title: [Identification of a novel mutation of DSPP gene in a Chinese family affected with dentinogenesis imperfecta shields type II].
abstract: OBJECTIVE
  To identify the causative mutation in a Chinese family affected with dentinogenesis imperfecta shields type II (DGI-II).
  
  
  METHODS
  With informed consent obtained from all participants, peripheral blood or chorionic villi samples were collected from the family members. Genomic DNA was extracted using a standard SDS-proteinase K-phenol/chloroform method. The whole coding region and exon/intron boundaries of the DSPP gene were amplified with polymerase chain reaction (PCR) and subjected to Sanger sequencing. To confirm the pathogenicity of the identified mutation, an Alu I recognition sequence was introduced into the mutant allele using mismatch primers by semi-nested PCR. Restriction fragment length polymorphism (RFLP) analysis was then carried out for all family members and 60 unrelated healthy controls. Meanwhile, mini-DSPP constructs were conducted to confirm the effect of the mutation in vitro.
  
  
  RESULTS
  A splicing site mutation, c.52-1G>A, which was located upstream of exon 3, was found in all three patients and the fetus of the proband. Restriction analysis confirmed that all unaffected individuals and the 60 healthy controls did not carry the same mutation. The expression of minigene showed that the exon 3 of the DSPP gene was skipped during the transcription.
  
  
  CONCLUSIONS
  A novel pathogenic splicing-mutation c.52-1G>A has been detected in a Chinese family affected with DGI-II, which enabled prenatal diagnosis for the fetus of the proband.
authors.affiliation: Department of Medical Genetics and National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Peking Union Medical College School of Basic Medicine, Beijing 100005, China. xiulizhao@ibms.pumc.edu.cn.
authors.forename: Yanshan
authors.initials: Y
authors.lastname: Liu
authors.forename: Yingzhi
authors.initials: Y
authors.lastname: Huang
authors.forename: Jinsong
authors.initials: J
authors.lastname: Gao
authors.forename: Shan
authors.initials: S
authors.lastname: Li
authors.forename: Xiuli
authors.initials: X
authors.lastname: Zhao
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002675:Child, Preschool; D003811:Dentinogenesis Imperfecta / Q000235:genetics*; D005091:Exons; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D010750:Phosphoproteins / Q000235:genetics*; D017354:Point Mutation; D012326:RNA Splicing; D012795:Sialoglycoproteins / Q000235:genetics*; D000099311:Dentin Sialophosphoprotein
chemical_list: D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein