• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.152-157
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• 2005

Hypophosphatemia rickets, also known as Vitamin D-resistant rickets(VDRR) and refractory rickets, is a form of rickets which is resistant to the usual doses of vitamin D. VDRR is characterized by decreased renal tubular reabsorption of inorganic phosphate and is easily diagnosed by a normal blood calcium, hypophosphatemia, and slightly elevated alkaline phosphatase. Clinical features of Hypophosphatemia rickets included lateral bowing deformities of the legs, short stature, scoliosis, and enlargement of wrist and ankles. Dental finding in patient with VDRR were spontaneous dental abscesses in caries free teeth and other dental findings included delayed eruption, delayed apical closure, thin and hypoplastic enamel, absent or poorly defined lamina dura, enlarged pulp chambers, and numerous accessory canals and pulp horns that extend up and into the dentinoenamel junction. we reported the clinical feature and treatment of VDRR child who was referred from the department of pediatrics for early loss of primary teeth and its treatment.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.237-240
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• 1999

The presence of polyostotic fibrous dysplasia of bone, hyperpigmented skin macules, and precocious sexual development in children is known as the McCune-Albright syndrome. In addition to the described in McCune-Albright syndrome, other endocrinopathies have been reported including hyperthyroidism, acromegaly, Cushing syndrome and vitamin D resistant rickets. The case describes a 6-year-old boy showing bony deformities due to polyostotic fibrous dysplasia, hyperpigmented skin macules, hyperthyroidism and vitamin D resistant rickets. The purpose of this report is to describe a patient of McCune-Albright syndrome with vitamin D resistant rickets which is very rare.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.665-668
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• 2005

"Rickets" is the term applied to impaired mineralization at epiphyseal growth plate, resulting in deformity and impaired linear growth of long bones. Rickets may arise as a result of vitamin D deficiency or abnormality in metabolism. Vitamin D-dependent rickets(VDDR) is rare autosomal recessive disorder in which affected individuals have clinical features of vitamin D deficiency. In 1961, Prader first described this disorder including severe clinical features of rickets, such as hypophosphatemia, hypocalcemia, muscle weakness and seizure. Two distinctive hereditary defects, type I VDDR and type II VDDR have been recognized in vitamin D metabolism. Type I VDDR may be due to congenital defects of renal 1 ${\alpha}$-hydroxylase, the enzyme responsible for conversion of $25(OH)D_3$. These patients have low to detectable $1,25(OH)_2D_3$ in presence of normal to raised $25(OH)D_3$. In type II VDDR, renal production of $1,25(OH)_2D_3$ is intact but $1,25(OH)_2D_3$ is not used effectively and target organ resistant to $1,25(OH)_2D_3$ is respectively derived from the abnormality in the vitamin D receptor. We report a case of a 25 month-old girl with typical clinical features of VDDR type I rickets, hypocalcemia, increased alkaline phosphatase and secondary hyperparathyroidism.

• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1143-1146
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• 2003

Rickets is a nutritional disorder which is caused either by deficiency of vitamin D or by a defective activation of vitamin D. In these days, even though the incidence of rickets has decreased through adequate nutritional support, we sometimes experience rickets in babies receiving a prolonged special diet as therapy for chronic diarrhea, or those subject to a in receiving the prolonged elimination of milk because of allergy. But there are no reports about rickets caused by absolute elimination of milk because of allergies in Korea. We report here a case of rickets developed after feeding on Sunsik( a mixture of several grain and fruits powder) during a seven months period in an 8-month-old male patient. This male infant manifested vomiting, poor feeding, decreased serum calcium and 25-hydroxycholecalciferol levels, and markedly increased serum alkaline phosphatase and parathyroid hormone levels. Skeletal X-rays showed cupping and fraying in distal metaphyses of radius and ulna, and generalized osteopenia. The patient improved with vitamin D and calcium therapy.

• Clinical and Experimental Pediatrics
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• v.54 no.2
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• pp.51-54
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• 2011

Vitamin D is present in two forms, ergocalciferol (vitamin $D_2$) produced by plants and cholecalciferol (vitamin $D_3$) produced by animal tissues or by the action of ultraviolet light on 7-dehydrocholesterol in human skin. Both forms of vitamin D are biologically inactive pro-hormones that must undergo sequential hydroxylations in the liver and the kidney before they can bind to and activate the vitamin D receptor. The hormonally active form of vitamin D, 1,25-dihydroxyvitamin D3 $[1,25(OH)_2D]$, plays an essential role in calcium and phosphate metabolism, bone growth, and cellular differentiation. Renal synthesis of $1,25(OH)_2D$ from its endogenous precursor, 25-hydroxyvitamin D (25OHD), is the rate-limiting and is catalyzed by the $1{\alpha}$-hydroxylase. Vitamin D dependent rickets type I (VDDR-I), also referred to as vitamin D $1{\alpha}$-hydroxylase deficiency or pseudovitamin D deficiency rickets, is an autosomal recessive disorder characterized clinically by hypotonia, muscle weakness, growth failure, hypocalcemic seizures in early infancy, and radiographic findings of rickets. Characteristic laboratory features are hypocalcemia, increased serum concentrations of parathyroid hormone (PTH), and low or undetectable serum concentrations of $1,25(OH)_2D$ despite normal or increased concentrations of 25OHD. Recent advances have showed in the cloning of the human $1{\alpha}$-hydroxylase and revealed mutations in its gene that cause VDDR-I. This review presents the biology of vitamin D, and $1{\alpha}$-hydroxylase mutations with clinical findings.

• Journal of Genetic Medicine
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• v.19 no.1
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• pp.27-31
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• 2022

X-linked dominant hypophosphatemic rickets are the most common form of familial hypophosphatemic rickets resulting from hypophosphatemia caused by renal phosphate wasting, which in turn is a result of loss-of-function mutations in PHEX. Herein, we report a 39-year-old female with short stature and skeletal deformities and 12-month-old asymptomatic daughter. The female has a history of multiple surgical treatments because of lower limb deformities. Her biochemical findings revealed low serum phosphorus levels with elevated serum alkaline phosphatase activity and normal serum calcium levels, suggesting presence of hypophosphatemic rickets. To identify the molecular causes, we used a multigene testing panel and found a mutation, c.667dup (p.Asp223GlyfsTer15), in PHEX gene. To the best of our knowledge, this is a novel mutation. A heterozygous form of the same variant was detected in daughter, who showed no typical symptoms such as bow legs, frontal bossing, or waddling gate, but presented early signs of impaired mineralization in both X-ray and biochemical findings. The daughter was initiated onto early medical treatment with oral phosphate supplementation and an active vitamin D analog. Because the daughter was genetically diagnosed based on a family history before the onset of symptoms, appropriate medical management was possible from early infancy.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.108-112
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• 2000

Hypophosphatemic rickets is lack of reponse to physiologic doses of vitamin D, different from the vitamin D-dependent rickets. It is inherited in an X-linked dominant fashion. The prime features of this disorder are lowered serum phosphate levels, elevated serum alkaline phosphatase and normal serum calcium levels. The dental manifestation often include apical radiolucencies, abscess and fistulas of clinically sound teeth. Dental radiographs show ricketic bone trabeculations, abscent or abnormal lamina dura and abnormal cementum. This case which was diagnosed to hypophosphatemic rickets, showed multiple spontaneous periapical abscess and gingival fistula enlarged pulp chambers, extension of the pulp horns into the cusp tips and delayed eruption.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.152-157
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• 2010

Purpose : Vitamin D deficiency rickets is a significant public health problem that results from insufficient exposure to sunlight and inadequate vitamin D supplementation. The purpose of this study is to identify the clinical characteristics of vitamin D deficiency rickets in infants. Methods : Data of 35 infants diagnosed as vitamin D deficiency rickets at Sanggye-Paik Hospital, Seoul, Korea, from March 2007 to May 2009 were reviewed. Children with plasma 25-hydroxyvitamin D levels <15 ng/mL and 15-30 ng/mL were considered to have vitamin D deficiency and vitamin D insufficiency, respectively. Results : Thirty-five infants (22 boys, 13 girls) were diagnosed with rickets. Mean age at diagnosis was $7.4{\pm}7.1$ months (range: 0.1-29.8 months). Eighteen infants (51%) were vitamin D deficient and seventeen infants (49%) were insufficient. Twenty-eight of all (80%) diagnosed as subclinical rickets. Twenty-nine infants (83%) were below the age of 12months. Twenty infants (57%) had breastfed and ten infants (29%) had iron deficiency anemia. Nine of breastfed infants (45%) were vitamin D deficient and ten of their mothers were vitamin D insufficient. Overall, radiographic evidence of rickets was present in 93% of the cases. Radiographic sign of rickets was evident even in vitamin D insufficient state. Conclusion : It is important for the clinician to screen for subclinical vitamin D deficiency rickets in inadequately supplemented infants by pairing 25-hydroxyvitamin D levels with wrist radiographs. A nationwide epidemiological study of vitamin D deficiency rickets must be conducted and evidence-based national guidelines must be defined to prevent rickets.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.298-304
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• 2009

XLH (X-linked hypophosphatemic rickets) is a form of rickets which is resistant to the usual dose of vitamin D and inherited in a X-linked dominant manner. It is also known as vitamin D-resistant rickets or familial hypophosphatemic rickets. Here we report a 6-year-and-6-month-old female patient of XLH who is diagnosed with in SNUB. She was referred from local clinic for impaction of maxillary left permanent incisor and its treatment. She presents bowing deformities of the legs, short stature, enlargement of wrist and ankles and spontaneous dental abscesses of clinically sound teeth delayed eruption, taurodontism, delayed apical closure, enlarged pulp chambers, and absent or poorly defined lamina dura. The purpose of this case is to review the literatures of XLH and report the dental and medical characteristics of this patient.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.263-268
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• 2005

Epidermal nevus syndrome is a rare disease consisting of epidermal nevus and multisystem pathologic conditions associated with anomalies in the central nervous system, bone, eye, heart, vasculature and genito-urinary system. Hypophosphatemic rickets has been rarely observed in association with this syndrome. We report a case of hypophosphatemic rickets as sociated with epidermal nevus syndrome with review of the literature. (J Korean Soc Pediatr Nephrol 2005;9:263-268)