a de novo FAM83H nonsense mutation, p.Q452X in one of these patients. CONCLUSION.  We have identified a FAM83H mutation in two of six unrelated families with ADHCAI and found limited phenotypic variation of the enamel in these patients.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Aarhus University, Denmark. dorte.haubek@odontologi.au.dk
authors.forename: Dorte
authors.initials: D
authors.lastname: Haubek
authors.forename: Hans
authors.initials: H
authors.lastname: Gjørup
authors.forename: Lillian G
authors.initials: LG
authors.lastname: Jensen
authors.forename: Inger
authors.initials: I
authors.lastname: Juncker
authors.forename: Mette
authors.initials: M
authors.lastname: Nyegaard
authors.forename: Anders D
authors.initials: AD
authors.lastname: Børglum
authors.forename: Sven
authors.initials: S
authors.lastname: Poulsen
authors.forename: Jens M
authors.initials: JM
authors.lastname: Hertz
mesh_terms: D000293:Adolescent; D000328:Adult; D000566:Amelogenesis / Q000235:genetics*; D000567:Amelogenesis Imperfecta / Q000235:genetics* / Q000473:pathology; D002648:Child; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D018389:Codon, Nonsense; D004252:DNA Mutational Analysis; D003718:Denmark; D003743:Dental Enamel / Q000473:pathology; D005192:Family Health; D005260:Female; D008040:Genetic Linkage; D055106:Genome-Wide Association Study; D006801:Humans; D008297:Male; D010375:Pedigree; D010641:Phenotype; D011506:Proteins / Q000235:genetics*; D014074:Tooth Calcification / Q000235:genetics*
chemical_list: D018389:Codon, Nonsense; C527308:FAM83H protein, human; D011506:Proteins