A novel DSPP mutation causes dentinogenesis imperfecta type II in a large Mongolian family.
BACKGROUND
Several studies have shown that the clinical phenotypes of dentinogenesis imperfecta type II (DGI-II) may be caused by mutations in dentin sialophosphoprotein (DSPP). However, no previous studies have documented the clinical phenotype and genetic basis of DGI-II in a Mongolian family from China.


METHODS
We identified a large five-generation Mongolian family from China with DGI-II, comprising 64 living family members of whom 22 were affected. Linkage analysis of five polymorphic markers flanking DSPP gene was used to genotype the families and to construct the haplotypes of these families. All five DSPP exons including the intron-exon boundaries were PCR-amplified and sequenced in 48 members of this large family.


RESULTS
All affected individuals showed discoloration and severe attrition of their teeth, with obliterated pulp chambers and without progressive high frequency hearing loss or skeletal abnormalities. No recombination was found at five polymorphic markers flanking DSPP in the family. Direct DNA sequencing identified a novel A-->G transition mutation adjacent to the donor splicing site within intron 3 in all affected individuals but not in the unaffected family members and 50 unrelated Mongolian individuals.


CONCLUSIONS
This study identified a novel mutation (IVS3+3A-->G) in DSPP, which caused DGI-II in a large Mongolian family. This expands the spectrum of mutations leading to DGI-II.
Inner Mongolia University, Huhhot, China.
Haihua
H
Bai
Hasi
H
Agula
Qizhu
Q
Wu
Wenyu
W
Zhou
Yujing
Y
Sun
Yue
Y
Qi
Suya
S
Latu
Yujie
Y
Chen
Jiri
J
Mutu
Changchun
C
Qiu
D044466:Asian People / Q000235:genetics; D003811:Dentinogenesis Imperfecta / Q000235:genetics*; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005260:Female; D006239:Haplotypes; D006801:Humans; D008297:Male; D008986:Mongolia; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D010750:Phosphoproteins / Q000235:genetics*; D012326:RNA Splicing; D017422:Sequence Analysis, DNA; D012795:Sialoglycoproteins / Q000235:genetics*; D014071:Tooth Abnormalities; D000099311:Dentin Sialophosphoprotein
D016326:Extracellular Matrix Proteins; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000099311:Dentin Sialophosphoprotein