OBJECTIVE: To explore the clinical and genetic characteristics of a Chinese pedigree affected with hereditary dentinogenesis imperfecta (DGI) type II. METHODS: Clinical data of the pedigree members were collected. Genomic DNA was extracted from peripheral blood samples and subjected to whole exome sequencing. RESULTS: Clinical characteristics of the affected family members have included amber teeth along with significant attrition, constricted roots and dentine hypertrophy leading to pulpal obliteration, which were suggestive of DGI type II. All of the affected members were found to have harbored a novel heterozygous c.2837delA (p.Asp946Valfs*368) variant of the DSPP gene which was predicted to be likely pathogenic. CONCLUSION The c.2837delA variant of the DSPP gene probably underlay the disease in this pedigree. Above finding has expanded the variant spectrum of DSPP gene and provided a basis for molecular diagnosis and genetic counseling for this pedigree.
Dentinogenesis Imperfecta/genetics* ; Extracellular Matrix Proteins/genetics* ; Humans ; Mutation ; Pedigree ; Phosphoproteins/genetics* ; Sialoglycoproteins/genetics*

The classification as well as the clinical manifestations of hereditary malformations of dentin are of great concern and have been deeply elucidated. The understanding of its genetic basis also increases progressively. Dentin sialophosphoprotein (DSPP) is the pathogenic gene of dentinogenesis imperfecta type Ⅱ, dentinogenesis imperfecta type Ⅲ and dentin dysplasia type Ⅱ. In this article, the classification of DSPP mutations as well as the resultant dysfunction of the mutant DSPP are summarized respectively and the corresponding clinical manifestations are analyzed. This work will provide a reference for the diagnosis and treatment of hereditary malformations of dentin.
Humans ; Dentinogenesis Imperfecta/pathology* ; Mutation ; Extracellular Matrix Proteins/genetics* ; Phosphoproteins/genetics* ; Sialoglycoproteins/genetics* ; Dentin/pathology*

OBJECTIVE: To detect pathogenic variant in a child featuring Usher syndrome type II. METHODS: Peripheral blood samples of the child and his parents were collected for the analysis of variants of hearing impairment-related genes. The findings were verified in 100 individuals with normal hearing. RESULTS: The child was found to harbor compound heterozygous variants of the USH2A gene, namely c.8224-1G>C in intron 41 and c.5678C>G(p.Ser1893X) in exon 28, which were inherited respectively from his mother and father. Based on the American College of Medical Genetics and Genomics standards and guidelines, both c.8224-1G>C and c.5678C>G(p.Ser1893X) variants of USH2A gene were predicted to be pathogenic(PVS1+PM2+PM3). CONCLUSION The compound heterozygous variants c.8224-1G>C and c.5678C>G of the USH2A gene probably underlay the disease in this child. Above finding has enriched the spectrum of USH2A gene variants.
Child ; Exons ; Extracellular Matrix Proteins/genetics* ; Family ; Humans ; Introns ; United States ; Usher Syndromes/genetics*

Kallmann syndrome (KS) is a clinically and genetically heterogeneous disorder that occurs in either an inherited or a sporadic manner. KS results from failed embryonic migration of GnRH-1 neurons from the nasal placode to the hypothalamus, due to the abnormal development of olfactory nerves and bulbs. Hypogonadotropic hypogonadism is related to GnRH deficiency, and anosmia is associated with the absence or hypoplasia of olfactory bulbs and tracts. KS patients can also present some non-reproductive or non-olfactory anomalies in addition to the above typical symptoms. For the high complexity of the molecular genetic mechanism of KS, to date, only 6 KS-related genes have been identified. The KAL1 gene is responsible for the X chromosome-linked recessive form of KS, while the fibroblast growth factor receptor 1 (FGFR1/KAL2) and fibroblast growth factor 8 (FGF8/KAL6) genes are related to the autosomal dominant form of the disease. However, the mutations in these 6 genes account for only about 25 - 30% of all KS cases, which suggests that other pathogenic genes involved in KS remain to be discovered. This article presents an overview on the studies of the pathogenic genes, clinical diagnosis and treatment of KS.
Extracellular Matrix Proteins ; genetics ; Humans ; Kallmann Syndrome ; genetics ; Mutation ; Nerve Tissue Proteins ; genetics ; Receptor, Fibroblast Growth Factor, Type 1 ; genetics

BACKGROUND: The mechanism by which mutant cartilage oligomeric matrix protein (COMP) induces a pseudoachondroplasia phenotype remains unknown, and the reason why a mutation of a minor protein of the growth plate cartilage causes total disruption of endochondral bone formation has not yet been determined. The current study was performed to investigate the effects of mutated COMP on the synthesis of the cartilage-specific major matrix proteins of Swarm rat chondrosarcoma chondrocytes. METHODS: The Swarm rat chondrosarcoma chondrocytes transfected with a chimeric construct, which consisted of a mutant gene of human COMP and an amino acid FLAG tag sequence, were cultured in agarose gel. Formation of extracellular proteoglycan and type-II collagen by the cells was evaluated by immunohistochemical staining and measuring the (35)S-sulfate incorporation. RESULTS: No difference was observed for the detection of type-II collagen among the cell lines expressing mutant COMP and the control cell lines. Histochemical staining of sulfated proteoglycans with safranin-O showed that lesser amounts of proteoglycans were incorporated into the extracellular matrix of the chondrocytes transfected with the mutant gene. (35)S-sulfate incorporation into the cell/matrix fractions demonstrated markedly lower radiolabel incorporation, as compared to that of the control cells. CONCLUSIONS: Mutation of COMP has an important impact on the processing of proteoglycans, rather than type-II collagen, in the three-dimensional culture of Swarm rat chondrosarcoma chondrocytes.
Aggrecans/analysis/*biosynthesis ; Animals ; Cells, Cultured ; Chondrocytes/*metabolism ; Chondrosarcoma/metabolism ; Collagen Type II/*biosynthesis ; Extracellular Matrix/*metabolism ; Extracellular Matrix Proteins/*genetics ; Glycoproteins/*genetics ; Humans ; Mutation ; Rats ; Transfection

OBJECTIVE: To explore the molecular basis for an individual with postnatal deafness and provide genetic counseling for her family. METHODS: Following extraction of genomic DNA from peripheral blood samples, 127 genes associated with deafness were subjected to targeted capturing and next generation sequencing. Suspected mutation was verified by Sanger sequencing. RESULTS: The proband was found to carry a homozygous c.1893C>A mutation in the TECTA gene, which is located in the tectorial membrane of inner ear and may cause premature termination of translation of TECTA protein. In addition, two heterozygous mutations, c.13010C>T and c.12790G>A, were found in the USH2A gene. Whilst the former is likely to be pathogenic, the latter has unknown clinical significance. Further analysis suggested that all three mutations have derived from the parents of the proband. CONCLUSION The homozygous c.1893C>A mutation of the TECTA gene probably underlies the proband's hearing loss which conformed to an autosomal recessive inheritance.
Deafness ; Extracellular Matrix Proteins ; genetics ; Female ; GPI-Linked Proteins ; genetics ; High-Throughput Nucleotide Sequencing ; Homozygote ; Humans ; Mutation ; Pedigree

OBJECTIVETo perform mutation analysis for a female with multiple epiphyseal dysplasia (MED) and provide pre-symptomatic and prenatal diagnosis.

METHODSMutation screening of cartilage oligomeric matrix protein (COMP) gene was carried out through targeted next-generation DNA sequencing and Sanger sequencing.

RESULTSA novel c.956 A>T resulting in substitution of Aspartic acid 319 for Valine (p.Asp319Val) has been identified in exon 9 of the COMP gene in the patient. As predicted by a SIFT software, above mutation can cause damage to the structure of COMP protein.

CONCLUSIONA novel c.956 A>T substitution mutation has been identified in a patient featuring MED.

Adult ; Base Sequence ; Cartilage Oligomeric Matrix Protein ; Exons ; Extracellular Matrix Proteins ; genetics ; Female ; Glycoproteins ; genetics ; Humans ; Matrilin Proteins ; Mutation ; Osteochondrodysplasias ; diagnosis ; genetics ; Polymorphism, Single Nucleotide ; Sequence Alignment

Our previous studies have demonstrated that Fam20C promotes differentiation and mineralization of odontoblasts, ameloblasts, osteoblasts and osteocytes during tooth and bone development. Ablation of the Fam20C gene inhibits bone and tooth growth by increasing fibroblast growth factor 23 in serum and causing hypophosphatemia in conditional knockout mice. However, control and regulation of the expression of Fam20C are still unknown. In this study, we generated a transgenic reporter model which expresses green fluorescence protein (GFP) driven by the Fam20C promoter. Recombineering was used to insert a 16 kb fragment of the mouse Fam20C gene (containing the 15 kb promoter and 1.1 kb of exon 1) into a pBluescript SK vector with the topaz variant of GFP and a bovine growth hormone polyadenylation sequence. GFP expression was subsequently evaluated by histomorphometry on cryosections from E14 to adult mice. Fluorescence was evident in the bone and teeth as early as E17.5. The GFP signal was maintained stably in odontoblasts and osteoblasts until 4 weeks after birth. The expression of GFP was significantly reduced in teeth, alveolar bone and muscle by 8 weeks of age. We also observed colocalization of the GFP signal with the Fam20C antibody in postnatal 1- and 7-day-old animals. Successful generation of Fam20C-GFP transgenic mice will provide a unique model for studying Fam20C gene expression and the biological function of this gene during odontogenesis and osteogenesis.
Animals ; Calcium-Binding Proteins ; genetics ; Extracellular Matrix Proteins ; genetics ; Green Fluorescent Proteins ; genetics ; HEK293 Cells ; Humans ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Odontogenesis ; genetics ; Osteogenesis ; genetics

Adult ; Asian Continental Ancestry Group ; genetics ; Extracellular Matrix Proteins ; genetics ; Humans ; Lipoid Proteinosis of Urbach and Wiethe ; genetics ; Male ; Mutation

The expression of dentin sialophosphoprotein (DSPP) is the marker for cells differentiated into odontoblasts. This study attempted to analyze the DSPP promoter and build the reporter LacZ expression system driven by this promoter, which allows convenient and quick detection of odontoblast cells. First, we separated the human dental mesenchymal cells in which the expression of DSPP can be effectively induced by dexamethasone. Second, four 5' flanking regions of human DSPP gene (- 4 000-+54, -2 500-+54, -1 447-+54 and -1 027-+54) were analyzed, the results showed that the highest promoter activity lied in the -2 500-+54 region. The promoter activity is reduced when the 5' flanking region was extended from -2 500 to -4 000 bp upstream from the transcription start site; The promoter activity are also decreased when the 5' flanking regions were shorted from -2 500 to -1 447 bp and from -1 447 to -1 027 bp, indicating that potential suppresser elements are lied in the region between -4 000 and -2 500 bp and potential activator elements are lied in the region between -2 500 and -1 027 bp. Then we constructed the lentiviral report vector phDSPP-LacZ containing the -2 500-+ 54 promoter region in front of the LacZ gene. The expression of LacZ was detected using X-Gal staining in both human dental mesenchymal cells and immortalized human dental mesenchymal cells infected with phDSPP-LacZ. The phDSPP-LacZ lentiviral vector may provide a more convenient method to detect the expression of DSPP in human odontogenic differentiation, tooth development and tooth regeneration studies.
Cell Differentiation ; Extracellular Matrix Proteins ; genetics ; Genes, Reporter ; Humans ; Lac Operon ; Odontoblasts ; cytology ; Phosphoproteins ; genetics ; Promoter Regions, Genetic ; Sialoglycoproteins ; genetics