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Anatomical Record (Hoboken, N.J. : 2007) Mar 2024Osteogenesis imperfecta (OI), a disorder of type I collagen, causes skeletal deformities as well as defects in dental tissues, which lead to increased enamel wear and...
Osteogenesis imperfecta (OI), a disorder of type I collagen, causes skeletal deformities as well as defects in dental tissues, which lead to increased enamel wear and smaller teeth with shorter roots. Mice with OI exhibit similar microstructural dentin changes, including reduced dentin tubule density and dentin cross-sectional area. However, the effects of these mutations on gross dental morphology and dental tissue volumes have never been characterized in the osteogenesis imperfecta murine (OIM) mouse model. Here we compare mineralized dental tissue measurements of OIM mice and unaffected wild type (WT) littermates at the juvenile and adult stages. The maxillary and mandibular incisors and first molars were isolated from microCT scans, and tissue volumes and root length were measured. OIM mice have smaller teeth with shorter roots relative to WT controls. Maxillary incisor volumes differed significantly between OIM and WT mice at both the juvenile and young adult stage, perhaps due to shortening of the maxilla itself in OIM mice. Additionally, adult OIM mice have significantly less crown enamel volume than do juveniles, potentially due to loss through wear. Thus, OIM mice demonstrate a dental phenotype similar to humans with OI, with decreased tooth size, decreased root length, and accelerated enamel wear. Further investigation of dental development in the OIM mouse may have important implications for the development and treatment of dental issues in OI patients.
Topics: Mice; Humans; Animals; Osteogenesis Imperfecta; Collagen Type I; Phenotype; Mutation; Incisor; Disease Models, Animal
PubMed: 37638385
DOI: 10.1002/ar.25306 -
Zhonghua Kou Qiang Yi Xue Za Zhi =... Aug 2023Dentin dysplasia type Ⅱ (DD-Ⅱ) is a subtype of hereditary dentin disorders. The dentin sialophosphoprotein (DSPP) gene has been revealed to be the causative gene,...
Dentin dysplasia type Ⅱ (DD-Ⅱ) is a subtype of hereditary dentin disorders. The dentin sialophosphoprotein (DSPP) gene has been revealed to be the causative gene, whose mutations could affect the normal tooth development process. The lesions involve both deciduous and permanent dentition, mainly manifested as tooth discoloration, attrition and even the subsequent malocclusion. If not treated in time, it will significantly affect the physical and psychological health of patients. The disease is difficult to be diagnosed in clinic accurately as its low incidence and hidden manifestations. The present article aims to discuss the clinical and radiographic characteristics, diagnosis, treatment of DD-Ⅱ, in order to improve the overall understanding on DD-Ⅱ for clinicians.
Topics: Humans; Dentin Dysplasia; Dentinogenesis Imperfecta; Sialoglycoproteins; Tooth; Mutation; Extracellular Matrix Proteins; Phosphoproteins; Dentin
PubMed: 37550036
DOI: 10.3760/cma.j.cn112144-20230410-00148 -
Endocrine Journal Jul 2023Osteogenesis imperfecta (OI) is an inherited disease characterized by bone fragility due to impaired type I collagen. Although orthopedic management is improving, other... (Review)
Review
Osteogenesis imperfecta (OI) is an inherited disease characterized by bone fragility due to impaired type I collagen. Although orthopedic management is improving, other complications are poorly understood. We describe three patients with OI with unruptured intracranial aneurysm (IA) detected by magnetic resonance angiography (MRA) screening of 14 patients. Case 1 was a 73-year-old woman with type 1 OI with blue sclera, vertebral compression fractures, and impaired hearing. Lumbar spine bone mineral density (BMD) was preserved (young adult mean (YAM): 86%). MRA revealed an IA in the right internal carotid artery. Case 2 was a 43-year-old man with type 4 OI and leg-length discrepancy due to left femoral neck fracture. Lumbar spine BMD was decreased (YAM: 61%). MRA showed an IA in the left anterior cerebral artery. Case 3 was a 35-year-old woman with type 3 OI with blue sclera, dentinogenesis imperfecta, deformity of the long bones, and severe scoliosis. She had undergone spine surgery and needed wheelchair assistance. The YAM of the femoral neck BMD was 71%. MRA indicated an IA in the right posterior communicating artery. The prevalence of IA in our series of patients with OI was 21%, which is higher than the reported prevalence of unruptured IA in the Japanese general population (2.2%), suggesting that IA may be a complication of OI. Our literature review revealed no cases of OI with unruptured IA, but 11 cases of OI with subarachnoid hemorrhage. IA seems unrelated to OI type, sex, or age. We recommend MRA of adults with OI.
Topics: Male; Female; Young Adult; Humans; Aged; Adult; Osteogenesis Imperfecta; Intracranial Aneurysm; Fractures, Compression; Spinal Fractures; Collagen Type I; Bone Density
PubMed: 37164684
DOI: 10.1507/endocrj.EJ22-0620 -
International Endodontic Journal Aug 2023Biallelic loss-of-function FAM20A mutations cause amelogenesis imperfecta (AI) type IG, better known as enamel renal syndrome (ERS), characterized by severe enamel...
AIM
Biallelic loss-of-function FAM20A mutations cause amelogenesis imperfecta (AI) type IG, better known as enamel renal syndrome (ERS), characterized by severe enamel hypoplasia, delayed/failed tooth eruption, intrapulpal calcifications, gingival hyperplasia and nephrocalcinosis. FAM20A binds to FAM20C, the Golgi casein kinase (GCK) and potentiates its function to phosphorylate secreted proteins critical for biomineralization. While many FAM20A pathogenic mutations have been reported, the pathogeneses of orodental anomalies in ERS remain to be elucidated. This study aimed to identify disease-causing mutations for patients with ERS phenotypes and to discern the molecular mechanism underlying ERS intrapulpal calcifications.
METHODOLOGY
Phenotypic characterization and whole exome analyses were conducted for 8 families and 2 sporadic cases with hypoplastic AI. A minigene assay was performed to investigate the molecular consequences of a FAM20A splice-site variant. RNA sequencing followed by transcription profiling and gene ontology (GO) analyses were carried out for dental pulp tissues of ERS and the control.
RESULTS
Biallelic FAM20A mutations were demonstrated for each affected individual, including 7 novel pathogenic variants: c.590-5T>A, c.625T>A (p.Cys209Ser), c.771del (p.Gln258Argfs*28), c.832_835delinsTGTCCGACGGTGTCCGACGGTGTC CA (p.Val278Cysfs*29), c.1232G>A (p.Arg411Gln), c.1297A>G (p.Arg433Gly) and c.1351del (p.Gln451Serfs*4). The c.590-5T>A splice-site mutation caused Exon 3 skipping, which resulted in an in-frame deletion of a unique region of the FAM20A protein, p.(Asp197_Ile214delinsVal). Analyses of differentially expressed genes in ERS pulp tissues demonstrated that genes involved in biomineralization, particularly dentinogenesis, were significantly upregulated, such as DSPP, MMP9, MMP20 and WNT10A. Enrichment analyses indicated overrepresentation of gene sets associated with BMP and SMAD signalling pathways. In contrast, GO terms related to inflammation and axon development were underrepresented. Among BMP signalling genes, BMP agonists GDF7, GDF15, BMP3, BMP8A, BMP8B, BMP4 and BMP6 were upregulated, while BMP antagonists GREM1, BMPER and VWC2 showed decreased expression in ERS dental pulp tissues.
CONCLUSIONS
Upregulation of BMP signalling underlies intrapulpal calcifications in ERS. FAM20A plays an essential role in pulp tissue homeostasis and prevention of ectopic mineralization in soft tissues. This critical function probably depends upon MGP (matrix Gla protein), a potent mineralization inhibitor that must be properly phosphorylated by FAM20A-FAM20C kinase complex.
Topics: Humans; Nephrocalcinosis; Amelogenesis Imperfecta; Dental Pulp; Dental Enamel Proteins; Mutation; Calcinosis; Gene Expression Profiling; Carrier Proteins
PubMed: 37159186
DOI: 10.1111/iej.13928 -
Oral Diseases Sep 2023This review aimed to summarize recent progress on syndromic dentin defects, promoting a better understanding of systemic diseases with dentin malformations, the... (Review)
Review
OBJECTIVE
This review aimed to summarize recent progress on syndromic dentin defects, promoting a better understanding of systemic diseases with dentin malformations, the molecules involved, and related mechanisms.
SUBJECTS AND METHODS
References on genetic diseases with dentin malformations were obtained from various sources, including PubMed, OMIM, NCBI, and other websites. The clinical phenotypes and genetic backgrounds of these diseases were then summarized, analyzed, and compared.
RESULTS
Over 10 systemic diseases, including osteogenesis imperfecta, hypophosphatemic rickets, vitamin D-dependent rickets, familial tumoral calcinosis, Ehlers-Danlos syndrome, Schimke immuno-osseous dysplasia, hypophosphatasia, Elsahy-Waters syndrome, Singleton-Merten syndrome, odontochondrodysplasia, and microcephalic osteodysplastic primordial dwarfism type II were examined. Most of these are bone disorders, and their pathogenic genes may regulate both dentin and bone development, involving extracellular matrix, cell differentiation, and metabolism of calcium, phosphorus, and vitamin D. The phenotypes of these syndromic dentin defects various with the involved genes, part of them are similar to dentinogenesis imperfecta or dentin dysplasia, while others only present one or two types of dentin abnormalities such as discoloration, irregular enlarged or obliterated pulp and canal, or root malformation.
CONCLUSION
Some specific dentin defects associated with systemic diseases may serve as important phenotypes for dentists to diagnose. Furthermore, mechanistic studies on syndromic dentin defects may provide valuable insights into isolated dentin defects and general dentin development or mineralization.
Topics: Humans; Dentinogenesis Imperfecta; Odontodysplasia; Osteogenesis Imperfecta; Dentin; Vitamin D
PubMed: 37094075
DOI: 10.1111/odi.14589 -
Oral Diseases Sep 2023The present study aims to investigate the mutation in a Chinese family with dentin dysplasia type II (DD-II) and to summarize mutation hotspots, clinical manifestations,... (Review)
Review
The present study aims to investigate the mutation in a Chinese family with dentin dysplasia type II (DD-II) and to summarize mutation hotspots, clinical manifestations, and disease management strategies. Phenotype analysis, clinical intervention, mutation screening, and cosegregation analysis within the enrolled family were performed. A summary of the reported mutations in the dentin phosphoprotein (DPP) region of dentin sialophosphoprotein (DSPP) was analyzed. Pathogenicity prediction analysis of the physical properties and function of DSPP variants was performed by bioinformatic processing. Clinical management strategies are discussed. A novel pathogenic mutation (c.2035delA) in the DPP region of DSPP was identified, which was cosegregated in the family. The immature permanent teeth of patients with DD-II presented with X-shaped root canal phenotypes. Most of the identified mutations for DD-II were clustered in the DPP region between nucleotides 1686-2134. Points of differential diagnosis, clinical interventions, and management strategies are proposed. This study revealed a novel DSPP frameshift mutation and presented new clinical features of DD-II. The locus involving nucleotides 1686-2134 of DSPP may represent a mutational hotspot for the disease. Appropriate management of DD-II at different stages is important to avoid the development of secondary dental lesions.
Topics: Humans; Dentin; Dentin Dysplasia; Dentinogenesis Imperfecta; Disease Management; Extracellular Matrix Proteins; Frameshift Mutation; Hyperplasia; Mutation; Nucleotides; Phosphoproteins; Sialoglycoproteins
PubMed: 36597617
DOI: 10.1111/odi.14494 -
Military Medicine Jul 2023Osteogenesis imperfecta (OI) is a heritable, collagen-related disorder with varying degrees of disease severity and systemic involvement. The hallmark of OI is bone...
INTRODUCTION
Osteogenesis imperfecta (OI) is a heritable, collagen-related disorder with varying degrees of disease severity and systemic involvement. The hallmark of OI is bone matrix fragility, but diverse effects related to structural integrity and impaired development of connective tissue can account for hearing loss, blue sclera, dentinogenesis imperfecta, frequent fractures, joint hypermobility, and cardiac valve or vessel fragility in some cases. There is emerging recognition of unique genetic mutations leading to OI including CREB3L1, which codes for an important transcription factor for differentiation of osteoblasts.
CASE PRESENTATION
We present a case of OI diagnosed in an active duty female with multiple prior fractures and heterozygous CREB3L1, a rare cause of OI.
CONCLUSION
This case highlights the importance of consideration of the variable phenotypes of OI and careful assessment of fracture history during evaluation at the Military Entrance Processing Station and subsequent encounters at military treatment facilities to improve readiness.
Topics: Humans; Female; Osteogenesis Imperfecta; Heterozygote; Cyclic AMP Response Element-Binding Protein; Military Personnel; Adult; Nerve Tissue Proteins
PubMed: 35978537
DOI: 10.1093/milmed/usac245