Renal calculus is a common disease with complex etiology and high recurrence rate. Recent studies have revealed that gene mutations may lead to metabolic defects which are associated with the formation of renal calculus, and single gene mutation is involved in relative high proportion of renal calculus. Gene mutations cause changes in enzyme function, metabolic pathway, ion transport, and receptor sensitivity, causing defects in oxalic acid metabolism, cystine metabolism, calcium ion metabolism, or purine metabolism, which may lead to the formation of renal calculus. The hereditary conditions associated with renal calculus include primary hyperoxaluria, cystinuria, Dent disease, familial hypomagnesemia with hypercalciuria and nephrocalcinosis, Bartter syndrome, primary distal renal tubular acidosis, infant hypercalcemia, hereditary hypophosphatemic rickets with hypercalciuria, adenine phosphoribosyltransferase deficiency, hypoxanthine-guanine phosphoribosyltransferase deficiency, and hereditary xanthinuria. This article reviews the research progress on renal calculus associated with inborn error of metabolism, to provide reference for early screening, diagnosis, treatment, prevention and recurrence of renal calculus.
Infant ; Humans ; Hypercalciuria/genetics* ; Kidney Calculi/genetics* ; Urolithiasis/genetics* ; Nephrocalcinosis/genetics* ; Metabolism, Inborn Errors/genetics*

Idiopathic infantile hypercalcemia is characterized by hypercalcemia, dehydration, vomiting, and failure to thrive, and it is due to mutations in 24-hydroxylase (CYP24A1). Recently, mutations in sodium-phosphate cotransporter (SLC34A1) expressed in the kidney were discovered as an additional cause of idiopathic infantile hypercalcemia. This report describes a female infant admitted for evaluation of nephrocalcinosis. She presented with hypercalcemia, hypercalciuria, low intact parathyroid hormone level, and high 1,25-dihydroxyvitamin D3 level. Exome sequencing identified novel compound heterozygous mutations in SLC34A1 (c.1337G>A, c.1483C>T). The patient was treated with fluids for hydration, furosemide, a corticosteroid, and restriction of calcium/vitamin D intake. At the age of 7 months, the patient's calcium level was within the normal range, and hypercalciuria waxed and waned. Renal echogenicity improved on the follow-up ultrasonogram, and developmental delay was not noted. In cases of hypercalcemia with subsequent hypercalciuria, DNA analysis for SLC34A1 gene mutations and CYP24A1 gene mutations should be performed. Further studies are required to obtain long-term data on hypercalciuria and nephrocalcinosis.
Calcitriol ; Calcium ; Dehydration ; DNA ; Exome ; Failure to Thrive ; Female ; Follow-Up Studies ; Furosemide ; Humans ; Hypercalcemia ; Hypercalciuria ; Hypophosphatemia ; Infant ; Kidney ; Nephrocalcinosis ; Parathyroid Hormone ; Reference Values ; Sodium-Phosphate Cotransporter Proteins ; Ultrasonography ; Vitamin D ; Vitamin D3 24-Hydroxylase ; Vomiting

Severe hypercalcemia is rarely encountered in children, even though serum calcium concentrations above 15-16 mg/dL could be life-threatening. We present a patient having severe hypercalcemia and azotemia. A 14-year-old boy with no significant past medical history was referred to our hospital with hypercalcemia and azotemia. Laboratory and imaging studies excluded hyperparathyroidism and solid tumor. Other laboratory findings including a peripheral blood profile were unremarkable. His hypercalcemia was not improved with massive hydration, diuretics, or even hemodialysis, but noticeably reversed with administration of calcitonin. A bone marrow biopsy performed to rule out the possibility of hematological malignancy revealed acute lymphoblastic leukemia. His hypercalcemia and azotemia resolved shortly after initiation of induction chemotherapy. Results in this patient indicate that a hematological malignancy could present with severe hypercalcemia even though blast cells have not appeared in the peripheral blood. Therefore, extensive evaluation to determine the cause of hypercalcemia is necessary. Additionally, appropriate treatment, viz., hydration or administration of calcitonin is important to prevent complications of severe hypercalcemia, including renal failure and nephrocalcinosis.
Acute Kidney Injury* ; Adolescent ; Azotemia ; Biopsy ; Bone Marrow ; Calcitonin ; Calcium ; Child ; Diuretics ; Hematologic Neoplasms ; Humans ; Hypercalcemia* ; Hyperparathyroidism ; Induction Chemotherapy ; Leukemia ; Male ; Nephrocalcinosis ; Precursor Cell Lymphoblastic Leukemia-Lymphoma* ; Renal Dialysis ; Renal Insufficiency

PURPOSE: Nephrocalcinosis (NC) is frequently observed in premature infants. Small-scale studies have suggested that NC adversely affects renal function; however, the etiologic factors are still unclear. This prospective observational study aimed to identify the factors that influence the development of NC, through urine analysis. METHODS: In total, 99 preterm infants (gestational age <34 weeks) diagnosed with NC in the neonatal intensive care unit (NICU) from October 2010 to March 2014 were evaluated. Data regarding perinatal characteristics, respiratory support, total parenteral nutrition (TPN), and use of nephrotoxic drugs were analyzed. After an ultrasonographic diagnosis of NC, the infants were subjected to biweekly urine tests along with ultrasonographic follow-ups until the resolution of NC, in the outpatient department. RESULTS: NC was diagnosed in 23% (99/432) of the preterm infants admitted to the NICU. Their median gestational age and birth weight were 28?³ (range:23??-35?²) weeks and 1,120 (range: 560-1,950) g, respectively. NC was diagnosed an average of 26.4±2.8 (range: 2-82) days after birth, and the corrected gestational age at that time was 32.4±2.0 weeks. Preterm infants with NC had hyperoxaluria (oxalate/Cr=4.1 [oxalate/Cr<0.3]), and low urinary citrate levels (citrate/Cr=0.03 [citrate/Cr>0.51]). The follow-up rate was 52% (27/52) and symptoms in none of the infants had progressed to nephrolithiasis. In the infants that were followed up, NC was resolved at a mean age of 7.7 (range: 2-32) months. CONCLUSION: Our results suggest that hyperoxaluria is a significant risk factor for the development of NC.
Birth Weight ; Citric Acid ; Diagnosis ; Follow-Up Studies ; Gestational Age ; Humans ; Hyperoxaluria ; Infant ; Infant, Newborn* ; Infant, Premature ; Intensive Care, Neonatal ; Korea* ; Nephrocalcinosis* ; Nephrolithiasis ; Observational Study ; Outpatients ; Parenteral Nutrition, Total ; Parturition ; Prognosis* ; Prospective Studies ; Risk Factors

Bartter syndrome (BS) is an inherited renal tubular disorder characterized by low or normal blood pressure, hypokalemic metabolic alkalosis, and hyperreninemic hyperaldosteronism. Type III BS is caused by loss-of-function mutations in CLCNKB encoding basolateral ClC-Kb. The clinical phenotype of patients with CLCNKB mutations has been known to be highly variable, and cases that are difficult to categorize as type III BS or other hereditary tubulopathies, such as Gitelman syndrome, have been rarely reported. We report a case of a 10-year-old Korean boy with atypical clinical findings caused by a novel CLCNKB mutation. The boy showed intermittent muscle cramps with laboratory findings of hypokalemia, severe hypomagnesemia, and nephrocalcinosis. These findings were not fully compatible with those observed in cases of BS or Gitelman syndrome. The CLCNKB mutation analysis revealed a heterozygous c.139G>A transition in exon 13 [p.Gly(GGG)465Glu(GAG)]. This change is not a known mutation; however, the clinical findings and in silico prediction results indicated that it is the underlying cause of his presentation.
Alkalosis ; Bartter Syndrome ; Blood Pressure ; Child ; Computer Simulation ; Exons ; Gitelman Syndrome ; Humans ; Hyperaldosteronism ; Hypokalemia ; Male ; Muscle Cramp ; Nephrocalcinosis ; Phenotype*

Renal tubular acidosis (RTA) is a syndrome characterized by hyperchloremic metabolic acidosis and an inability to excrete highly acid urine, in which the impaired acid excretion is disproportional to the reduction in the glomerular filtration rate. Distal renal tubular acidosis (dRTA) is frequently associated with immune-mediated disease, including Sjogren's syndrome. Sjogren's syndrome is a systemic autoimmune disease that mainly affects exocrine glands, such as the lacrimal and salivary glands, resulting in xerophthalmia and xerostomia. Extraglandular manifestations are frequent and may include renal involvement. Recently, we experienced two cases of renal tubular acidosis in patients with Sjogren's syndrome. The first patient had lower extremity weakness and hypokalemia and the second had nephrocalcinosis. We discuss the frequency and pathogenesis of dRTA in Sjogren's syndrome.
Acidosis ; Acidosis, Renal Tubular* ; Autoimmune Diseases ; Exocrine Glands ; Glomerular Filtration Rate ; Humans ; Hypokalemia ; Lower Extremity ; Nephrocalcinosis ; Salivary Glands ; Sjogren's Syndrome* ; Xerophthalmia ; Xerostomia

Vitamin D hydroxylation-deficient rickets type 1A (VDDR1A) is an autosomal recessively-inherited disorder caused by mutations in CYP27B1 encoding the 1α-hydroxylase enzyme. We report on a female patient with VDDR1A who presented with hypocalcemic seizure at the age of 13 months. The typical clinical and biochemical features of VDDR1A were found, such as hypocalcemia, increased alkaline phosphatase, secondary hyperparathyroidism and normal 25-hydroxyvitamin D3 (25(OH)D₃). Radiographic images of the wrist showed metaphyseal widening with cupping and fraying of the ulna and distal radius, suggesting rickets. A mutation analysis of the CYP27B1 gene identified a homozygous mutation of c.589+1G>A in the splice donor site in intron 3, which was known to be pathogenic. Since that time, the patient has been under calcitriol and calcium treatment, with normal growth and development. During the follow-up period, she did not develop genu valgum, scoliosis, or nephrocalcinosis.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase* ; Alkaline Phosphatase ; Calcifediol ; Calcitriol ; Calcium ; Female ; Follow-Up Studies ; Genu Valgum ; Growth and Development ; Humans ; Hyperparathyroidism, Secondary ; Hypocalcemia ; Introns ; Nephrocalcinosis ; Radius ; Rickets* ; RNA Splice Sites ; Scoliosis ; Seizures ; Ulna ; Vitamin D* ; Vitamins* ; Wrist

PURPOSE: The aim of this study was to determine the incidence, risk factors, and long-term outcome of nephrocalcinosis in very low birth weight (VLBW) infants. METHODS: A retrospective chart review was performed in VLBW infants between 2006 and 2012 in the neonatal intensive care unit. RESULTS: The incidence of nephrocalcinosis in VLBW infants was 10.2%. By univariate analysis, oligohydramnios and use of antenatal steroids were more frequent in the nephrocalcinosis group. In the nephrocalcinosis group, the gestational age and birth weight were lower and there were more number of female infants. Also, the initial blood pH, the lowest systolic blood pressure, and urine output on the first day of life were lower and bronchopulmonary dysplasia, sepsis, and urinary tract infection were more prevalent in the nephrocalcinosis group. The use of dexamethasone or ibuprofen and the lowest levels of phosphorus, protein and albumin were significantly lower in the nephrocalcinosis group. By binary logistic regression analysis, the use of antenatal steroids, female sex, 5-minute Apgar score, duration of oxygen therapy and total parenteral nutrition, and the lowest albumin level were found to be significant risk factors for nephrocalcinosis. Overall, the resolution rate was 64.1% and 88.6% within 12 months and 18 months, respectively. CONCLUSION: The incidence of nephrocalcinosis in VLBW infants showed increasing trend. The risk factors of nephrocalcinosis were parameters for sick VLBW infants. Although the prognosis of nephrocalcinosis was relatively good, we should pay close attention to the development of complication.
Apgar Score ; Birth Weight ; Blood Pressure ; Bronchopulmonary Dysplasia ; Dexamethasone ; Female ; Gestational Age ; Humans ; Hydrogen-Ion Concentration ; Ibuprofen ; Incidence ; Infant* ; Infant, Newborn ; Infant, Very Low Birth Weight* ; Intensive Care, Neonatal ; Logistic Models ; Nephrocalcinosis* ; Oligohydramnios ; Oxygen ; Parenteral Nutrition, Total ; Phosphorus ; Pregnancy ; Prognosis ; Retrospective Studies ; Risk Factors* ; Sepsis ; Steroids ; Urinary Tract Infections

Numerous cases of enamel renal syndrome have been previously reported. Various terms, such as enamel renal syndrome, amelogenesis imperfecta and gingival fibromatosis syndrome, and enamel-renal-gingival syndrome, have been used for patients presenting with the dental phenotype characteristic of this condition, nephrocalcinosis or nephrolithiasis, and gingival findings. This report describes a case of amelogenesis imperfecta of the enamel agenesis variety with nephrolithiasis in a 21-year-old male patient who complained of small teeth. The imaging modalities employed were conventional radiography, cone-beam computed tomography, and renal sonography. Such cases are first encountered by dentists, as other organ or metabolic diseases are generally hidden. Hence, cases of amelogenesis imperfecta should be subjected to advanced diagnostic modalities, incorporating both dental and medical criteria, in order to facilitate comprehensive long-term management.
Amelogenesis Imperfecta* ; Amelogenesis* ; Cone-Beam Computed Tomography ; Dental Enamel Hypoplasia ; Dental Enamel* ; Dentists ; Fibromatosis, Gingival ; Humans ; Kidney Diseases ; Male ; Metabolic Diseases ; Nephrocalcinosis ; Nephrolithiasis* ; Phenotype ; Radiography ; Tooth ; Young Adult

The calcium sensing receptor (CaSR) plays an important role in calcium homeostasis. Activating mutations of CaSR cause autosomal dominant hypocalcemia by affecting parathyroid hormone secretion in parathyroid gland and calcium resorption in kidney. They can also cause a type 5 Bartter syndrome by inhibiting the apical potassium channel in the thick ascending limb of the loop of Henle in the kidney. This study presents a patient who had autosomal dominant hypocalcemia with Bartter syndrome due to an activating mutation Y829C in the transmembrane domain of the CaSR. Symptoms of hypocalcemia occurred 12 days after birth and medication was started immediately. Medullary nephrocalcinosis and basal ganglia calcification were found at 7 years old and at 17 years old. Three hypercalcemic episodes occurred, one at 14 years old and two at 17 years old. The Bartter syndrome was not severe while the serum calcium concentration was controlled, but during hypercalcemic periods, the symptoms of Bartter syndrome were aggravated.
Bartter Syndrome* ; Basal Ganglia ; Calcium ; Extremities ; Homeostasis ; Humans ; Hypocalcemia* ; Kidney ; Loop of Henle ; Nephrocalcinosis ; Parathyroid Glands ; Parathyroid Hormone ; Parturition ; Potassium Channels ; Receptors, Calcium-Sensing*