X-linked hypophosphatemia (XLH) represents the most common form of familial hypophosphatemia. Although significant advances have been made in the treatment of bone pathology, patients undergoing therapy continue to experience significantly decreased oral health-related quality of life. The following study addresses this persistent oral disease by further investigating the effect of DMP1 expression on the differentiation of XLH dental pulp cells. Dental pulp cells were isolated from the third molars of XLH and healthy controls and stable transduction of full-length human DMP1 were achieved. RNA sequencing was performed to evaluate the genetic changes following the induction of odontogenic differentiation. RNAseq data shows the upregulation of inhibitors of the canonical Wnt pathway in XLH cells, while constitutive expression of full-length DMP1 in XLH cells reversed this effect during odontogenic differentiation. These results imply that inhibition of the canonical Wnt pathway may contribute to the pathophysiology of XLH and suggest a new therapeutic strategy for the management of oral disease.
Humans ; Familial Hypophosphatemic Rickets ; Wnt Signaling Pathway ; Dental Pulp ; Quality of Life ; Cell Differentiation

X-linked hypophosphatemia (XLH) is a rare disease of elevated fibroblast growth factor 23 (FGF23) production that leads to hypophosphatemia and impaired mineralization of bone and teeth. The clinical manifestations of XLH include a high prevalence of dental abscesses and periodontal disease, likely driven by poorly formed structures of the dentoalveolar complex, including the alveolar bone, cementum, dentin, and periodontal ligament. Our previous studies have demonstrated that sclerostin antibody (Scl-Ab) treatment improves phosphate homeostasis, and increases long bone mass, strength, and mineralization in the Hyp mouse model of XLH. In the current study, we investigated whether Scl-Ab impacts the dentoalveolar structures of Hyp mice. Male and female wild-type and Hyp littermates were injected with 25 mg·kg^-1 of vehicle or Scl-Ab twice weekly beginning at 12 weeks of age and euthanized at 20 weeks of age. Scl-Ab increased alveolar bone mass in both male and female mice and alveolar tissue mineral density in the male mice. The positive effects of Scl-Ab were consistent with an increase in the fraction of active (nonphosphorylated) β-catenin, dentin matrix protein 1 (DMP1) and osteopontin stained alveolar osteocytes. Scl-Ab had no effect on the mass and mineralization of dentin, enamel, acellular or cellular cementum. There was a nonsignificant trend toward increased periodontal ligament (PDL) attachment fraction within the Hyp mice. Additional PDL fiber structural parameters were not affected by Scl-Ab. The current study demonstrates that Scl-Ab can improve alveolar bone in adult Hyp mice.
Mice ; Male ; Female ; Animals ; Familial Hypophosphatemic Rickets/metabolism* ; Bone and Bones/metabolism* ; Tooth/metabolism* ; Periodontal Ligament/metabolism*

Elevated fibroblast growth factor 23 (FGF23) in X-linked hypophosphatemia (XLH) results in rickets and phosphate wasting, manifesting by severe bone and dental abnormalities. Burosumab, a FGF23-neutralizing antibody, an alternative to conventional treatment (phosphorus and active vitamin D analogs), showed significant improvement in the long bone phenotype. Here, we examined whether FGF23 antibody (FGF23-mAb) also improved the dentoalveolar features associated with XLH. Four-week-old male Hyp mice were injected weekly with 4 or 16 mg·kg^-1 of FGF23-mAb for 2 months and compared to wild-type (WT) and vehicle (PBS) treated Hyp mice (n = 3-7 mice). Micro-CT analyses showed that both doses of FGF23-mAb restored dentin/cementum volume and corrected the enlarged pulp volume in Hyp mice, the higher concentration resulting in a rescue similar to WT levels. FGF23-mAb treatment also improved alveolar bone volume fraction and mineral density compared to vehicle-treated ones. Histology revealed improved mineralization of the dentoalveolar tissues, with a decreased amount of osteoid, predentin and cementoid. Better periodontal ligament attachment was also observed, evidenced by restoration of the acellular cementum. These preclinical data were consistent with the retrospective analysis of two patients with XLH showing that burosumab treatment improved oral features. Taken together, our data show that the dentoalveolar tissues are greatly improved by FGF23-mAb treatment, heralding its benefit in clinics for dental abnormalities.
Humans ; Male ; Mice ; Animals ; Familial Hypophosphatemic Rickets/pathology* ; Fibroblast Growth Factor-23 ; Retrospective Studies ; Fibroblast Growth Factors/metabolism* ; Bone and Bones/metabolism* ; Phosphates/therapeutic use*

OBJECTIVE: To investigate the effectiveness of single Taylor external fixator combined with biplanar osteotomy on correction of tibial multiplanar deformities. METHODS: Between October 2016 and December 2021, 11 patients with tibial multiplanar deformities (20 sides) were treated with single Taylor external fixator and biplanar osteotomy. Of them, 4 were male and 7 were female; the average age ranged from 13 to 33 years (mean, 21.9 years). Diagnosis included rickets severe genu varum deformity (7 cases, 14 sides), rickets severe genu valgum deformity (2 cases, 4 sides), multiple osteochondromatosis calf deformity (1 case, 1 side), neurofibromatosis medial lower leg anterior arch deformity with short of leg (1 case, 1 side). After fibular osteotomy and tibial multiplanar osteotomy, a Taylor external fixator was installed. After operation, the deformities were corrected successively and fixed completely. The osteotomy healed, then the external fixator was removed. Before operation and at 12 months after operation, the full-length X-ray films were taken. The leg-length discrepancy, medial proximal tibial angle (MPTA), lateral distal tibial angle (LDTA), posterior proximal tibial angle (PPTA), anterior distal tibial angle (ADTA), and tibial rotation angle were measured. The degree of lower limb deformity was scored with reference to a customized tibial mechanical axis scoring table. RESULTS: Osteotomy was successfully completed without neurovascular injury and other complications. The external fixator was adjusted for 28-46 days, with an average of 37 days, and the external fixator was worn for 136-292 days, with an average of 169 days. Mild needle infection during the fixation period occurred in 3 sides, refracture at the distal tibial osteotomy in 1 side after removing the external fixator, and nonunion of the distal fibular osteotomy in 1 side. All patients were followed up 369-397 days (mean, 375 days). At 12 months after operation, the lower limb discrepancy decreased, but there was no significant difference ( P>0.05). MPTA, LDTA, PPTA, ADTA, and tibial rotation angle improved, and the differences in LDTA, ADTA, and tibial rotation angle were significant ( P<0.05). The score of lower limb deformity was significantly higher than that before operation ( P<0.05), and the results were excellent in 9 sides, good in 8 sides, fair in 3 sides, with the excellent and good rate of 85%. CONCLUSION Single Taylor external fixator combined with biplanar osteotomy is effective in the correction of tibial multiplanar deformities.
Humans ; Male ; Female ; Adolescent ; Young Adult ; Adult ; Tibia/surgery* ; Osteotomy/methods* ; Rickets ; External Fixators ; Retrospective Studies ; Treatment Outcome

OBJECTIVES: To study the value of serum fibroblast growth factor 23 (FGF23) in the diagnosis of hypophosphatemic rickets in children. METHODS: A total of 28 children who were diagnosed with hypophosphatemic rickets in Children's Hospital of Nanjing Medical University from January 2016 to June 2021 were included as the rickets group. Forty healthy children, matched for sex and age, who attended the Department of Child Healthcare of the hospital were included as the healthy control group. The serum level of FGF23 was compared between the two groups, and the correlations of the serum FGF23 level with clinical characteristics and laboratory test results were analyzed. The value of serum FGF23 in the diagnosis of hypophosphatemic rickets was assessed. RESULTS: The rickets group had a significantly higher serum level of FGF23 than the healthy control group (P<0.05). In the rickets group, the serum FGF23 level was positively correlated with the serum alkaline phosphatase level (r_s=0.38, P<0.05) and was negatively correlated with maximum renal tubular phosphorus uptake/glomerular filtration rate (r_s=-0.64, P<0.05), while it was not correlated with age, height Z-score, sex, and parathyroid hormone (P>0.05). Serum FGF23 had a sensitivity of 0.821, a specificity of 0.925, an optimal cut-off value of 55.77 pg/mL, and an area under the curve of 0.874 in the diagnosis of hypophosphatemic rickets (P<0.05). CONCLUSIONS Serum FGF23 is of valuable in the diagnosis of hypophosphatemic rickets in children, which providing a theoretical basis for early diagnosis of this disease in clinical practice.
Child ; Humans ; Fibroblast Growth Factor-23 ; Fibroblast Growth Factors ; Familial Hypophosphatemic Rickets/diagnosis* ; Rickets, Hypophosphatemic/diagnosis*

OBJECTIVE: To detect pathological variant in a Chinese pedigree affected with X-linked hypophosphatemia (XLH). METHODS: Whole-exome sequencing was carried out to screen genetic variants in the proband and her parents. Candidate variant of the phosphate regulating gene with homologies to endopeptidases on the X chromosome (PHEX) was verified by Sanger sequencing of all members of the pedigree and the 100 healthy controls. Prenatal diagnosis was carried out on chorionic villi sample derived from the fetus of the proband. RESULTS: A c.1256G>A (p. Gly419Glu) variant was identified in the PHEX gene of the proband and all other patients from this pedigree. The same variant was not found among healthy members from this pedigree and the 100 healthy controls. Prenatal diagnosis suggested that the fetus also carried the c.1256G>A (p. Gly419Glu) variant. CONCLUSION The c.1256G>A (p. Gly419Glu) variant of the PHEX gene probably underlay the pathogenesis of XLH in this family. Discovery of the novel variant has enriched the mutational spectrum of the PHEX gene.
China ; Familial Hypophosphatemic Rickets ; Female ; Humans ; Mutation ; PHEX Phosphate Regulating Neutral Endopeptidase/genetics* ; Pedigree ; Pregnancy ; Prenatal Diagnosis

Objective. We aim to study the prevalence and risk factors of hypovitaminosis D among healthy adolescents in Kota Bharu, Kelantan based on the most recent Paediatric Consensus guideline. Methodology. Ten public schools were selected from Kota Bharu, Kelantan. We analysed their demography (age, gender, ethnicity, income), measured their anthropometry (height, weight, BMI) and finally analysed their vitamin D and intact- Parathyroid hormone levels. Results. The prevalence of hypovitaminosis D was 16.9% among healthy teenagers with mean age of 15.9±1.39 years. Multivariate analysis showed female gender (adjusted OR, 95% CI): 23.7 (5.64, 100.3) and Chinese 0.24 (0.07, 0.84) were the significant predictors for hypovitaminosis D. Conclusion. The prevalence of healthy adolescents with hypovitaminosis D in Kota Bharu, Kelantan was 16.9% using the most recent cut off value of 30 nmol/L from the global consensus 2016. Female and Malay were the significant risk factors associated with hypovitaminosis D. Higher cut off value would result in overestimation of prevalence rate of hypovitaminosis D.
Vitamin D Deficiency ; Rickets ; adolescents

Identification of certain abnormalities of the chest wall can be extremely helpful in correctly diagnosing a number of syndromic conditions and systemic diseases. Additionally, chest wall abnormalities may sometimes constitute diagnoses by themselves. In the present pictorial essay, we review a number of such conditions and provide illustrative cases that were retrospectively identified from our clinical imaging database. These include pentalogy of Cantrell, Klippel-Feil syndrome, cleidocranial dysplasia, Poland syndrome, osteopetrosis, neurofibromatosis type 1, Marfan syndrome, Gardner syndrome, systemic sclerosis, relapsing polychondritis, polymyositis/dermatomyositis, ankylosing spondylitis, hyperparathyroidism, rickets, sickle cell anemia, thalassemia, tuberculosis, septic arthritis of the sternoclavicular joint, elastofibroma dorsi, and sternal dehiscence.
Anemia, Sickle Cell ; Arthritis, Infectious ; Cleidocranial Dysplasia ; Diagnosis ; Gardner Syndrome ; Hyperparathyroidism ; Klippel-Feil Syndrome ; Marfan Syndrome ; Neurofibromatosis 1 ; Osteopetrosis ; Pentalogy of Cantrell ; Poland Syndrome ; Polychondritis, Relapsing ; Retrospective Studies ; Rickets ; Scleroderma, Systemic ; Spondylitis, Ankylosing ; Sternoclavicular Joint ; Thalassemia ; Thoracic Wall ; Tuberculosis

Vitamin D hydroxylation-deficient rickets type 1A (VDDR1A, OMIM 264700) is a rare autosomal recessive inherited disorder. Pathogenic variants in the CYP27B1 gene lead to loss of 1α-hydroxylase activity. We report the case of a 22-month-old toddler who presented with growth retardation and delayed development. The patient exhibited the typical laboratory findings of VDDR1A, including hypocalcemia (calcium: 5.2 mg/dL), elevated serum level of alkaline phosphatase (2,600 U/L), elevated serum level of intact-parathyroid hormone (238 pg/mL), low 1,25(OH)₂D₃ level (11.2 pg/mL), and normal 25(OH)D₃ level (40.7 ng/mL). His height and weight were 76.5 cm and 9.5 kg, respectively (both <3rd percentile). The Bayley Scales of Infant and Toddler Development II indicated significantly delayed development (mental development index <50, psychomotor development index <50). The patient was a compound heterozygous for two novel pathogenic variants in the CYP27B1 gene: c.57_69del (p.Glu20Profs*2) and c.171dupG (p.Leu58Alafs*275), inherited from his mother and father, respectively. The patient showed remarkable improvement after treatment with calcitriol and calcium carbonate.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase ; Alkaline Phosphatase ; Calcitriol ; Calcium Carbonate ; Databases, Genetic ; Fathers ; Humans ; Hypocalcemia ; Infant ; Mothers ; Rickets ; Vitamin D ; Vitamins ; Weights and Measures

Hepatic osteodystrophy is frequent complication in patients with chronic liver disease, particularly with chronic cholestasis. We report a male infant with congenital hepatoblastoma, who had osteodystrophy complicated by multiple bone fractures despite adequate supplementation of fat-soluble vitamins including vitamin D. He was born by Caesarean section because of a 7 cm–sized abdominal mass detected by prenatal ultrasonography. The pathologic diagnosis was hepatoblastoma, PRETEXT staging III or IV. Whole body bone scan at the time of diagnosis showed no abnormal uptake. Oral vitamin D3 of 2,000 IU/day was administered with other fat-soluble vitamins. Serum direct bilirubin level gradually increased up to 28.9 mg/dL at postnatal 6 days and was above 5 mg/dL until 110 days of age. Bony changes consistent with rickets became apparent in left proximal humerus since 48 days of age, and multiple bone fractures developed thereafter. With resolving cholestasis by chemotherapy, his bony lesions improved gradually after add-on treatment of bisphosphonate and parenteral administration of vitamin D with calcium. High level of suspicion and prevention of osteodystrophy is needed in patients with hepatoblastoma, especially when cholestasis persists.
Bilirubin ; Calcium ; Cesarean Section ; Cholecalciferol ; Cholestasis ; Diagnosis ; Drug Therapy ; Female ; Fractures, Bone ; Hepatoblastoma ; Humans ; Humerus ; Infant ; Liver Diseases ; Male ; Pregnancy ; Rickets ; Ultrasonography, Prenatal ; Vitamin D ; Vitamins