1
|
Jacobsen C, Jüppner H, Mitchell DM. Case 21-2024: A 10-Month-Old Boy with Vomiting and Hypercalcemia. N Engl J Med 2024; 391:167-176. [PMID: 38986061 DOI: 10.1056/nejmcpc2402485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Affiliation(s)
- Christina Jacobsen
- From the Department of Pediatrics, Boston Children's Hospital (C.J.), the Department of Pediatrics, Massachusetts General Hospital (D.M.M., H.J.), and the Department of Pediatrics, Harvard Medical School (C.J., D.M.M., H.J.) - all in Boston
| | - Harald Jüppner
- From the Department of Pediatrics, Boston Children's Hospital (C.J.), the Department of Pediatrics, Massachusetts General Hospital (D.M.M., H.J.), and the Department of Pediatrics, Harvard Medical School (C.J., D.M.M., H.J.) - all in Boston
| | - Deborah M Mitchell
- From the Department of Pediatrics, Boston Children's Hospital (C.J.), the Department of Pediatrics, Massachusetts General Hospital (D.M.M., H.J.), and the Department of Pediatrics, Harvard Medical School (C.J., D.M.M., H.J.) - all in Boston
| |
Collapse
|
2
|
Jones G, Kaufmann M, St-Arnaud R. Infantile hypercalcemia type 1 (HCINF1): a rare disease resulting in nephrolithiasis and nephrocalcinosis caused by mutations in the vitamin D catabolic enzyme, CYP24A1. J Endocrinol Invest 2024:10.1007/s40618-024-02381-8. [PMID: 38780860 DOI: 10.1007/s40618-024-02381-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 04/21/2024] [Indexed: 05/25/2024]
Abstract
Infantile hypercalcemia type 1 (HCINF1), formerly known as Lightwood syndrome, is a subtype of hypercalcemia caused by loss-of-function biallelic mutations in the vitamin D catabolic enzyme, CYP24A1, which 24-hydroxylates the hormone 1,25-(OH)2D3. This short review focuses on the main features of the HCINF1 disease; emerging knowledge of the structure and function of the cytochrome P450, CYP24A1 and the location of inactivating mutations; the development of a rapid LC-MS/MS-based laboratory test for defective 24-hydroxylation; and future implications for bioanalytical assay and treatment of all types of vitamin D-related hypercalcemic conditions.
Collapse
Affiliation(s)
- G Jones
- Department of Biomedical & Molecular Sciences, Queen's University, Kingston, ON, Canada.
| | - M Kaufmann
- Department of Biomedical & Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - R St-Arnaud
- Shriners Hospitals for Children-Canada and McGill University, Montreal, QC, Canada
| |
Collapse
|
3
|
Leszczyńska D, Szatko A, Latocha J, Kochman M, Duchnowska M, Wójcicka A, Misiorowski W, Zgliczyníski W, Glinicki P. Persistent hypercalcaemia associated with two pathogenic variants in the CYP24A1 gene and a parathyroid adenoma-a case report and review. Front Endocrinol (Lausanne) 2024; 15:1355916. [PMID: 38665259 PMCID: PMC11043563 DOI: 10.3389/fendo.2024.1355916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
Introduction 24-Hydroxylase, encoded by the CYP24A1 gene, is a crucial enzyme involved in the catabolism of vitamin D. Loss-of-function mutations in CYP24A1 result in PTH-independent hypercalcaemia with high levels of 1,25(OH)2D3. The variety of clinical manifestations depends on age, and underlying genetic predisposition mutations can lead to fatal infantile hypercalcaemia among neonates, whereas adult symptoms are usually mild. Aim of the study We report a rare case of an adult with primary hyperparathyroidism and loss-of-function mutations in the CYP24A1 gene and a review of similar cases. Case presentation We report the case of a 58-year-old woman diagnosed initially with primary hyperparathyroidism. Preoperatively, the suspected mass adjoining the upper pole of the left lobe of the thyroid gland was found via ultrasonography and confirmed by 99mTc scintigraphy and biopsy as the parathyroid gland. The patient underwent parathyroidectomy (a histopathology report revealed parathyroid adenoma), which led to normocalcaemia. After 10 months, vitamin D supplementation was introduced due to deficiency, and the calcium level remained within the reference range. Two years later, biochemical tests showed recurrence of hypercalcaemia with suppressed parathyroid hormone levels and elevated 1,25(OH)2D3 concentrations. Further investigation excluded the most common causes of PTH-independent hypercalcaemia, such as granulomatous disease, malignancy, and vitamin D intoxication. Subsequently, vitamin D metabolites were measured using LC-MS/MS, which revealed high levels of 25(OH)D3, low levels of 24,25(OH)2D3 and elevated 25(OH)2D3/24,25(OH)2D3 ratios, suggesting a defect in vitamin D catabolism. Molecular analysis of the CYP24A1 gene using the NGS technique revealed two pathogenic variants: p.(Arg396Trp) and p.(Glu143del) (rs114368325 and rs777676129, respectively). Conclusions The diagnostic process for hypercalcaemia becomes complicated when multiple causes of hypercalcaemia coexist. The measurement of vitamin D metabolites using LC-MS/MS may help to identify carriers of CYP24A1 mutations. Subsequent molecular testing may contribute to establishing the exact frequency of pathogenic variants of the CYP24A1 gene and introducing personalized treatment.
Collapse
Affiliation(s)
- Dorota Leszczyńska
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Alicja Szatko
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
- EndoLab Laboratory, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Julia Latocha
- Students’ Scientific Group Affiliated with the Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Magdalena Kochman
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Maria Duchnowska
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Anna Wójcicka
- Warsaw Genomics, Warsaw, Poland
- Fundacja Wiedzieć Więcej, Warsaw, Poland
| | - Waldemar Misiorowski
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Wojciech Zgliczyníski
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
| | - Piotr Glinicki
- Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland
- EndoLab Laboratory, Centre of Postgraduate Medical Education, Warsaw, Poland
| |
Collapse
|
4
|
García-Castaño A, Madariaga L, Gómez-Conde S, González P, Grau G, Rica I, de Nanclares GP, De la Hoz AB, Aguayo A, Martínez R, Urrutia I, Gaztambide S, Castaño L. Genetic profile of a large Spanish cohort with hypercalcemia. Front Endocrinol (Lausanne) 2024; 15:1297614. [PMID: 38586466 PMCID: PMC10998451 DOI: 10.3389/fendo.2024.1297614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/27/2024] [Indexed: 04/09/2024] Open
Abstract
Introduction The disorders in the metabolism of calcium can present with manifestations that strongly suggest their diagnosis; however, most of the time, the symptoms with which they are expressed are nonspecific or present only as a laboratory finding, usually hypercalcemia. Because many of these disorders have a genetic etiology, in the present study, we sequenced a selection of 55 genes encoding the principal proteins involved in the regulation of calcium metabolism. Methods A cohort of 79 patients with hypercalcemia were analyzed by next-generation sequencing. Results The 30% of our cohort presented one pathogenic or likely pathogenic variant in genes associated with hypercalcemia. We confirmed the clinical diagnosis of 17 patients with hypocalciuric hypercalcemia (pathogenic or likely pathogenic variants in the CASR and AP2S1 genes), one patient with neonatal hyperparathyroidism (homozygous pathogenic variant in the CASR gene), and another patient with infantile hypercalcemia (two pathogenic variants in compound heterozygous state in the CYP24A1 gene). However, we also found variants in genes associated with primary hyperparathyroidism (GCM2), renal hypophosphatemia with or without rickets (SLC34A1, SLC34A3, SLC9A3R1, VDR, and CYP27B1), DiGeorge syndrome (TBX1 and NEBL), and hypophosphatasia (ALPL). Our genetic study revealed 11 novel variants. Conclusions Our study demonstrates the importance of genetic analysis through massive sequencing to obtain a clinical diagnosis of certainty. The identification of patients with a genetic cause is important for the appropriate treatment and identification of family members at risk of the disease.
Collapse
Affiliation(s)
- Alejandro García-Castaño
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Leire Madariaga
- Pediatric Nephrology Department, Biobizkaia Health Research Institute, Hospital Universitario Cruces, University of the Basque Country (UPV/EHU), CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Sara Gómez-Conde
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, University of the Basque Country (UPV/EHU), CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Pedro González
- Endocrinology and Nutrition Department, Biobizkaia Health Research Institute, Hospital Universitario Cruces, EndoERN, Barakaldo, Bizkaia, Spain
| | - Gema Grau
- Pediatric Endocrinology Department, Biobizkaia Health Research Institute, Hospital Universitario Cruces, EndoERN, Barakaldo, Bizkaia, Spain
| | - Itxaso Rica
- Pediatric Endocrinology Department, Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Gustavo Pérez de Nanclares
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Ana Belén De la Hoz
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Aníbal Aguayo
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Rosa Martínez
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Inés Urrutia
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | - Sonia Gaztambide
- Endocrinology and Nutrition Department, Biobizkaia Health Research Institute, Hospital Universitario Cruces, University of the Basque Country (UPV/EHU), CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| | | | - Luis Castaño
- Biobizkaia Health Research Institute, Hospital Universitario Cruces, University of the Basque Country (UPV/EHU), CIBERDEM, CIBERER, EndoERN, Barakaldo, Bizkaia, Spain
| |
Collapse
|
5
|
Wang Q, Chen JJ, Wei LY, Ding Y, Liu M, Li WJ, Su C, Gong CX. Biallelic and monoallelic pathogenic variants in CYP24A1 and SLC34A1 genes cause idiopathic infantile hypercalcemia. Orphanet J Rare Dis 2024; 19:126. [PMID: 38504242 PMCID: PMC10953066 DOI: 10.1186/s13023-024-03135-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 03/11/2024] [Indexed: 03/21/2024] Open
Abstract
OBJECTIVE Idiopathic infantile hypercalcemia (IIH) is a rare disorder of PTH-independent hypercalcemia. CYP24A1 and SLC34A1 gene mutations cause two forms of hereditary IIH. In this study, the clinical manifestations and molecular aspects of six new Chinese patients were investigated. METHODS The clinical manifestations and laboratory study of six patients with idiopathic infantile hypercalcemia were analyzed retrospectively. RESULTS Five of the patients were diagnosed with hypercalcemia, hypercalciuria, and bilateral medullary nephrocalcinosis. Their clinical symptoms and biochemical abnormalities improved after treatment. One patient presented at age 11 years old with arterial hypertension, hypercalciuria and nephrocalcinosis, but normal serum calcium. Gene analysis showed that two patients had compound heterozygous mutations of CYP24A1, one patient had a monoallelic CYP24A1 variant, and three patients had a monoallelic SLC34A1 variant. Four novel CYP24A1 variants (c.116G > C, c.287T > A, c.476G > A and c.1349T > C) and three novel SLC34A1 variants (c.1322 A > G, c.1697_1698insT and c.1726T > C) were found in these patients. CONCLUSIONS A monoallelic variant of CYP24A1 or SLC34A1 gene contributes to symptomatic hypercalcemia, hypercalciuria and nephrocalcinosis. Manifestations of IIH vary with onset age. Hypercalcemia may not necessarily present after infancy and IIH should be considered in patients with nephrolithiasis either in older children or adults.
Collapse
Affiliation(s)
- Qiao Wang
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Jia-Jia Chen
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Li-Ya Wei
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Yuan Ding
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Min Liu
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Wen-Jing Li
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Chang Su
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China
| | - Chun-Xiu Gong
- Department of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital, 56# Nan Lishi Road, west district, Beijing, 100045, China.
| |
Collapse
|
6
|
Mohan S, Sheehan M, Tebben P, Wermers R. Efficacy of Oral Cinacalcet in Non-PTH Nonmalignant Hypercalcemia from Excess 1,25-Dihydroxyvitamin D. JCEM CASE REPORTS 2024; 2:luae022. [PMID: 38476635 PMCID: PMC10928506 DOI: 10.1210/jcemcr/luae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Indexed: 03/14/2024]
Abstract
Elevated 1,25-dihydroxyvitamin D (1,25(OH)2D) is a rare cause of non-parathyroid hormone (PTH)-mediated hypercalcemia seen in granulomatous disease, malignancy (most often lymphoma), or genetic mutations. Therapeutic options are limited. We report the case of a 67-year-old White man with nonmalignant, nongranulomatous, 1,25(OH)2D-mediated hypercalcemia treated successfully with cinacalcet. At presentation, he had hypercalcemia, hypercalciuria with recurrent nephrolithiasis, low PTH, elevated 1,25(OH)2D, and normal 25-hydroxyvitamin D. The 1,25(OH)2D levels were inappropriate in the setting of hypercalcemia with low PTH. Evaluations for sarcoidosis, tuberculosis, and malignancy were negative. Genetic testing showed biallelic variants in the CYP24A1 gene. Cinacalcet was trialed and showed normalization of calcium levels. On cinacalcet, biochemical indices showed a slight increase in 1,25(OH)2D and 24-hour urine calcium and mild decrease in PTH. He briefly experienced symptomatic hypocalcemia that resolved after reducing cinacalcet dose. Due to limited symptomatic benefit, he opted to stop cinacalcet. Additional follow-up showed intermittently elevated serum calcium levels after stopping cinacalcet, most recently 10.3 mg/dL. Cinacalcet may be a therapeutic option in nonmalignant, 1,25(OH)2D-mediated hypercalcemia. Further study is necessary to confirm efficacy, understand risks and benefits, and elucidate mechanism(s) of action.
Collapse
Affiliation(s)
- Sneha Mohan
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition and Department of Medicine, Mayo College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Michael Sheehan
- Division of Endocrinology, Marshfield Clinic Health System, Weston Center, Weston, WI 54476, USA
| | - Peter Tebben
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition and Department of Medicine, Mayo College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
- Division of Pediatric Endocrinology and Department of Pediatric and Adolescent Medicine, Mayo College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Robert Wermers
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition and Department of Medicine, Mayo College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| |
Collapse
|
7
|
Brancatella A, Cappellani D, Pierotti L, Dinoi E, Sardella C, Borsari S, Piaggi P, Baldinotti F, Caligo MA, Marcocci C, Cetani F. When to suspect infantile hypercalcemia-1? J Endocrinol Invest 2024:10.1007/s40618-024-02312-7. [PMID: 38329607 DOI: 10.1007/s40618-024-02312-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 01/11/2024] [Indexed: 02/09/2024]
Abstract
PURPOSE The screening test to suspect infantile hypercalcemia-1 (HCINF1) is the measure of 25(OH)D3/24,25(OH)2D3 ratio at mass spectroscopy (MS). When the ratio is > 80, the gold standard for the diagnosis is genetic analysis. Given its limited availability, MS may not represent a screening test and most cases of HCINF1 remain undiagnosed. Aim of the study is to identify cut-offs of serum calcium and PTH useful to suspect patients with HCINF1. METHODS We compared the levels of total serum calcium and PTH of 6 patients with HCINF1 harboring biallelic CYP24A1 pathogenic variants with 3 different control groups: (1) 12 subjects wild type for CYP24A1; (2) 12 subjects matched for age and sex; (3) 12 subjects matched for vitamin D levels. We validated the cut-offs, testing the number of adult patients affected by HCINF1 reported in the literature that could be identified using these cut-offs. RESULTS A serum calcium level > 9.6 mg/dL showed the highest sensitivity (100%) and specificity (91%) in the comparison between homozygous and wild-type subjects. A serum PTH index < 0.315 showed the highest sensitivity (100%) and specificity (83.3%). A serum calcium level > 9.6 mg/dL was able to identify all adult HCINF1 patients whereas a PTH ratio < 0.315 identified 89.8% of the cases. Superimposable results were obtained using the other control groups. CONCLUSION Patients with serum calcium levels higher than 9.6 mg/dL and a PTH index lower than 0.315 are likely to be affected by HCINF1. Their diagnosis may be confirmed using MS and genetic analysis.
Collapse
Affiliation(s)
- A Brancatella
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - D Cappellani
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - L Pierotti
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - E Dinoi
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - C Sardella
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - S Borsari
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - P Piaggi
- Department of Information Engineering, University of Pisa, Pisa, Italy
| | - F Baldinotti
- Endocrine Unit 2, Laboratory of Molecular Genetics, University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
| | - M A Caligo
- Endocrine Unit 2, Laboratory of Molecular Genetics, University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
| | - C Marcocci
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - F Cetani
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy.
- Endocrine Unit, University Hospital of Pisa, Pisa, Italy.
| |
Collapse
|
8
|
Zheng Z, Wu Y, Wu H, Jin J, Luo Y, Cao S, Shan X. Clinical heterogeneity and therapeutic options for idiopathic infantile hypercalcemia caused by CYP24A1 pathogenic variant. J Pediatr Endocrinol Metab 2023; 36:999-1011. [PMID: 37768904 DOI: 10.1515/jpem-2023-0147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/12/2023] [Indexed: 09/30/2023]
Abstract
OBJECTIVES Infantile hypercalcemia-1 (HCINF1) is a rare disease caused by pathogenic variants in the CYP24A1 gene, resulting in the inability to metabolize active vitamin D. This leads to hypercalcemia and severe complications. CONTENT On December 8th, 2022, a systematic literature search was conducted in PubMed, Wanfang, and CNKI using the keywords "hypercalcemia" and "CYP24A1". Data extraction included patient demographics, clinical presentation, treatment medications, and outcomes. The findings were synthesized to identify common patterns and variations among cases and to assess the efficacy of different therapies in reducing serum calcium. Our findings revealed two distinct peaks in the incidence of HCINF1 caused by CYP24A1 pathogenic variant. Kidney stones or renal calcifications were the most common clinical manifestations of the disease, followed by polyuria and developmental delay. Laboratory investigations showed hypercalcemia, elevated vitamin D levels, hypercalciuria, and low parathyroid hormone. Genetic analysis remains the only reliable diagnostic tool. Although there is no definitive cure for HCINF1, multiple drugs, including bisphosphonates, calcitonin, and rifampicin, have been used to control its symptoms. Blocking the production and intake of vitamin D is the preferred treatment option. SUMMARY AND OUTLOOK Our review highlights the basic clinical and biochemical features of HCINF1 and suggests that targeted diagnostic and therapeutic strategies are needed to address the clinical heterogeneity of the disease. The insights gained from this study may facilitate the development of innovative treatments for HCINF1.
Collapse
Affiliation(s)
- Zhichao Zheng
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Yujie Wu
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Huiping Wu
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Jiahui Jin
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Yue Luo
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Shunshun Cao
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Xiaoou Shan
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| |
Collapse
|
9
|
Rodríguez AJ, Roberts DJ. Idiopathic infantile hypercalcaemia (IIH) resulting from a loss-of-function mutation in the CYP24A1 gene in a young high-performance athlete: A case report with a literature review of adult presentations. Clin Endocrinol (Oxf) 2023; 99:355-360. [PMID: 37501284 DOI: 10.1111/cen.14954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023]
Affiliation(s)
- Alexander J Rodríguez
- Bone and Muscle Health Research Group, Department of Medicine, School of Clinical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
- Department of Medicine (Endocrinology Division), Canberra Hospital, Canberra, Australia Capital Territory, Australia
| | - David J Roberts
- Department of Medicine, Logan Hospital (Metro South Health Service), Brisbane, Queensland, Australia
| |
Collapse
|
10
|
Collins L, Boehm E, Luxford C, Clifton‐Bligh R, Grill V. Hypervitaminosis D Secondary to a CYP24A1 Loss-of-Function Mutation: An Unusual Cause of Hypercalcemia in Two Siblings. JBMR Plus 2023; 7:e10788. [PMID: 37701149 PMCID: PMC10494500 DOI: 10.1002/jbm4.10788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 05/15/2023] [Accepted: 06/06/2023] [Indexed: 09/14/2023] Open
Abstract
Hypervitaminosis D as a cause of hypercalcemia may be due to vitamin D intoxication, granulomatous diseases, or abnormalities of vitamin D metabolism. The CYP24A1 gene encodes for the 24-hydroxylase enzyme, which is responsible for the catabolism of 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D). Mutations in CYP24A1 can result in elevated 1,25(OH)2D causing parathyroid hormone (PTH)-independent hypercalcemia, hypercalciuria, nephrolithiasis, and nephrocalcinosis. We present the cases of two siblings exhibiting hypercalcemia secondary to a CYP24A1 loss-of-function mutation. Case 1 presented initially with PTH-dependent hypercalcemia, with localization of a left upper parathyroid adenoma on parathyroid technetium sestamibi (99mTc-MIBI) uptake study. Despite parathyroidectomy (180 mg adenoma), hypercalcemia, hypercalciuria, and low normal PTH levels persisted. A repeat parathyroid 99mTc-MIBI uptake study localized a second adenoma and a right inferior parathyroidectomy was performed (170 mg adenoma). PTH subsequently became undetectable, however hypercalcemia and hypercalciuria persisted. A new presentation of PTH-independent hypercalcemia found to be secondary to a CYP24A1 loss-of-function mutation in his sibling, Case 2, signaled the underlying cause. Cascade testing confirmed both siblings were homozygous for the pathogenic variant c.1186C>T, p.Arg396Trp (R396W) of CYP24A1 (NM_000782.5). In clinical practice CYP24A1 loss-of-function mutations should be considered in patients presenting with PTH-independent hypercalcemia, hypercalciuria, and 1,25(OH)2D levels in the upper normal or elevated range. Although in our case assays of 24,25(OH)2D were not available, calculation of the 25(OH)D:24,25(OH)2D ratio can assist in the diagnostic process. Possible treatments to manage the risk of hypercalcemia in patients with a CYP24A1 loss-of-function mutation include avoidance of vitamin D oversupplementation and excessive sun exposure. Hydration and bisphosphonate therapy can be useful in managing the hypercalcemia. Although not utilized in our cases, treatment with ketoconazole, fluconazole, and rifampicin have been described as potential therapeutic options. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Lucy Collins
- Department of Endocrinology and DiabetesWestern HealthMelbourneVictoriaAustralia
| | - Emma Boehm
- Department of Endocrinology and DiabetesWestern HealthMelbourneVictoriaAustralia
- University of MelbourneMelbourneVictoriaAustralia
| | - Catherine Luxford
- Royal North Shore HospitalKolling InstituteSt LeonardsNew South WalesAustralia
| | - Roderick Clifton‐Bligh
- Royal North Shore HospitalKolling InstituteSt LeonardsNew South WalesAustralia
- Department of EndocrinologyRoyal North Shore HospitalSt LeonardsNew South WalesAustralia
| | - Vivian Grill
- Department of Endocrinology and DiabetesWestern HealthMelbourneVictoriaAustralia
- University of MelbourneMelbourneVictoriaAustralia
| |
Collapse
|
11
|
Wójcik M, Jaworski M, Płudowski P. 25(OH)D Concentration in Neonates, Infants, Toddlers, Older Children and Teenagers from Poland-Evaluation of Trends during Years 2014-2019. Nutrients 2023; 15:3477. [PMID: 37571414 PMCID: PMC10420956 DOI: 10.3390/nu15153477] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/13/2023] Open
Abstract
INTRODUCTION Local and international guidelines have provided schedules for the vitamin D supplementation of general populations of different ages, including children. Our study aimed to assess 25(OH)D concentration and its potential change during a growth and maturation period, adding parameters that reflect the risk of hypercalcemia. MATERIALS AND METHODS The available 25(OH)D concentration values (n = 17,636; 7.8 ± 6.0 years), calcium (n = 2673; 16.3 ± 6.1 years) and phosphate (n = 2830; 3.8 ± 5.2 years) metabolism markers were analyzed in a studied group of patients (0-18 years). RESULTS In the studied group the mean 25(OH)D concentration was 29.4 ± 11.7 ng/mL. Concentrations of 25(OH)D < 10 ng/mL were observed in 1.7% of patients (n = 292), 10-20 ng/mL in 17.2% (n = 3039), 20-30 ng/mL in 39.5% (n = 6960) and 30-50 ng/mL in 37.2% (n = 6567). In patients with a 25(OH)D concentration <10 ng/mL, normal calcemia (2.25-2.65 mmol/L) was observed in 29.5% of cases (n = 86). Three patients had 25(OH)D concentrations above 100 ng/mL with co-existing hypercalcemia; the mean was Ca = 3.40 mmol/L. Hypocalcemia (Ca < 2.25 mmol/L) was observed in 10,4% of patients (n = 2797). Furthermore, 5.0% of patients showed an increased calcium concentration >2.65 mmol/L (n = 1327). The highest mean 25(OH)D concentration of 32.1 ng/mL ± 12.9 was noted in the years 2018-2019 (n = 3931) and the lowest in the year 2015 (27.2 ng/mL ± 11.0; n = 2822). CONCLUSIONS Vitamin D deficiency (<20 ng/mL) was noted in 18,9% of subjects in the years 2014-2019. An effective prevention of vitamin D deficiency was observed in children aged 3 years and younger. A relationship between the concentrations of calcium and 25(OH)D was not observed.
Collapse
Affiliation(s)
| | | | - Paweł Płudowski
- Department of Biochemistry, Radioimmunology and Exerimental Medicine, The Children’s Memorial Health Institute, 04-730 Warsaw, Poland; (M.W.); (M.J.)
| |
Collapse
|
12
|
Kanemoto Y, Iwaki M, Sawada T, Nojiri K, Kurokawa T, Tsutsumi R, Nagasawa K, Kato S. Advances in the Administration of Vitamin D Analogues to Support Bone Health and Treat Chronic Diseases. J Bone Metab 2023; 30:219-229. [PMID: 37718900 PMCID: PMC10509026 DOI: 10.11005/jbm.2023.30.3.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/16/2023] [Indexed: 09/19/2023] Open
Abstract
Vitamin D (VD) exerts a wide variety of biological actions in addition to its well-known roles in calcium homeostasis. Nutritional VD deficiency induces rachitic abnormalities in growing children and osteomalacia in adults, and it has been proposed to underlie the onset and development of multiple non-communicable chronic diseases. Therefore, the administration of VD or synthetic VD analogues represents a promising therapeutic strategy; indeed, VD and a VD agonist have shown clinical promise in mitigating osteoporosis and symptoms of insufficient calcium intake. However, even though high doses of VD analogues have shown pre-clinical efficacy against several diseases, including cancers, they have not yet had wide-spread clinical success. This difference may be due to limitation of clinical doses in light of the inherent calcemic action of VD. An approach to overcome this problem involves the development of VD analogues with lower calcemic activity, which could be administered in high doses to attenuate the onset and progress of disease. In a similar strategy, selective estrogen receptor modulators have had success as anti-osteoporosis drugs, and they have shown benefit for other estrogen target organs by serving as partial antagonists or agonists of estrogen receptor α. It is thus conceivable to generate synthetic partial antagonists or agonists for the VD receptor (VDR) that would exert beneficial effects on bone and other VD target organs. In this review, we discuss the molecular basis of the development of such synthetic VDR ligands from the viewpoint of roles of VDR in gene regulation.
Collapse
Affiliation(s)
- Yoshiaki Kanemoto
- Graduate School of Life Science and Technology, Iryo Sosei University, Iwaki, Fukushima,
Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima,
Japan
| | - Miho Iwaki
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, Koganei, Tokyo,
Japan
| | - Takahiro Sawada
- Graduate School of Life Science and Technology, Iryo Sosei University, Iwaki, Fukushima,
Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima,
Japan
| | - Koki Nojiri
- Graduate School of Life Science and Technology, Iryo Sosei University, Iwaki, Fukushima,
Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima,
Japan
| | - Tomohiro Kurokawa
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima,
Japan
- School of Medicine, Fukushima Medical University, Fukushima, Fukushima,
Japan
| | - Rino Tsutsumi
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, Koganei, Tokyo,
Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, Koganei, Tokyo,
Japan
| | - Shigeaki Kato
- Graduate School of Life Science and Technology, Iryo Sosei University, Iwaki, Fukushima,
Japan
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima,
Japan
- School of Medicine, Fukushima Medical University, Fukushima, Fukushima,
Japan
| |
Collapse
|
13
|
Khan Z, Mlawa G, Yang YH, Mahamud B. A Case of Delayed Diagnosis of Idiopathic Infantile Hypercalcemia Due to CYP24A1 Mutation: A 10-Year Journey. Cureus 2023; 15:e42811. [PMID: 37664318 PMCID: PMC10470664 DOI: 10.7759/cureus.42811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2023] [Indexed: 09/05/2023] Open
Abstract
The parathyroid gland is responsible for the synthesis and secretion of parathyroid hormone, which is synthesized and released at an inverse relationship to the level of ionized calcium in the blood. Primary hyperparathyroidism affects women more than men. There are various causes for hyperparathyroidism-induced hypercalcemia and the most common cause is parathyroid adenoma. A less common cause of vitamin D-mediated parathyroid hormone-independent hypercalcemia is the loss of function mutation of the CYP24A1 gene. The CYP24A1 gene encodes the vitamin D 24-hydroxylase enzyme, responsible for hydroxylating the active form of vitamin D into an inactive form, and mutations in the CY24A1 gene can lead to elevated active vitamin D metabolite levels. It can result in hypercalcemia and hypercalciuria-related complications. We present a case of a 72-year-old male patient referred to the endocrine clinic, who had repeated treatments for hypercalcemia and recurrent renal calculi. He underwent ultrasound, computerized tomography, and sestamibi scans, all reported as normal. Following this, the patient underwent a positron emission tomography (PET) scan, which was also normal. He then finally underwent genetic testing and tested positive for the CYP24A1 gene. He was started on fluconazole 50mg once a day and cinacalcet 30mg twice with normalization of calcium level. Three of his family members also tested positive for the condition.
Collapse
Affiliation(s)
- Zahid Khan
- Acute Medicine, Mid and South Essex NHS Foundation Trust, Southend-on-Sea, GBR
- Cardiology, Barts Heart Centre, London, GBR
- Cardiology and General Medicine, Barking, Havering and Redbridge University Hospitals NHS Trust, London, GBR
- Cardiology, Royal Free Hospital, London, GBR
| | - Gideon Mlawa
- Internal Medicine and Diabetes and Endocrinology, Barking, Havering and Redbridge University Hospitals NHS Trust, London, GBR
| | - Yu-Hsuen Yang
- Acute and General Medicine, Barking, Havering and Redbridge University Hospitals NHS Trust, London, GBR
| | - Bashir Mahamud
- Internal Medicine and Diabetes and Endocrinology, Barking, Havering and Redbridge University Hospitals NHS Trust, London, GBR
| |
Collapse
|
14
|
Brunerova L, Remes O, Zoubkova V, Votypka P. Case report: Two heterozygous pathogenic variants of CYP24A1: A novel cause of hypercalcemia and nephrocalcinosis in adulthood. Front Med (Lausanne) 2023; 9:1020096. [PMID: 36703897 PMCID: PMC9871448 DOI: 10.3389/fmed.2022.1020096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
Background and aims Vitamin D 24-hydroxylase is an enzyme encoded by the CYP24A1 gene, which inhibits the activation of vitamin D to form inactive metabolites. More than 20 currently described pathogenic variants (usually biallelic) of this gene are responsible for idiopathic infantile hypercalcemia manifested typically in childhood (often in newborns) with hypercalcemia, hypercalciuria, and nephrocalcinosis. However, a few patients (mostly with monoallelic heterozygous pathogenic variants) can develop mild symptoms in adulthood. Case description We present the case of a 43-year-old male patient with hypertension and heterozygous Leiden mutation, with mural thrombi in the common iliac artery, who was sent by a nephrologist to endocrinological examination due to hypoparathyroidism, progressive hypercalcemia, hypercalciuria, and CKDG2A1. Complete laboratory and imaging methods (including PET-CT) excluded PTH-related peptide-mediated hypercalcemia and granulomatosis. Finally, the genetic analysis of the CYP24A1 gene revealed the presence of a novel combination of two heterozygous pathogenic variants: CYP24A1: c. 443T>C p.(Leu148Pro) and c.1186C>T p.(Arg396Trp). Conclusion Differential diagnosis of patients with hypercalciuria, nephrocalcinosis, and hypercalcemia related to vitamin D exposure should include the CYP24A1 gene mutation. To the best of our knowledge, this is the first case of the novel combination of two heterozygous pathogenic variants of CYP24A1.
Collapse
Affiliation(s)
- Ludmila Brunerova
- Department of Internal Medicine, Faculty Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Charles University, Prague, Czechia,*Correspondence: Ludmila Brunerova ✉
| | - Ondrej Remes
- Department of Internal Medicine, Faculty Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Charles University, Prague, Czechia,Nefromed, Prague, Czechia
| | - Veronika Zoubkova
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Pavel Votypka
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| |
Collapse
|
15
|
Abstract
IMPORTANCE Hypercalcemia affects approximately 1% of the worldwide population. Mild hypercalcemia, defined as total calcium of less than 12 mg/dL (<3 mmol/L) or ionized calcium of 5.6 to 8.0 mg/dL (1.4-2 mmol/L), is usually asymptomatic but may be associated with constitutional symptoms such as fatigue and constipation in approximately 20% of people. Hypercalcemia that is severe, defined as total calcium of 14 mg/dL or greater (>3.5 mmol/L) or ionized calcium of 10 mg/dL or greater (≥2.5 mmol/L) or that develops rapidly over days to weeks, can cause nausea, vomiting, dehydration, confusion, somnolence, and coma. OBSERVATIONS Approximately 90% of people with hypercalcemia have primary hyperparathyroidism (PHPT) or malignancy. Additional causes of hypercalcemia include granulomatous disease such as sarcoidosis, endocrinopathies such as thyroid disease, immobilization, genetic disorders, and medications such as thiazide diuretics and supplements such as calcium, vitamin D, or vitamin A. Hypercalcemia has been associated with sodium-glucose cotransporter 2 protein inhibitors, immune checkpoint inhibitors, denosumab discontinuation, SARS-CoV-2, ketogenic diets, and extreme exercise, but these account for less than 1% of causes. Serum intact parathyroid hormone (PTH), the most important initial test to evaluate hypercalcemia, distinguishes PTH-dependent from PTH-independent causes. In a patient with hypercalcemia, an elevated or normal PTH concentration is consistent with PHPT, while a suppressed PTH level (<20 pg/mL depending on assay) indicates another cause. Mild hypercalcemia usually does not need acute intervention. If due to PHPT, parathyroidectomy may be considered depending on age, serum calcium level, and kidney or skeletal involvement. In patients older than 50 years with serum calcium levels less than 1 mg above the upper normal limit and no evidence of skeletal or kidney disease, observation may be appropriate. Initial therapy of symptomatic or severe hypercalcemia consists of hydration and intravenous bisphosphonates, such as zoledronic acid or pamidronate. In patients with kidney failure, denosumab and dialysis may be indicated. Glucocorticoids may be used as primary treatment when hypercalcemia is due to excessive intestinal calcium absorption (vitamin D intoxication, granulomatous disorders, some lymphomas). Treatment reduces serum calcium and improves symptoms, at least transiently. The underlying cause of hypercalcemia should be identified and treated. The prognosis for asymptomatic PHPT is excellent with either medical or surgical management. Hypercalcemia of malignancy is associated with poor survival. CONCLUSIONS AND RELEVANCE Mild hypercalcemia is typically asymptomatic, while severe hypercalcemia is associated with nausea, vomiting, dehydration, confusion, somnolence, and coma. Asymptomatic hypercalcemia due to primary hyperparathyroidism is managed with parathyroidectomy or observation with monitoring, while severe hypercalcemia is typically treated with hydration and intravenous bisphosphonates.
Collapse
Affiliation(s)
- Marcella Donovan Walker
- Division of Endocrinology, Department of Medicine, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, New York, New York
| | - Elizabeth Shane
- Division of Endocrinology, Department of Medicine, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, New York, New York
| |
Collapse
|
16
|
Collins MT, Marcucci G, Anders HJ, Beltrami G, Cauley JA, Ebeling PR, Kumar R, Linglart A, Sangiorgi L, Towler DA, Weston R, Whyte MP, Brandi ML, Clarke B, Thakker RV. Skeletal and extraskeletal disorders of biomineralization. Nat Rev Endocrinol 2022; 18:473-489. [PMID: 35578027 DOI: 10.1038/s41574-022-00682-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/13/2022] [Indexed: 12/15/2022]
Abstract
The physiological process of biomineralization is complex and deviation from it leads to a variety of diseases. Progress in the past 10 years has enhanced understanding of the genetic, molecular and cellular pathophysiology underlying these disorders; sometimes, this knowledge has both facilitated restoration of health and clarified the very nature of biomineralization as it occurs in humans. In this Review, we consider the principal regulators of mineralization and crystallization, and how dysregulation of these processes can lead to human disease. The knowledge acquired to date and gaps still to be filled are highlighted. The disorders of mineralization discussed comprise a broad spectrum of conditions that encompass bone disorders associated with alterations of mineral quantity and quality, as well as disorders of extraskeletal mineralization (hyperphosphataemic familial tumoural calcinosis). Included are disorders of alkaline phosphatase (hypophosphatasia) and phosphate homeostasis (X-linked hypophosphataemic rickets, fluorosis, rickets and osteomalacia). Furthermore, crystallopathies are covered as well as arterial and renal calcification. This Review discusses the current knowledge of biomineralization derived from basic and clinical research and points to future studies that will lead to new therapeutic approaches for biomineralization disorders.
Collapse
Affiliation(s)
- Michael T Collins
- Skeletal Disorders and Mineral Homeostasis Section, National Institute of Dental and Craniofacial Research, NIH, Bethesda, MD, USA.
| | - Gemma Marcucci
- Bone Metabolic Diseases Unit, Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence, Italy
| | - Hans-Joachim Anders
- Department of Medicine IV, Hospital of the University of Munich, Ludwig-Maximilians University, Munich, Germany
| | - Giovanni Beltrami
- Department Paediatric Orthopedic Oncology, Careggi and Meyer Children Hospital, Florence, Italy
| | - Jane A Cauley
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter R Ebeling
- Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, Australia
| | - Rajiv Kumar
- Departments of Medicine, Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Agnès Linglart
- APHP, Endocrinologie et diabète de l'enfant, Paris, France
| | - Luca Sangiorgi
- Medical Genetics and Skeletal Rare Diseases, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Dwight A Towler
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ria Weston
- Cardiovascular Research Group, Manchester Metropolitan University, Manchester, UK
| | - Michael P Whyte
- Center for Metabolic Bone Disease and Molecular Research, Shriners Hospitals for Children-St Louis, St Louis, MO, USA
- Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, MO, USA
| | | | - Bart Clarke
- Mayo Clinic Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Rochester, MN, USA
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
17
|
Bertholet-Thomas A, Portefaix A, Flammier S, Dhelens C, Subtil F, Dubourg L, Laudy V, Le Bouar M, Boussaha I, Ndiaye M, Molin A, Lemoine S, Bacchetta J. Fluconazole in hypercalciuric patients with increased 1,25(OH) 2D levels: the prospective, randomized, placebo-controlled, double-blind FLUCOLITH trial. Trials 2022; 23:499. [PMID: 35710560 PMCID: PMC9204961 DOI: 10.1186/s13063-022-06302-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 04/13/2022] [Indexed: 11/23/2022] Open
Abstract
Background Hypercalciuria is one of the most frequent metabolic disorders associated with nephrolithiasis and/or nephrocalcinosis possibly leading to chronic kidney disease (CKD) and bone complications in adults. Orphan diseases with different underlying primary pathophysiology share inappropriately increased 1,25(OH)2D levels and hypercalciuria, e.g., hypersensitivity to vitamin D and renal phosphate wasting. Their management is challenging, typically based on hyperhydration and dietary advice. The antifungal azoles are known to inhibit the 1α-hydroxylase and therefore decrease 1,25(OH)2D levels; they are commonly used, with well described pharmacokinetic and tolerability data. Fluconazole has been successfully reported to reduce calciuria in patients with CYP24A1 or SLC34A3 mutations, with no safety warnings. Thus, based on these case reports, we hypothesize that fluconazole is effective to decrease and normalize calciuria in patients with hypercalciuria and increased 1,25(OH)2D levels. Methods The FLUCOLITH trial is a prospective, interventional, randomized in parallel groups (1:1), placebo-controlled, double-blind trial. A total of 60 patients (10–60 years) with nephrolithiasis and/or nephrocalcinosis history, hypercalciuria (> 0.1 mmol/kg/day), increased 1,25(OH)2D levels (> 150 pmol/L), and 25-OH-D levels >20 nmol/L will be included. Inclusions will be performed only from mid-September to the beginning of February to avoid bias due to sunlight-induced vitamin D synthesis. The primary endpoint will be the proportion of patients with normalization of 24-h calciuria between baseline and 16 weeks, or with a relative decrease of at least 30% of 24-h calciuria in patients who still display at W16 a 24-h hypercalciuria. Discussion The current challenge is to propose an efficient treatment to patients with hypercalciuria and increased 1,25(OH)2D levels in order to prevent later complications and notably CKD that can ultimately lead to end-stage renal disease. Based on improvement of knowledge in phosphate/calcium metabolism, pathophysiology and genetics, the “off-label” use of fluconazole was recently reported to be useful in hypercalciuric patients with increased 1,25(OH)2D levels. Thus, the FLUCOLITH study is a unique opportunity to develop a new indication of a well-known and not expensive drug in orphan renal diseases, the ultimate objective being the secondary prevention of CKD worsening in these patients. Trial registration ClinicalTrials.gov NCT04495608. Registered on July 23, 2020. Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-06302-z.
Collapse
Affiliation(s)
- Aurélia Bertholet-Thomas
- Centre de Référence des Maladies Rénales Rares, filières maladies rares ORKID and ERK-Net, Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Hôpital Femme Mère Enfant, Boulevard Pinel, 69677, Bron, Cedex, France.,Centre de Référence des Maladies Rares du Calcium et du Phosphate, filière maladies rares OSCAR, Hôpital Femme Mère Enfant, Bron, France.,INSERM 1033, Prévention des Maladies Osseuses, Lyon, France
| | - Aurélie Portefaix
- Centre d'Investigation Clinique, Hôpital Cardiovasculaire Louis Pradel, Inserm 1407, 69500, Bron, France
| | - Sacha Flammier
- Centre de Référence des Maladies Rénales Rares, filières maladies rares ORKID and ERK-Net, Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Hôpital Femme Mère Enfant, Boulevard Pinel, 69677, Bron, Cedex, France.,Centre de Référence des Maladies Rares du Calcium et du Phosphate, filière maladies rares OSCAR, Hôpital Femme Mère Enfant, Bron, France
| | - Carole Dhelens
- Pharmacie, FRIPHARM, Hôpital Edouard Herriot, Lyon, France
| | - Fabien Subtil
- Service de Biostatistique, Hospices Civils de Lyon, Lyon, France.,Université de Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive UMR 5558, Villeurbanne, France
| | - Laurence Dubourg
- Néphrologie, Dialyse, Hypertension Artérielle et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Lyon, France.,Faculté de Médecine Lyon Est, Université Lyon 1, Lyon, France
| | - Valérie Laudy
- Centre d'Investigation Clinique, Hôpital Cardiovasculaire Louis Pradel, Inserm 1407, 69500, Bron, France
| | - Myrtille Le Bouar
- Centre d'Investigation Clinique, Hôpital Cardiovasculaire Louis Pradel, Inserm 1407, 69500, Bron, France
| | - Inesse Boussaha
- Centre d'Investigation Clinique, Hôpital Cardiovasculaire Louis Pradel, Inserm 1407, 69500, Bron, France
| | - Marietou Ndiaye
- Centre d'Investigation Clinique, Hôpital Cardiovasculaire Louis Pradel, Inserm 1407, 69500, Bron, France
| | - Arnaud Molin
- Service de Génétique, CHU de Caen, Caen, France.,Centre de Référence des Maladies Rares du Calcium et du Phosphate, filière maladies rares OSCAR Caen, Caen, France
| | - Sandrine Lemoine
- Centre de Référence des Maladies Rénales Rares, filières maladies rares ORKID and ERK-Net, Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Hôpital Femme Mère Enfant, Boulevard Pinel, 69677, Bron, Cedex, France.,Centre de Référence des Maladies Rares du Calcium et du Phosphate, filière maladies rares OSCAR, Hôpital Femme Mère Enfant, Bron, France.,Néphrologie, Dialyse, Hypertension Artérielle et Exploration Fonctionnelle Rénale, Hôpital Edouard Herriot, Lyon, France.,Faculté de Médecine Lyon Est, Université Lyon 1, Lyon, France
| | - Justine Bacchetta
- Centre de Référence des Maladies Rénales Rares, filières maladies rares ORKID and ERK-Net, Service de Néphrologie, Rhumatologie et Dermatologie Pédiatriques, Hôpital Femme Mère Enfant, Boulevard Pinel, 69677, Bron, Cedex, France. .,Centre de Référence des Maladies Rares du Calcium et du Phosphate, filière maladies rares OSCAR, Hôpital Femme Mère Enfant, Bron, France. .,INSERM 1033, Prévention des Maladies Osseuses, Lyon, France. .,Faculté de Médecine Lyon Est, Université Lyon 1, Lyon, France.
| |
Collapse
|
18
|
Filler G, Schott C, Salerno FR, Ens A, McIntyre CW, Díaz González de Ferris ME, Stein R. Growth hormone therapy in HHRH. Bone Rep 2022; 16:101591. [PMID: 35663378 PMCID: PMC9156862 DOI: 10.1016/j.bonr.2022.101591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/08/2022] [Accepted: 05/16/2022] [Indexed: 01/20/2023] Open
Abstract
Background Hereditary Hypophosphatemic Rickets with Hypercalciuria (HHRH) (SLC34A3 gene, OMIM 241530) is an autosomal recessive disorder that results in a loss of function of the sodium-phosphate NPT2c channel at the proximal tubule. Phosphate supplementation rarely improves serum phosphate, hypercalciuria, nephrocalcinosis, 1,25(OH)2 vitamin D (1,25(OH)2D) levels or short stature. Methods We describe 23Na MRI and the successful use of recombinant human growth hormone (rhGH) and Fluconazole to improve growth (possibly confounded by puberty) and hypercalciuria in a now 12-year-old male with HHRH (novel homozygous SLC34A3 mutation, c.835_846 + 10del.T). Results The patient had chronic bone pain, hypophosphatemia (0.65 mmol/L[reference interval 1.1-1.9]), pathological fractures and medullary nephrocalcinosis/hypercalciuria (urinary calcium/creatinine ratio 1.66 mol/mmol[<0.6]). TmP/GFR was 0.65 mmol/L[0.97-1.64]; 1,25(OH)2D was >480 pmol/L[60-208]. Rickets Severity Score was 4. Treatment with 65 mg/kg/day of sodium phosphate and potassium citrate 10 mmol TID failed to correct the abnormalities.Adding rhGH at 0.35 mg/kg/week to the phosphate therapy, improved bone pain, height z-score from -2.09 to -1.42 over 6 months, without a sustained effect on TmP/GFR. Fluconazole was titrated to 100 mg once daily, resulting for the first time in a reduction of the 1,25(OH)2D to 462 and 426 pmol/L; serum phosphate 0.87 mmol/L, and calcium/creatinine ratio of 0.73.23Na MRI showed normal skin (z-score + 0.68) and triceps surae muscle (z-score + 1.5) Na+ levels; despite a defect in a sodium transporter, hence providing a rationale for a low sodium diet to improve hypercalciuria. Conclusions The addition of rhGH, Fluconazole and salt restriction to phosphate/potassium supplementation improved the conventional therapy. Larger studies are needed to confirm our findings.
Collapse
Affiliation(s)
- Guido Filler
- Departments of Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Pathology & Laboratory Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Lilibeth Caberto Kidney Clinical Research Unit, London, Ontario, Canada
| | - Clara Schott
- Medical Sciences, University of Western Ontario, Canada
| | - Fabio Rosario Salerno
- Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Lilibeth Caberto Kidney Clinical Research Unit, London, Ontario, Canada
| | - Andrea Ens
- Departments of Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Christopher William McIntyre
- Departments of Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Biophysics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
- Lilibeth Caberto Kidney Clinical Research Unit, London, Ontario, Canada
| | | | - Robert Stein
- Departments of Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| |
Collapse
|
19
|
Singh P, Harris PC, Sas DJ, Lieske JC. The genetics of kidney stone disease and nephrocalcinosis. Nat Rev Nephrol 2022; 18:224-240. [PMID: 34907378 DOI: 10.1038/s41581-021-00513-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2021] [Indexed: 12/15/2022]
Abstract
Kidney stones (also known as urinary stones or nephrolithiasis) are highly prevalent, affecting approximately 10% of adults worldwide, and the incidence of stone disease is increasing. Kidney stone formation results from an imbalance of inhibitors and promoters of crystallization, and calcium-containing calculi account for over 80% of stones. In most patients, the underlying aetiology is thought to be multifactorial, with environmental, dietary, hormonal and genetic components. The advent of high-throughput sequencing techniques has enabled a monogenic cause of kidney stones to be identified in up to 30% of children and 10% of adults who form stones, with ~35 different genes implicated. In addition, genome-wide association studies have implicated a series of genes involved in renal tubular handling of lithogenic substrates and of inhibitors of crystallization in stone disease in the general population. Such findings will likely lead to the identification of additional treatment targets involving underlying enzymatic or protein defects, including but not limited to those that alter urinary biochemistry.
Collapse
Affiliation(s)
- Prince Singh
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Division of Molecular Biology and Biochemistry, Mayo Clinic, Rochester, MN, USA
| | - David J Sas
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA.,Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA. .,Division of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA.
| |
Collapse
|
20
|
Rousseau-Nepton I, Jones G, Schlingmann K, Kaufmann M, Zuijdwijk CS, Khatchadourian K, Gupta IR, Pacaud D, Pinsk MN, Mokashi A, Nour MA, Alexander RT, Rodd CJ. CYP24A1 and SLC34A1 Pathogenic Variants Are Uncommon in a Canadian Cohort of Children with Hypercalcemia or Hypercalciuria. Horm Res Paediatr 2022; 94:124-132. [PMID: 34320495 DOI: 10.1159/000517548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/01/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Biallelic pathogenic variants in CYPA24A1 and SLC34A1 are causes of idiopathic infantile hypercalcemia. Pathogenic variants in both may also give rise to hypercalciuria with nephrocalcinosis or nephrolithiasis without previous hypercalcemia (renal group). Our objective was to examine the frequency of CYP24A1 or SLC34A1 variants in children with early hypercalcemia or late-onset hypercalciuria. METHOD Forty-one children from 7 centers across Canada were recruited. Local investigations were undertaken. The serum was evaluated by liquid chromatography tandem-mass spectrometry for the ratio of 25-hydroxyvitamin D3 to 24,25-dihydroxyvitamin D3, (25-OH-D3:24,25-(OH)2D3), an elevation pathognomonic for the loss of function of the CYP24A1 enzyme. Mutational analyses were undertaken. Family cascade screening was performed if pathogenic variants were detected in probands. RESULTS Twenty-nine children had early-onset hypercalcemia; none had elevated 25-OH-D3:24,25-(OH)2D3 or variants. Interestingly, 2 of 12 in the renal group had elevated 25-OH-D3:24,25-(OH)2D3 and presented as preadolescents. In case 1, cascade testing revealed a sibling and parent with asymptomatic pathogenic variants in CYP24A1. Four CYP24A1 pathogenic variants were identified in these 2 probands: 3 have been described in European populations, and 1 is a rare variant in exon 7 (c931delC) that is likely pathogenic. No SLC34A1 pathogenic variants were detected. CONCLUSION In Canada, pathogenic variants in CYP24A1 appear to manifest with late-onset hypercalciuria and its sequelae. The 25-OH-D3:24,25-(OH)2D3 ratio is an excellent tool for screening for biallelic pathogenic variants in CYP24A1. We confirm that cascade testing is important for these variants.
Collapse
Affiliation(s)
| | - Glenville Jones
- Department of Biomedical & Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Karlpiet Schlingmann
- Department of General Pediatrics, University Children's Hospital, University of Münster, Münster, Germany
| | - Martin Kaufmann
- Department of Biomedical & Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | | | | | - Indra R Gupta
- Department of Pediatrics, McGill University, Montreal, Québec, Canada
| | - Danièle Pacaud
- Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada
| | - Maury N Pinsk
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Arati Mokashi
- Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Munier A Nour
- Department of Pediatrics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - R Todd Alexander
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Celia J Rodd
- Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| |
Collapse
|
21
|
Hanna C, Potretzke TA, Chedid M, Rangel LJ, Arroyo J, Zubidat D, Tebben PJ, Cogal AG, Torres VE, Harris PC, Sas DJ, Lieske JC, Milliner DS, Chebib FT. Kidney Cysts in Hypophosphatemic Rickets With Hypercalciuria: A Case Series. Kidney Med 2022; 4:100419. [PMID: 35386604 PMCID: PMC8978140 DOI: 10.1016/j.xkme.2022.100419] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Rationale & Objective Study Design Setting & Participants Results Limitations Conclusions
Collapse
|
22
|
Calcium and Vitamin D Supplementation and Their Association with Kidney Stone Disease: A Narrative Review. Nutrients 2021; 13:nu13124363. [PMID: 34959915 PMCID: PMC8707627 DOI: 10.3390/nu13124363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 11/30/2021] [Accepted: 11/30/2021] [Indexed: 01/03/2023] Open
Abstract
Kidney stone disease is a multifactorial condition influenced by both genetic predisposition and environmental factors such as lifestyle and dietary habits. Although different monogenic polymorphisms have been proposed as playing a causal role for calcium nephrolithiasis, the prevalence of these mutations in the general population and their complete pathogenetic pathway is yet to be determined. General dietary advice for kidney stone formers includes elevated fluid intake, dietary restriction of sodium and animal proteins, avoidance of a low calcium diet, maintenance of a normal body mass index, and elevated intake of vegetables and fibers. Thus, balanced calcium consumption protects against the risk for kidney stones by reducing intestinal oxalate availability and its urinary excretion. However, calcium supplementation given between meals might increase urinary calcium excretion without the beneficial effect on oxalate. In kidney stone formers, circulating active vitamin D has been found to be increased, whereas higher plasma 25-hydroxycholecalciferol seems to be present only in hypercalciuric patients. The association between nutritional vitamin D supplements and the risk for stone formation is currently not completely understood. However, taken together, available evidence might suggest that vitamin D administration worsens the risk for stone formation in patients predisposed to hypercalciuria. In this review, we analyzed and discussed available literature on the effect of calcium and vitamin D supplementation on the risk for kidney stone formation.
Collapse
|
23
|
Abstract
Vitamin D metabolism represents a well-integrated, hormonally regulated endocrine unit interlinking calcium and phosphate metabolism. Pathophysiologic processes disturbing vitamin D metabolism comprise classic defects of vitamin D activation and action presenting as different forms of vitamin D-dependent rickets as well as disorders with increased vitamin D activity. The latter may result in hypercalcemia, hypercalciuria, and renal calcifications. Acquired and hereditary disorders causing hypervitaminosis D are discussed, including vitamin D intoxication, granulomatous disease, and idiopathic infantile hypercalcemia that may be caused by either a defective vitamin D degradation or by a primary defect in phosphate conservation.
Collapse
Affiliation(s)
- Karl Peter Schlingmann
- Department of General Pediatrics, University Children's Hospital, Albert-Schweitzer-Campus 1, Münster 48149, Germany.
| |
Collapse
|
24
|
Cogal AG, Arroyo J, Shah RJ, Reese KJ, Walton BN, Reynolds LM, Kennedy GN, Seide BM, Senum SR, Baum M, Erickson SB, Jagadeesh S, Soliman NA, Goldfarb DS, Beara-Lasic L, Edvardsson VO, Palsson R, Milliner DS, Sas DJ, Lieske JC, Harris PC. Comprehensive Genetic Analysis Reveals Complexity of Monogenic Urinary Stone Disease. Kidney Int Rep 2021; 6:2862-2884. [PMID: 34805638 PMCID: PMC8589729 DOI: 10.1016/j.ekir.2021.08.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/24/2021] [Accepted: 08/30/2021] [Indexed: 01/06/2023] Open
Abstract
Introduction Because of phenotypic overlap between monogenic urinary stone diseases (USD), gene-specific analyses can result in missed diagnoses. We used targeted next generation sequencing (tNGS), including known and candidate monogenic USD genes, to analyze suspected primary hyperoxaluria (PH) or Dent disease (DD) patients genetically unresolved (negative; N) after Sanger analysis of the known genes. Cohorts consisted of 285 PH (PHN) and 59 DD (DDN) families. Methods Variants were assessed using disease-specific and population databases plus variant assessment tools and categorized using the American College of Medical Genetics (ACMG) guidelines. Prior Sanger analysis identified 47 novel PH or DD gene pathogenic variants. Results Screening by tNGS revealed pathogenic variants in 14 known monogenic USD genes, accounting for 45 families (13.1%), 27 biallelic and 18 monoallelic, including 1 family with a copy number variant (CNV). Recurrent genes included the following: SLC34A3 (n = 13), CLDN16 (n = 8), CYP24A1 (n = 4), SLC34A1 (n = 3), SLC4A1 (n = 3), APRT (n = 2), CLDN19 (n = 2), HNF4A1 (n = 2), and KCNJ1 (n = 2), whereas ATP6V1B1, CASR, and SLC12A1 and missed CNVs in the PH genes AGXT and GRHPR accounted for 1 pedigree each. Of the 48 defined pathogenic variants, 27.1% were truncating and 39.6% were novel. Most patients were diagnosed before 18 years of age (76.1%), and 70.3% of biallelic patients were homozygous, mainly from consanguineous families. Conclusion Overall, in patients suspected of DD or PH, 23.9% and 7.3% of cases, respectively, were caused by pathogenic variants in other genes. This study shows the value of a tNGS screening approach to increase the diagnosis of monogenic USD, which can optimize therapies and facilitate enrollment in clinical trials.
Collapse
Affiliation(s)
- Andrea G Cogal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Jennifer Arroyo
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Ronak Jagdeep Shah
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Kalina J Reese
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Brenna N Walton
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Laura M Reynolds
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gabrielle N Kennedy
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | - Barbara M Seide
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Sarah R Senum
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Stephen B Erickson
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Neveen A Soliman
- Department of Pediatrics, Center of Pediatric Nephrology and Transplantation, Kasr Al Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - David S Goldfarb
- Nephrology Division, New York University Langone Health and New York University School of Medicine, New York, New York, USA
| | - Lada Beara-Lasic
- Nephrology Division, New York University Langone Health and New York University School of Medicine, New York, New York, USA
| | - Vidar O Edvardsson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Children's Medical Center, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
| | - Runolfur Palsson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland.,Division of Nephrology, Landspitali-The National University Hospital of Iceland, Reykjavik, Iceland
| | - Dawn S Milliner
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - David J Sas
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA
| | | |
Collapse
|
25
|
Lenherr-Taube N, Furman M, Assor E, Elia Y, Collins C, Thummel K, Levine MA, Sochett E. Mild Idiopathic Infantile Hypercalcemia-Part 2: A Longitudinal Observational Study. J Clin Endocrinol Metab 2021; 106:2938-2948. [PMID: 34139759 PMCID: PMC8475233 DOI: 10.1210/clinem/dgab432] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Indexed: 11/19/2022]
Abstract
CONTEXT Idiopathic infantile hypercalcemia (IIH) is an uncommon disorder with variable clinical features. The natural history and response to dietary calcium and vitamin D restriction in IIH remains unclear. OBJECTIVE The aim of this study is to describe the clinical and biochemical response to dietary calcium and vitamin D restriction in a genetically characterized cohort of mild IIH. METHODS This is a longitudinal, observational cohort study of 20 children with mild IIH monitored for a median of 21months. Biochemical measures, dietary assessment, and yearly renal ultrasound results, since the time of diagnosis, were obtained and assessed prospectively every 4 to 6 months. RESULTS Median age at initial diagnosis was 4.5 months. Median levels of serum calcium (2.82 mmol/L) and 1,25 (OH)2D (192 pmol/L) were elevated, whereas serum PTH was reduced (10 ng/L). Urinary calcium:creatinine ratio was elevated for some, but not all individuals (median 1.49 mmol/mmol). All patients who were managed with a low-calcium diet showed an improvement in serum and urinary calcium measures, but the serum concentration of 1,25 dihydroxyvitamin D (1,25(OH)2D) and 1,25(OH)2D/PTH ratio remained elevated. In 2 of the 11 subjects, renal calcification worsened. There were no differences in response between individuals with CYP24A1 or SLC34A1/A3 variants. CONCLUSION The clinical presentation of mild IIH is variable, and dietary calcium and vitamin D restriction does not consistently normalize elevated 1,25(OH)2D concentrations or prevent worsening of renal calcification in all cases. Therapeutic options should target the defect in vitamin D metabolism.
Collapse
Affiliation(s)
- Nina Lenherr-Taube
- Department of Pediatrics, Division of Endocrinology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Michelle Furman
- Department of Pediatrics, Division of Endocrinology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Esther Assor
- Department of Pediatrics, Division of Endocrinology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Yesmino Elia
- Department of Pediatrics, Division of Endocrinology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Carol Collins
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Kenneth Thummel
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Michael A Levine
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia and Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Etienne Sochett
- Department of Pediatrics, Division of Endocrinology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
26
|
Janiec A, Halat-Wolska P, Obrycki Ł, Ciara E, Wójcik M, Płudowski P, Wierzbicka A, Kowalska E, Książyk JB, Kułaga Z, Pronicka E, Litwin M. Long-term outcome of the survivors of infantile hypercalcaemia with CYP24A1 and SLC34A1 mutations. Nephrol Dial Transplant 2021; 36:1484-1492. [PMID: 33099630 PMCID: PMC8311581 DOI: 10.1093/ndt/gfaa178] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 05/25/2020] [Indexed: 11/12/2022] Open
Abstract
Background Infantile hypercalcaemia (IH) is a vitamin D3 metabolism disorder. The molecular basis for IH is biallelic mutations in the CYP24A1 or SLC34A1 gene. These changes lead to catabolism disorders (CYP24A1 mutations) or excessive generation of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] (SLC34A1 mutations). The incidence rate of IH in children and the risk level for developing end-stage renal disease (ESRD) are still unknown. The aim of this study was to analyse the long-term outcome of adolescents and young adults who suffered from IH in infancy. Design Forty-two children (23 girls; average age 10.7 ± 6.3 years) and 26 adults (14 women; average age 24.2 ± 4.4 years) with a personal history of hypercalcaemia with elevated 1,25(OH)2D3 levels were included in the analysis. In all patients, a genetic analysis of possible IH mutations was conducted, as well as laboratory tests and renal ultrasonography. Results IH was confirmed in 20 studied patients (10 females). CYP24A1 mutations were found in 16 patients (8 females) and SLC34A1 in 4 patients (2 females). The long-term outcome was assessed in 18 patients with an average age of 23.8 years (age range 2–34). The average glomerular filtration rate (GFR) was 72 mL/min/1.73 m2 (range 15–105). Two patients with a CYP24A1 mutation developed ESRD and underwent renal transplantation. A GFR <90 mL/min/1.73 m2 was found in 14 patients (77%), whereas a GFR <60 mL/min/1.73 m2 was seen in 5 patients (28%), including 2 adults after renal transplantation. Three of 18 patients still had serum calcium levels >2.6 mmol/L. A renal ultrasound revealed nephrocalcinosis in 16 of 18 (88%) patients, however, mild hypercalciuria was detected in only one subject. Conclusions Subjects who suffered from IH have a greater risk of progressive chronic kidney disease and nephrocalcinosis. This indicates that all survivors of IH should be closely monitored, with early implementation of preventive measures, e.g. inhibition of active metabolites of vitamin D3 synthesis.
Collapse
Affiliation(s)
- Agnieszka Janiec
- Department of Paediatrics, Nutrition and Metabolic Diseases, Children's Memorial Health Institute, Warsaw, Poland
| | - Paulina Halat-Wolska
- Department of Medical Genetics, Children's Memorial Health Institute, Warsaw, Poland
| | - Łukasz Obrycki
- Department of Nephrology, Kidney Transplantation and Arterial Hypertension, Children's Memorial Health Institute, Warsaw, Poland
| | - Elżbieta Ciara
- Department of Medical Genetics, Children's Memorial Health Institute, Warsaw, Poland
| | - Marek Wójcik
- Department of Biochemistry, Radioimmunology and Experimental Medicine, Children's Memorial Health Institute, Warsaw, Poland
| | - Paweł Płudowski
- Department of Biochemistry, Radioimmunology and Experimental Medicine, Children's Memorial Health Institute, Warsaw, Poland
| | - Aldona Wierzbicka
- Department of Biochemistry, Radioimmunology and Experimental Medicine, Children's Memorial Health Institute, Warsaw, Poland
| | - Ewa Kowalska
- Department of Biochemistry, Radioimmunology and Experimental Medicine, Children's Memorial Health Institute, Warsaw, Poland
| | - Janusz B Książyk
- Department of Paediatrics, Nutrition and Metabolic Diseases, Children's Memorial Health Institute, Warsaw, Poland
| | - Zbigniew Kułaga
- Department of Public Health, Children's Memorial Health Institute, Warsaw, Poland
| | - Ewa Pronicka
- Department of Paediatrics, Nutrition and Metabolic Diseases, Children's Memorial Health Institute, Warsaw, Poland.,Department of Medical Genetics, Children's Memorial Health Institute, Warsaw, Poland
| | - Mieczysław Litwin
- Department of Nephrology, Kidney Transplantation and Arterial Hypertension, Children's Memorial Health Institute, Warsaw, Poland
| |
Collapse
|
27
|
Azer SM, Vaughan LE, Tebben PJ, Sas DJ. 24-Hydroxylase Deficiency Due to CYP24A1 Sequence Variants: Comparison With Other Vitamin D-mediated Hypercalcemia Disorders. J Endocr Soc 2021; 5:bvab119. [PMID: 34337279 PMCID: PMC8317629 DOI: 10.1210/jendso/bvab119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Indexed: 11/26/2022] Open
Abstract
Context CYP24A1 encodes 24-hydroxylase, which converts 25(OH)D3 and 1,25(OH)2D3 to inactive metabolites. Loss-of-function variants in CYP24A1 are associated with 24-hydroxylase deficiency (24HD), characterized by hypercalcemia, nephrolithiasis, and nephrocalcinosis. We retrospectively reviewed laboratory, imaging, and clinical characteristics of patients with suspected or confirmed 24HD and patients with other vitamin D−mediated hypercalcemia disorders: sarcoidosis, lymphoma, and exogenous vitamin D toxicity (EVT). Objective To identify features that differentiate 24HD from other vitamin D-mediated hypercalcemia disorders. Methods Patients seen at the Mayo Clinic (Rochester, MN) from January 1, 2008, to 31 December, 2016, with the following criteria were retrospectively identified: serum calcium ≥9.6 mg/dL, parathyroid hormone <30 pg/mL, and 1,25(OH)2D3 >40 pg/mL. Patients were considered to have 24HD if they had (1) confirmed CYP24A1 gene variant or (2) 25(OH)D3:24,25(OH)2D ratio ≥50. Patients with sarcoidosis, lymphoma, and EVT were also identified. Groups were compared using the Fisher exact test (categorical variables) or the Wilcoxon rank sum test (continuous variables). Results We identified 9 patients with 24HD and 28 with other vitamin D−mediated disorders. Patients with 24HD were younger at symptom onset (median 14 vs 63 years; P = .001) and had positive family history (88.9% vs 20.8%; P < .001), nephrocalcinosis (88.9% vs 6.3%; P < .001), lower lumbar spine Z-scores (median −0.50 vs 1.20; P = .01), higher peak serum phosphorus (% of peak reference range, median 107 vs 84; P = .01), and higher urinary calcium:creatinine ratios (median 0.24 vs 0.17; P = .047). Conclusion Patients with 24HD had clinical and laboratory findings that differed from other vitamin D−mediated hypercalcemia disorders. 24HD should be suspected in patients with hypercalcemia who present at younger age, have positive family history, and have nephrocalcinosis.
Collapse
Affiliation(s)
- Sarah M Azer
- Mayo Clinic Alix School of Medicine-Minnesota Campus, Rochester, MN 55905, USA
| | - Lisa E Vaughan
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN 55905, USA
| | - Peter J Tebben
- Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, MN 55905, USA.,Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - David J Sas
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN 55905, USA.,Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN 55905, USA
| |
Collapse
|
28
|
Hanna C, Potretzke TA, Cogal AG, Mkhaimer YG, Tebben PJ, Torres VE, Lieske JC, Harris PC, Sas DJ, Milliner DS, Chebib FT. High Prevalence of Kidney Cysts in Patients With CYP24A1 Deficiency. Kidney Int Rep 2021; 6:1895-1903. [PMID: 34307984 PMCID: PMC8258502 DOI: 10.1016/j.ekir.2021.04.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/20/2021] [Accepted: 04/26/2021] [Indexed: 12/17/2022] Open
Abstract
Introduction Loss-of-function variants in the CYP24A1 gene cause a rare hereditary disease characterized by reduced 24-hydroxylase enzyme activity, increased serum 1,25-dihydroxycholecalciferol levels, hypercalcemia, hypercalciuria, and nephrocalcinosis and/or nephrolithiasis. Kidney cysts in patients with CYP24A1 deficiency were first reported in a single case study from our center. However, a possible association between CYP24A1 deficiency and kidney cysts has not been described. Methods Retrospective analysis of patients with confirmed or suspected CYP24A1 deficiency and available kidney imaging. Results Among 16 patients with confirmed pathogenic variants, 38% were male and 31% were children, the median age at genetic confirmation was 38 years (range 1–66), and none had a family history of cystic kidney disease. Medullary and/or corticomedullary junction cysts were present in all cases. The median age at first detected cyst was 37 years (range 3–60). The mean and median number of cysts per patient were 5.3 and 2.5 (range 1–37), respectively. Four of 5 further patients with suspected but unconfirmed pathogenic variants had cysts. The number of cysts ≥5 mm in size was above the 97.5th percentile of an age- and sex-matched control population in 55% and 67% of patients with confirmed and suspected pathogenic variants, respectively. At least 1 cyst (≥5 mm in size) was found in 80% of children with confirmed CYP24A1 deficiency. Conclusions These observations strongly suggest an association between CYP24A1 deficiency and kidney cysts. Further studies are needed to evaluate the role of CYP24A1, vitamin D metabolism, and/or hypercalciuria in cyst formation, and whether cysts exacerbate chronic kidney disease or modify nephrocalcinosis and stone risk.
Collapse
Affiliation(s)
- Christian Hanna
- Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Andrea G Cogal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Yaman G Mkhaimer
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter J Tebben
- Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - John C Lieske
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - David J Sas
- Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Dawn S Milliner
- Division of Pediatric Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA.,Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Fouad T Chebib
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| |
Collapse
|
29
|
Makris K, Bhattoa HP, Cavalier E, Phinney K, Sempos CT, Ulmer CZ, Vasikaran SD, Vesper H, Heijboer AC. Recommendations on the measurement and the clinical use of vitamin D metabolites and vitamin D binding protein - A position paper from the IFCC Committee on bone metabolism. Clin Chim Acta 2021; 517:171-197. [PMID: 33713690 DOI: 10.1016/j.cca.2021.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/10/2021] [Accepted: 03/04/2021] [Indexed: 02/08/2023]
Abstract
Vitamin D, an important hormone with a central role in calcium and phosphate homeostasis, is required for bone and muscle development as well as preservation of musculoskeletal function. The most abundant vitamin D metabolite is 25-hydroxyvitamin D [25(OH)D], which is currently considered the best marker to evaluate overall vitamin D status. 25(OH)D is therefore the most commonly measured metabolite in clinical practice. However, several other metabolites, although not broadly measured, are useful in certain clinical situations. Vitamin D and all its metabolites are circulating in blood bound to vitamin D binding protein, (VDBP). This highly polymorphic protein is not only the major transport protein which, along with albumin, binds over 99% of the circulating vitamin D metabolites, but also participates in the transport of the 25(OH)D into the cell via a megalin/cubilin complex. The accurate measurement of 25(OH)D has proved a difficult task. Although a reference method and standardization program are available for 25(OH)D, the other vitamin D metabolites still lack this. Interpretation of results, creation of clinical supplementation, and generation of therapeutic guidelines require not only accurate measurements of vitamin D metabolites, but also the accurate measurements of several other "molecules" related with bone metabolism. IFCC understood this priority and a committee has been established with the task to support and continue the standardization processes of vitamin D metabolites along with other bone-related biomarkers. In this review, we present the position of this IFCC Committee on Bone Metabolism on the latest developments concerning the measurement and standardization of vitamin D metabolites and its binding protein, as well as clinical indications for their measurement and interpretation of the results.
Collapse
Affiliation(s)
- Konstantinos Makris
- Clinical Biochemistry Department, KAT General Hospital, 14561 Athens, Greece; Laboratory for Research of the Musculoskeletal System "Th. Garofalidis", Medical School, University of Athens, Athens, Greece.
| | - Harjit P Bhattoa
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liège, CHU de Liège, Domaine du Sart-Tilman, B-4000 Liège, Belgium
| | - Karen Phinney
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Christopher T Sempos
- Coordinator, Vitamin D Standardization Program (VDSP), Havre de Grace, MD 21078, USA
| | - Candice Z Ulmer
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Samuel D Vasikaran
- PathWest Laboratory Medicine, Fiona Stanley Hospital, Murdoch, WA, Australia
| | - Hubert Vesper
- Clinical Chemistry Branch, Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, Endocrine Laboratory, Amsterdam Gastroenterology Endocrinology & Metabolism, Vrije Universiteit Amsterdam and University of Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| |
Collapse
|
30
|
Brancatella A, Cappellani D, Kaufmann M, Borsari S, Piaggi P, Baldinotti F, Caligo MA, Jones G, Marcocci C, Cetani F. Do the Heterozygous Carriers of a CYP24A1 Mutation Display a Different Biochemical Phenotype Than Wild Types? J Clin Endocrinol Metab 2021; 106:708-717. [PMID: 33249478 DOI: 10.1210/clinem/dgaa876] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Indexed: 01/07/2023]
Abstract
CONTEXT Human cytochrome P450 24 subfamily A member 1 (CYP24A1) loss-of-function mutations result in impaired activity of the 24-hydroxylase involved in vitamin D catabolism, thus inducing a vitamin D-dependent hypercalcemia. Homozygotes often present an overt clinical phenotype named idiopathic infantile hypercalcemia (IIH), whereas it is debated whether heterozygotes display an abnormal phenotype. OBJECTIVE To compare the clinical and biochemical features of heterozygous carriers of CYP24A1 variant and healthy wild-type controls sharing the same genetic and environmental exposure. METHODS A large family harboring the nonsense c.667A>T, p.Arg223* pathogenic variant in the CYP24A1 gene was evaluated. All subjects underwent clinical and biochemical evaluation and complete analysis of vitamin D metabolites using mass spectroscopy including 1,24,25(OH)3D3. Subjects were divided into 2 groups according to their genotype: heterozygotes and wild-type for the CYP24A1 variant. RESULTS The proband, a 40-year-old man, homozygous for p.Arg223* pathogenic variant, had a history of mild hypercalcemia with a seasonal trend, recurrent nephrolithiasis, and no episodes of acute hypercalcemia. He showed the highest serum levels of fibroblast growth factor 23, the highest 25(OH)D3/24,25(OH)2D3 ratio and undetectable levels of 1,24,25(OH)3D3, which represent indicators of a loss-of-function CYP24A1. Compared with the wild-types, heterozygotes had higher serum calcium and 25(OH)D3 concentrations (P = .017 and P = .025, respectively), without any difference in the other biochemical parameters and in the rate of nephrolithiasis. CONCLUSION Heterozygotes exhibit a biochemical phenotype different from that of wild-type subjects. In clinical practice, these individuals might require surveillance because of the potential risk of developing hypercalcemia and related clinical manifestations if exposed to triggering factors.
Collapse
Affiliation(s)
- Alessandro Brancatella
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Daniele Cappellani
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Simona Borsari
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Paolo Piaggi
- Department of Information Engineering, University of Pisa, Pisa, Italy
| | | | | | - Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Claudio Marcocci
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Filomena Cetani
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| |
Collapse
|
31
|
Molin A, Lemoine S, Kaufmann M, Breton P, Nowoczyn M, Ballandonne C, Coudray N, Mittre H, Richard N, Ryckwaert A, Lavillaureix A, Jones G, Bacchetta J, Kottler ML. Overlapping Phenotypes Associated With CYP24A1, SLC34A1, and SLC34A3 Mutations: A Cohort Study of Patients With Hypersensitivity to Vitamin D. Front Endocrinol (Lausanne) 2021; 12:736240. [PMID: 34721296 PMCID: PMC8548709 DOI: 10.3389/fendo.2021.736240] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 09/07/2021] [Indexed: 12/14/2022] Open
Abstract
Mutations in CYP24A1 (vitamin D 24-hydroxylase) and SLC34A1 (renal phosphate transporter NPT2a) cause autosomal recessive Infantile Hypercalcemia type 1 and 2, illustrating links between vitamin D and phosphate metabolism. Patients may present with hypercalciuria and alternate between chronic phases with normal serum calcium but inappropriately high 1,25-(OH)2D and appropriately low PTH, and acute phases with hypercalcemia with suppressed PTH. Mutations in SLC34A3 and SLC9A3R1 have been associated with phosphate wasting without hypercalcemia. The aims of this study were to evaluate the frequency of mutations in these genes in patients with a medical history suggestive of CYP24A1 mutation to search for a specific pattern. Using next generation sequencing, we screened for mutations in 185 patients with PTH levels < 20 pg/mL, hypercalcemia and/or hypercalciuria, and relatives. Twenty-eight (15%) patients harbored biallelic mutations in CYP24A1 (25) and SLC34A3 (3), mostly associated with renal disease (lithiasis, nephrocalcinosis) (86%). Hypophosphatemia was found in 7 patients with biallelic mutations in CYP24A1 and a normal phosphatemia was reported in 2 patients with biallelic mutations in SLC34A3. Rare variations in SLC34A1 and SLC34A3 were mostly of uncertain significance. Fifteen patients (8%) carried only one heterozygous mutation. Heterozygous relatives carrying SLC34A1 or SLC34A3 variation may present with biochemical changes in mineral metabolism. Two patients' genotype may suggest digenism (heterozygous variations in different genes). No variation was found in SLC9A3R1. As no specific pattern can be found, patients with medical history suggestive of CYP24A1 mutation should benefit from SLC34A1 and SLC34A3 analysis.
Collapse
Affiliation(s)
- Arnaud Molin
- Caen University Hospital, Department of Genetics, Molecular Genetics Laboratory and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Caen, France
- Caen Normandy University, Medical School, Caen, France
- BioTARGEN, Caen Normandy University, Caen, France
- OeReCa, Caen Normandy University, Caen, France
- *Correspondence: Arnaud Molin,
| | - Sandrine Lemoine
- Department of Nephrology and Renal Functional Explorations, Edouard Herriot Hospital, Lyon, France
- University of Lyon, University of Lyon 1, Villeurbanne, France
| | - Martin Kaufmann
- Queen’s University, Department of Biomedical and Molecular Sciences, Kingston, ON, Canada
| | - Pierre Breton
- Caen University Hospital, Department of Genetics, Molecular Genetics Laboratory and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Caen, France
| | - Marie Nowoczyn
- Caen Normandy University, Medical School, Caen, France
- Caen University Hospital, Department of Biochemistry, Caen, France
| | | | - Nadia Coudray
- Caen University Hospital, Department of Genetics, Molecular Genetics Laboratory and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Caen, France
| | - Hervé Mittre
- Caen University Hospital, Department of Genetics, Molecular Genetics Laboratory and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Caen, France
- Caen Normandy University, Medical School, Caen, France
- OeReCa, Caen Normandy University, Caen, France
| | - Nicolas Richard
- Caen University Hospital, Department of Genetics, Molecular Genetics Laboratory and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Caen, France
- BioTARGEN, Caen Normandy University, Caen, France
| | - Amélie Ryckwaert
- Department of Pediatrics, Rennes University Hospital, Rennes, France
| | | | - Glenville Jones
- Queen’s University, Department of Biomedical and Molecular Sciences, Kingston, ON, Canada
| | - Justine Bacchetta
- University of Lyon, University of Lyon 1, Villeurbanne, France
- Reference Center for Rare Kidney Diseases (ORKID), Department of Pediatric Nephrology, Rhumatology and Dermatology, Woman Mother Children Hospital, Bron, France
- Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Department of Pediatric Nephrology, Rhumatology and Dermatology, Woman Mother Children Hospital, Bron, France
- INSERM 1033, Bone Diseases Prevention, Lyon, France
| | - Marie-Laure Kottler
- Caen University Hospital, Department of Genetics, Molecular Genetics Laboratory and Reference Center for Rare Diseases of Calcium and Phosphorus Metabolism (OSCAR), Caen, France
- Caen Normandy University, Medical School, Caen, France
- BioTARGEN, Caen Normandy University, Caen, France
| |
Collapse
|
32
|
Frischknecht L, von Rappard J. [A case report of severe vitamin D intoxication]. MMW Fortschr Med 2020; 162:15-18. [PMID: 33289915 DOI: 10.1007/s15006-020-4502-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A 58-year-old woman presented with a symptomatic, hypertensive crisis, acute kidney failure AKIN2 and a severe hypercalcemia. The parathyroid hormone levels were in the lower normal range with highly elevated Vitamin D levels. For more than half a year she was taking 100'000 IU Vitamin D daily. Under volume loading, calcium-low-diet, Denosumab for blocking calcium resorption from bone and Ketoconazol to inhibit activation of Vitamin D a normalization of the calcium levels as well as an improvement of renal function could be observed. Loss-of-function mutations in the genes CYP24A1 and SLC34A1, involved in vitamin D metabolism leading to hypercalcemia could not be found in this patient.
Collapse
|
33
|
David K, Khalil R, Hannon H, Evenepoel P, Decallonne B. Therapy-Resistant Hypercalcemia in a Patient with Inactivating CYP24A1 Mutation and Recurrent Nephrolithiasis: Beware of Concomitant Hyperparathyroidism. Calcif Tissue Int 2020; 107:524-528. [PMID: 32743688 DOI: 10.1007/s00223-020-00738-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/23/2020] [Indexed: 12/30/2022]
Abstract
We describe a case harboring a homozygous CYP24A1 mutation with mild loss of function, first presenting with recurrent nephrolithiasis from the age of 22 onward, initially associated with hypercalcemia and low PTH concentrations. Over the years, hyperparathyroidism developed, resulting in more severe hypercalcemia. Also, kidney function deteriorated, most probably as a consequence of biopsy-proven nephrocalcinosis. Conventional treatment options for CYP24A1 mutation were not effective and/or tolerated (avoidance of sun exposure, diet, pamidronate, itraconazole). A total parathyroidectomy was performed resulting in a normocalcemic hypoparathyroidism without need for treatment with vitamin D analogs, a positive bone mineral balance and an improved kidney function.
Collapse
Affiliation(s)
- K David
- Department of Chronic Diseases and Metabolism, Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Herestraat 49, ON1 box 902, 3000, Leuven, Belgium.
- Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium.
| | - R Khalil
- Department of Chronic Diseases and Metabolism, Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Herestraat 49, ON1 box 902, 3000, Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium
| | - H Hannon
- Department of Nephrology, Maria Middelares Hospital Ghent, Ghent, Belgium
| | - P Evenepoel
- Department of Immunology and Microbiology, Laboratory of Nephrology, KU Leuven, Leuven, Belgium
- Department of Nephrology and Renal Transplantation, University Hospitals Leuven, Leuven, Belgium
| | - B Decallonne
- Department of Chronic Diseases and Metabolism, Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Herestraat 49, ON1 box 902, 3000, Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|
34
|
De Paolis E, Scaglione GL, De Bonis M, Minucci A, Capoluongo E. CYP24A1 and SLC34A1 genetic defects associated with idiopathic infantile hypercalcemia: from genotype to phenotype. Clin Chem Lab Med 2020; 57:1650-1667. [PMID: 31188746 DOI: 10.1515/cclm-2018-1208] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/22/2019] [Indexed: 02/07/2023]
Abstract
Loss of function mutations in the CYP24A1 gene, involved in vitamin D catabolism and in calcium homeostasis, are known to be the genetic drivers of both idiopathic infantile hypercalcemia (IIH) and adult renal stone disease. Recently, also defects in the SLC34A1 gene, encoding for the renal sodium-phosphate transporter NaPi-IIa, were associated with the disease. IIH typically affects infants and pediatric patients with a syndrome characterized by severe hypercalcemia, hypercalciuria, suppressed parathyroid hormone level and nephrolithiasis. In SLC34A1 mutated carriers, hypophosphatemia is also a typical biochemical tract. IIH may also persist undiagnosed into adulthood, causing an increased risk of nephrocalcinosis and renal complication. To note, a clinical heterogeneity characterizes IIH manifestation, principally due to the controversial gene-dose effect and, to the strong influence of environmental factors. The present review is aimed to provide an overview of the current molecular findings on the IIH disorder, giving a comprehensive description of the association between genotype and biochemical and clinical phenotype of the affected patients. We also underline that patients may benefit from genetic testing into a targeted diagnostic and therapeutic workflow.
Collapse
Affiliation(s)
- Elisa De Paolis
- Laboratory of Molecular Diagnostics and Genomics, Teaching and Research Hospital "Fondazione Policlinico Agostino Gemelli" - IRCCS, Catholic University of the Sacred Heart, Rome, Italy
| | - Giovanni Luca Scaglione
- Laboratory of Molecular Oncology, "Fondazione Giovanni Paolo II", Catholic University of Sacred Heart, Campobasso, Italy
| | - Maria De Bonis
- Laboratory of Molecular Diagnostics and Genomics, Teaching and Research Hospital "Fondazione Policlinico Agostino Gemelli" - IRCCS, Catholic University of the Sacred Heart, Rome, Italy
| | - Angelo Minucci
- Laboratory of Molecular Diagnostics and Genomics, Teaching and Research Hospital "Fondazione Policlinico Agostino Gemelli" - IRCCS, Catholic University of the Sacred Heart, Rome, Italy
| | - Ettore Capoluongo
- Laboratory of Molecular Diagnostics and Genomics, Teaching and Research Hospital "Fondazione Policlinico Agostino Gemelli" - IRCCS, Catholic University of the Sacred Heart, Rome, Italy
| |
Collapse
|
35
|
The interest of oral calcium loads test in the diagnosis and management of pediatric nephrolithiasis with hypercalciuria: Experience from a tertiary pediatric centre. J Pediatr Urol 2020; 16:489.e1-489.e9. [PMID: 32593617 DOI: 10.1016/j.jpurol.2020.05.160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 04/30/2020] [Accepted: 05/22/2020] [Indexed: 11/20/2022]
Abstract
INTRODUCTION The use of calcium load has been forgotten in pediatrics until recently whereas it is of utmost importance to have a practical approach to guide management of hypercalciuric nephrolithiasis. OBJECTIVE The purpose of this study was to evaluate the practical interest of oral calcium loads to improve the overall management of nephrolithiasis in children. METHODS We retrospectively studied all pediatric patients having undergone an oral calcium load in our pediatric nephrology unit between September 2015 and April 2017. RESULTS A total of 16 patients were included, at a median age of 12.0 (5.5-17.5) years. The indications of oral calcium load were: presence of an active urolithiasis without any obvious explanation after ruling out the "classical" biological abnormalities, or presence of hypercalciuria with stones composed of weddellite or carbapatite crystals. Among the 16 patients, 6 (38%) patients displayed absorptive hypercalciuria, 2 (12%) renal leak, 3 (19%) "unclassified" inadapted PTH, and 5 (31%) a normal calcium load test. The result of oral calcium load modified the clinical management in 14 (88%) patients, mainly based on the type of hypercalciuria. It allowed us to individualize nutritional advice: in patients with absorptive hypercalciuria, we proposed calcium intake within the lower normal range for age with dairy products not enriched with vitamin D, with the advice to avoid salt and calcium loads during evenings. Conversely, in patients with resorptive hypercalciuria, we proposed normal calcium intake for age. Showing the results of the calcium load is meaningful to patients and parents, and can be considered as an "educational" tool. DISCUSSION To the best of our knowledge, this study is the first to evaluate the interest of calcium load in children with nephrolithiasis in an era of routine PTH and 1-25-D assessment. Here, we demonstrate the feasibility and safety of oral calcium load in children, its interest to understand the underlying mechanisms of hypercalciuria, and its major interest as an "educational tool" for patients to explain them the underlying mechanisms and thus guide the therapeutic management using an individualized dietary approach. This study did not include many patients, but to the best of our knowledge, this is the first study evaluating and validating the feasibility of a safe and non-expensive diagnosis tool in pediatric hypercalciuria. CONCLUSION Oral calcium load is helpful to guide therapeutic adaptation in pediatrics using an individualized dietary approach.
Collapse
|
36
|
Makris K, Sempos C, Cavalier E. The measurement of vitamin D metabolites part II-the measurement of the various vitamin D metabolites. Hormones (Athens) 2020; 19:97-107. [PMID: 32221839 DOI: 10.1007/s42000-020-00188-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/10/2020] [Indexed: 12/18/2022]
Abstract
Today, the possibility exists to measure a number of different vitamin D metabolites with accurate and precise methods. The most abundant vitamin D metabolite, 25(OH)D, is considered the best marker for estimating vitamin D status and is therefore the most commonly measured in clinical practice. There is no consensus on the added value of measuring other metabolites beyond 25-hydroxyvitamin D, although, in some special clinical scenarios and complicated cases, these metabolites may provide just the information needed for an accurate diagnosis. The problem this review addresses is which metabolite to measure and when and how to measure it.
Collapse
Affiliation(s)
- Konstantinos Makris
- Clinical Biochemistry Department, KAT General Hospital, 2 Nikis Str., 14561, Kifissia, Greece.
| | - Christopher Sempos
- Vitamin D Standardization Program (VDSP), Havre de Grace, MD, 21078, USA
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liege, CHU de Liege, Belgium
| |
Collapse
|
37
|
Griffin TP, Joyce CM, Alkanderi S, Blake LM, O’Keeffe DT, Bogdanet D, Islam MN, Dennedy MC, Gillan JE, Morrison JJ, O’Brien T, Sayer JA, Bell M, O’Shea PM. Biallelic CYP24A1 variants presenting during pregnancy: clinical and biochemical phenotypes. Endocr Connect 2020; 9:530-541. [PMID: 32375123 PMCID: PMC7354719 DOI: 10.1530/ec-20-0150] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Inactivating mutations in CYP24A1, encoding vitamin D-24-hydroxylase, can lead to an accumulation of active vitamin D metabolites and consequent hypercalcaemia. Patient (infantile and adult) presentation is varied and includes mild-severe hypercalcaemia, hypercalciuria, nephrocalcinosis and nephrolithiasis. This study aimed to characterize the clinical and biochemical phenotypes of a family with two CYP24A1 missense variants. METHODS The proband and seven family members underwent detailed clinical and biochemical evaluation. Laboratory measurements included serum calcium, intact parathyroid hormone (iPTH), vitamin D metabolites and urine calcium and creatinine. RESULTS The proband presented during the second trimester of a planned pregnancy with flu-like symptoms. Laboratory tests showed elevated adjusted calcium of 3.27 (upper reference limit (URL: 2.30) mmol/L), suppressed iPTH (<6 ng/L), elevated 25(OH)D (264 (URL: 55) nmol/L) and elevated 1,25(OH)D (293 (URL: <280) pmol/L). Ionized calcium was 1.55 (URL: 1.28) mmol/L. Sanger sequencing revealed two heterozygous missense variants in the CYP24A1: p.(Arg439Cys), R439C and p.(Trp275Arg), W275R. The proband's brother and sister had the same genotype. The brother had intermittent hypercalcaemia and hypervitaminosis D. Only the sister had a history of nephrolithiasis. The proband's daughter and two nephews were heterozygous for the R439C variant. The proband and her brother frequently had elevated 25(OH)D:24,25(OH)2D ratios (>50) during follow-up. CONCLUSIONS W275R is a new pathogenic CYP24A1 mutation in compound heterozygotic form with R439C in this family.
Collapse
Affiliation(s)
- Tomás P Griffin
- Centre for Endocrinology, Diabetes and Metabolism, Saolta University Health Care Group (SUHCG), Galway University Hospitals (GUH), Galway, Ireland
- Regenerative Medicine Institute at CÚRAM SFI Research Centre, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - Caroline M Joyce
- Department of Clinical Biochemistry, Cork University Hospital, Cork, Ireland
| | - Sumaya Alkanderi
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Liam M Blake
- Department of Clinical Biochemistry, SUHCG, GUH, Galway, Ireland
| | - Derek T O’Keeffe
- Centre for Endocrinology, Diabetes and Metabolism, Saolta University Health Care Group (SUHCG), Galway University Hospitals (GUH), Galway, Ireland
| | - Delia Bogdanet
- Centre for Endocrinology, Diabetes and Metabolism, Saolta University Health Care Group (SUHCG), Galway University Hospitals (GUH), Galway, Ireland
| | - Md Nahidul Islam
- Regenerative Medicine Institute at CÚRAM SFI Research Centre, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
- Department of Clinical Biochemistry, SUHCG, GUH, Galway, Ireland
| | - Michael C Dennedy
- Centre for Endocrinology, Diabetes and Metabolism, Saolta University Health Care Group (SUHCG), Galway University Hospitals (GUH), Galway, Ireland
- Lambe Institute for Translational Research, School of Medicine, NUIG, Galway, Ireland
| | - John E Gillan
- Department of Histopathology, SUHCG, GUH, Galway, Ireland
| | - John J Morrison
- Department of Obstetrics and Gynaecology, SUHCG, GUH, Galway, Ireland
| | - Timothy O’Brien
- Centre for Endocrinology, Diabetes and Metabolism, Saolta University Health Care Group (SUHCG), Galway University Hospitals (GUH), Galway, Ireland
- Regenerative Medicine Institute at CÚRAM SFI Research Centre, School of Medicine, National University of Ireland Galway (NUIG), Galway, Ireland
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Newcastle upon Tyne NHS Hospitals Foundation Trust, Newcastle upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, UK
| | - Marcia Bell
- Centre for Endocrinology, Diabetes and Metabolism, Saolta University Health Care Group (SUHCG), Galway University Hospitals (GUH), Galway, Ireland
| | - Paula M O’Shea
- Department of Clinical Biochemistry, SUHCG, GUH, Galway, Ireland
- Correspondence should be addressed to P M O’Shea:
| |
Collapse
|
38
|
Abstract
PURPOSE OF REVIEW As the incidence of urinary stone disease in children is increasing, identifying dietary risk factors becomes vitally important, especially in the context of targeting interventions to reduce risk for stone formation. Indiscriminant dietary restrictions are not appropriate for paediatric patients. RECENT FINDINGS Although large, prospective studies are still needed to better quantify dietary risk factors for paediatric stone formers, a number of smaller studies provide data to identify common risk factors to help prevent stone formation, while minimizing inappropriate dietary restrictions. SUMMARY Interpretation of 24-h urine samples to identify individualized dietary risk factors is crucial for implementing a strategy for prevention of further urinary stone formation in children. Clinicians should avoid generalized dietary restrictions in stone-forming children uninformed by laboratory data.
Collapse
|
39
|
Bikle D, Christakos S. New aspects of vitamin D metabolism and action - addressing the skin as source and target. Nat Rev Endocrinol 2020; 16:234-252. [PMID: 32029884 DOI: 10.1038/s41574-019-0312-5] [Citation(s) in RCA: 163] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/12/2019] [Indexed: 12/19/2022]
Abstract
Vitamin D has a key role in stimulating calcium absorption from the gut and promoting skeletal health, as well as many other important physiological functions. Vitamin D is produced in the skin. It is subsequently metabolized to its hormonally active form, 1,25-dihydroxyvitamin D (1,25(OH)2D), by the 1-hydroxylase and catabolized by the 24-hydroxylase. In this Review, we pay special attention to the effect of mutations in these enzymes and their clinical manifestations. We then discuss the role of vitamin D binding protein in transporting vitamin D and its metabolites from their source to their targets, the free hormone hypothesis for cell entry and HSP70 for intracellular transport. This is followed by discussion of the vitamin D receptor (VDR) that mediates the cellular actions of 1,25(OH)2D. Cell-specific recruitment of co-regulatory complexes by liganded VDR leads to changes in gene expression that result in distinct physiological actions by 1,25(OH)2D, which are disrupted by mutations in the VDR. We then discuss the epidermis and hair follicle, to provide a non-skeletal example of a tissue that expresses VDR that not only makes vitamin D but also can metabolize it to its hormonally active form. This enables vitamin D to regulate epidermal differentiation and hair follicle cycling and, in so doing, to promote barrier function, wound healing and hair growth, while limiting cancer development.
Collapse
Affiliation(s)
- Daniel Bikle
- Departments of Medicine and Dermatology, University of California San Francisco, San Francisco, CA, USA.
- VA Medical Center, San Francisco, CA, USA.
| | - Sylvia Christakos
- Departments of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, the State University of New Jersey, Newark, NJ, USA
| |
Collapse
|
40
|
Bikle DD. Vitamin D: Newer Concepts of Its Metabolism and Function at the Basic and Clinical Level. J Endocr Soc 2020; 4:bvz038. [PMID: 32051922 PMCID: PMC7007804 DOI: 10.1210/jendso/bvz038] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/06/2020] [Indexed: 02/08/2023] Open
Abstract
The interest in vitamin D continues unabated with thousands of publications contributing to a vast and growing literature each year. It is widely recognized that the vitamin D receptor (VDR) and the enzymes that metabolize vitamin D are found in many cells, not just those involved with calcium and phosphate homeostasis. In this mini review I have focused primarily on recent studies that provide new insights into vitamin D metabolism, mechanisms of action, and clinical applications. In particular, I examine how mutations in vitamin D metabolizing enzymes-and new information on their regulation-links vitamin D metabolism into areas such as metabolism and diseases outside that of the musculoskeletal system. New information regarding the mechanisms governing the function of the VDR elucidates how this molecule can be so multifunctional in a cell-specific fashion. Clinically, the difficulty in determining vitamin D sufficiency for all groups is addressed, including a discussion of whether the standard measure of vitamin D sufficiency, total 25OHD (25 hydroxyvitamin) levels, may not be the best measure-at least by itself. Finally, several recent large clinical trials exploring the role of vitamin D supplementation in nonskeletal diseases are briefly reviewed, with an eye toward what questions they answered and what new questions they raised.
Collapse
Affiliation(s)
- Daniel D Bikle
- Department of Medicine and Endocrine Research Unit, Veterans Affairs Medical Center and University of California, San Francisco, California
| |
Collapse
|
41
|
Arnold N, O’Toole V, Huynh T, Smith HC, Luxford C, Clifton-Bligh R, Eastman CJ. Intractable hypercalcaemia during pregnancy and the postpartum secondary to pathogenic variants in CYP24A1. Endocrinol Diabetes Metab Case Rep 2019; 2019:EDM190114. [PMID: 31751313 PMCID: PMC6893306 DOI: 10.1530/edm-19-0114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 10/29/2019] [Indexed: 01/09/2023] Open
Abstract
SUMMARY Parathyroid-independent hypercalcaemia of pregnancy, due to biallelic loss of function of the P450 enzyme CYP24A1, the principal inactivator of 1,25(OH)2D results in hypervitaminosis D, hypercalcaemia and hypercalciuria. We report two cases of this disorder, with intractable hypercalcaemia, one occurring during gestation and into the postpartum, and the other in the postpartum period. Case 1, a 47-year-old woman with a twin pregnancy conceived by embryo transfer, presented with hypercalcaemia at 23 weeks gestation with subnormal serum parathyroid hormone (PTH) and normal serum 25-OH D levels. She was admitted to hospital at 31 weeks gestation with pregnancy-induced hypertension, gestational diabetes and increasing hypercalcaemia. Caesarean section at 34 weeks gestation delivered two healthy females weighing 2.13 kg and 2.51 kg. At delivery, the patient's serum calcium level was 2.90 mmol/L. Postpartum severe hypercalcaemia was treated successfully with Denosumab 60 mg SCI, given on two occasions. CYP24A1 testing revealed she was compound heterozygous for pathogenic variants c.427_429delGAA, (p.Glu143del) and c.1186C>T, (p.Arg396Trp). Case 2, a 36-year-old woman presented 4 days after the delivery of healthy twins with dyspnoea, bradycardia, severe headaches, hypertension and generalized tonic-clonic seizures after an uneventful pregnancy. She was hypercalcaemic with a suppressed PTH, normal 25(OH)D, and elevated 1,25(OH)2D levels. Her symptoms partially responded to i.v. saline and corticosteroids in the short term but bisphosphonates such as Pamidronate and Zoledronic acid did not result in sustained improvement. Denosumab 120 mg SCI successfully treated the hypercalcaemia which resolved completely 2 months post-partum. CYP24A1 testing revealed she was homozygous for the pathogenic variant c.427_429delGAA, (p.Glu143del). LEARNING POINTS Hypercalcaemia in pregnancy can be associated with considerable morbidity with few options available for management. In non-PTH-related hypercalcaemia the diagnosis of CYP24A1 deficiency should be considered. Making a definitive diagnosis of CYP24A1 deficiency by genetic testing delays the diagnosis, while the availability of serum 24,25-dihydroxyvitamin D (24,25(OH)2D) will expedite a diagnosis. In pregnant women with CYP24A1 deficiency hypercalcaemia can worsen in the post-partum period and is more likely to occur with twin pregnancies but generally resolves within 2-3 months. Therapeutic alternatives are limited in pregnancy and their effectiveness is short-lived and mostly ineffective. Denosumab used in both our patients after delivery was the most effective agent normalizing calcium and may have benefit as a long-term therapeutic agent in preventing complications in patients with CYP24A1 deficiency.
Collapse
Affiliation(s)
- Nirusha Arnold
- Westmead Private Hospital, Westmead, Sydney, New South Wales, Australia
| | - Victor O’Toole
- Westmead Private Hospital, Westmead, Sydney, New South Wales, Australia
| | - Tien Huynh
- Westmead Private Hospital, Westmead, Sydney, New South Wales, Australia
| | - Howard C Smith
- Westmead Teaching Hospital, Royal North Shore Teaching Hospital, The University of Sydney, Sydney, New South Wales, Australia
| | - Catherine Luxford
- Kolling Institute of Medical Research, Royal North Shore Teaching Hospital, The University of Sydney, Sydney, New South Wales, Australia
| | - Roderick Clifton-Bligh
- Kolling Institute of Medical Research, Royal North Shore Teaching Hospital, The University of Sydney, Sydney, New South Wales, Australia
| | - Creswell J Eastman
- Westmead Private Hospital, Westmead, Sydney, New South Wales, Australia
- Westmead Teaching Hospital, Royal North Shore Teaching Hospital, The University of Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
42
|
Molecular characterization of a recurrent 10.9 kb CYP24A1 deletion in Idiopathic Infantile Hypercalcemia. Eur J Med Genet 2019; 62:103577. [DOI: 10.1016/j.ejmg.2018.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 10/01/2018] [Accepted: 11/09/2018] [Indexed: 12/29/2022]
|
43
|
Bouillon R, Bikle D. Vitamin D Metabolism Revised: Fall of Dogmas. J Bone Miner Res 2019; 34:1985-1992. [PMID: 31589774 PMCID: PMC9000993 DOI: 10.1002/jbmr.3884] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/06/2019] [Accepted: 09/24/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Roger Bouillon
- Laboratory of Clinical and Experimental Endocrinology, Department of Chronic Diseases Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Dan Bikle
- Medicine and Dermatology, University of California San Francisco and VA Medical Center, San Francisco, CA, USA
| |
Collapse
|
44
|
Christakos S, Li S, De La Cruz J, Bikle DD. New developments in our understanding of vitamin metabolism, action and treatment. Metabolism 2019; 98:112-120. [PMID: 31226354 PMCID: PMC6814307 DOI: 10.1016/j.metabol.2019.06.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/07/2019] [Accepted: 06/14/2019] [Indexed: 12/14/2022]
Abstract
Although vitamin D has been reported to have pleiotropic effects including effects on the immune system and on cancer progression, the principal action of vitamin D is the maintenance of calcium and phosphate homeostasis. The importance of vitamin D in this process is emphasized by the consequences of vitamin D deficiency which includes rickets in children and osteomalacia in adults. Vitamin D deficiency has also been reported to increase the risk of falls and osteoporotic fractures. Although vitamin D fortification of foods (including dairy products) has contributed to a marked decrease in rickets in the Western world, vitamin D deficiency in children and adults is still prevalent world-wide. This review summarizes new developments in our understanding of vitamin D endocrine system and addresses clinical syndromes related to abnormalities in vitamin D metabolism and action. In addition, the current understanding of the evaluation of vitamin D deficiency and sufficiency and recommendations for achieving vitamin D sufficiency are discussed.
Collapse
Affiliation(s)
- Sylvia Christakos
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, the State University of New Jersey, New Jersey Medical School, Newark, NJ, USA.
| | - Shanshan Li
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, the State University of New Jersey, New Jersey Medical School, Newark, NJ, USA
| | - Jessica De La Cruz
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, the State University of New Jersey, New Jersey Medical School, Newark, NJ, USA
| | - Daniel D Bikle
- Departments of Medicine and Dermatology, University of California and VA Medical Center, San Francisco, CA, USA
| |
Collapse
|
45
|
Jiráčková J, Hyšpler R, Alkanderi S, Pavlíková L, Palicka V, Sayer JA. Novel CYP24A1 Mutation in a Young Male Patient with Nephrolithiasis: Case Report. Kidney Blood Press Res 2019; 44:870-877. [PMID: 31288237 DOI: 10.1159/000500922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/10/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The CYP24A1 gene encodes the vitamin D 24-hydroxylase enzyme, which hydroxylates active forms of vitamin D into inactive forms. Biallelic mutations in the CYP24A1 gene can lead to elevated levels of active vitamin D metabolites and, consequently, to hypercalcemia, hypercalciuria, nephrocalcinosis, and nephrolithiasis; however, monoallelic mutations have been associated only with milder phenotypes. In the present manuscript, we report the case of a young male patient who presented hypercalcemia and nephrolithiasis, suppressed parathormone, and elevated 1,25 dihydroxy vitamin D levels. METHODS Biochemical analyses were performed on Cobas 8000, F. Hoffmann-La Roche AG, Basel, Switzerland. The proband was initially evaluated for occult malignancies by body imaging, serum electrophoresis, and tumor markers, which did not reveal any pathology. DNA samples of the proband and his sibling were then examined using Sanger sequencing. RESULTS Genetic analysis revealed 2 compound heterozygous CYP24A1 mutations (p.L148P and p.R223*). The novel nonsense CYP24A1 mutation, p.R223*, was also found heterozygously in other family members with a medical history of nephrolithiasis. CONCLUSIONS The identification of this gene mutation causing hypercalcemia, hypercalciuria, and renal stones allows the specific management of endogenous vitamin D production.
Collapse
Affiliation(s)
- Jana Jiráčková
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia, .,Department of Gerontology and Metabolism, University Hospital Hradec Králové, Hradec Králové, Czechia, .,Faculty of Medicine, Charles University, Hradec Králové, Czechia,
| | - Radomir Hyšpler
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia.,Faculty of Medicine, Charles University, Hradec Králové, Czechia
| | - Sumaya Alkanderi
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Ladislava Pavlíková
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia.,Faculty of Medicine, Charles University, Hradec Králové, Czechia
| | - Vladimir Palicka
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia.,Faculty of Medicine, Charles University, Hradec Králové, Czechia
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom.,Newcastle upon Tyne NHS Hospitals Foundation Trust, Newcastle, United Kingdom.,NIHR Newcastle Biomedical Research Centre, Newcastle, United Kingdom
| |
Collapse
|
46
|
Bertholet-Thomas A, Tram N, Dubourg L, Lemoine S, Molin A, Bacchetta J. Fluconazole as a New Therapeutic Tool to Manage Patients With NPTIIc (SLC34A3) Mutation: A Case Report. Am J Kidney Dis 2019; 73:886-889. [DOI: 10.1053/j.ajkd.2018.12.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 12/06/2018] [Indexed: 11/11/2022]
|
47
|
Bettuzzi T, Ram-Wolff C, Hau E, de Masson A, Vignon-Pennamen MD, Beylot-Barry M, Cormier C, Bagot M. Severe hypercalcemia complicating granulomatous slack skin disease: an exceptional case. J Eur Acad Dermatol Venereol 2019; 33:e354-e356. [PMID: 31026372 DOI: 10.1111/jdv.15646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- T Bettuzzi
- Dermatology Department, Hospital St Louis, Paris 7 University, 1 Avenue Claude Vellefaux, 75010, Paris, France
| | - C Ram-Wolff
- Dermatology Department, Hospital St Louis, Paris 7 University, 1 Avenue Claude Vellefaux, 75010, Paris, France
| | - E Hau
- Dermatology Department, Hospital St Louis, Paris 7 University, 1 Avenue Claude Vellefaux, 75010, Paris, France
| | - A de Masson
- Dermatology Department, Hospital St Louis, Paris 7 University, 1 Avenue Claude Vellefaux, 75010, Paris, France
| | - M D Vignon-Pennamen
- Pathology Department, Hospital St Louis, Paris 7 University, 1 Avenue Claude Vellefaux, 75010, Paris, France
| | - M Beylot-Barry
- Dermatology Department, CHU Bordeaux, Bordeaux University, Hospital Saint-André, 1 rue Jean Burguet, 33075, Bordeaux, France
| | - C Cormier
- Rhumatology Department, Hospital Cochin, Paris 5 University, 27 rue du faubourg saint Jacques, 75014, Paris, France
| | - M Bagot
- Dermatology Department, Hospital St Louis, Paris 7 University, 1 Avenue Claude Vellefaux, 75010, Paris, France
| |
Collapse
|
48
|
Hereditary Hypercalcemia Caused by a Homozygous Pathogenic Variant in the CYP24A1 Gene: A Case Report and Review of the Literature. Case Rep Endocrinol 2019; 2019:4982621. [PMID: 31089432 PMCID: PMC6476011 DOI: 10.1155/2019/4982621] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 03/26/2019] [Indexed: 01/22/2023] Open
Abstract
Introduction Loss of function mutations of CYP24A1 gene, which is involved in vitamin D catabolism, cause vitamin D-mediated PTH-independent hypercalcemia. The phenotype varies from life-threatening forms in the infancy to milder forms in the adulthood. Case Presentation We report a case of a 17-year-old woman with a history of nephrolithiasis, mild PTH-independent hypercalcemia (10,5mg/dL), and high serum 1,25(OH)2D concentrations (107pg/mL). Other causes of hypercalcemia associated with the above biochemical signature were excluded. Family history revealed nephrolithiasis in the sister. Blood testing in first-degree relatives showed serum PTH in the low-normal range and 1,25(OH)2D at the upper normal limit or slightly elevated. The CYP24A1 gene analysis revealed a known homozygous loss-of-function pathogenic variant (c.428_430delAAG, rs777676129, p.Glu143del). The panel of vitamin D metabolites evaluated by liquid chromatography showed the typical profile of CYP24A1 mutations, namely, low 24,25(OH)2D3, elevated 25(OH)D3:24,25(OH)2D3 ratio, and undetectable 1,24,25(OH)3D3. The parents and both the siblings harbored the same variant in heterozygosis. We decided for a watchful waiting approach and the patient remained clinically and biochemically stable over a 24-month followup. Conclusion CYP24A1 gene mutations should be considered in cases of PTH-independent hypercalcemia, once that more common causes (hypercalcemia of malignancy, granulomatous diseases, and vitamin D intoxication) have been ruled out.
Collapse
|
49
|
Sun Y, Shen J, Hu X, Qiao Y, Yang J, Shen Y, Li G. CYP24A1 Variants in Two Chinese Patients with Idiopathic Infantile Hypercalcemia. Fetal Pediatr Pathol 2019; 38:44-56. [PMID: 30633617 DOI: 10.1080/15513815.2018.1492052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Biallelic pathogenic variants in CYP24A1 can cause idiopathic infantile hypercalcemia (HCINF). METHODS We report 2 additional molecular abnormalities in 2 Chinese children with CHINF1. RESULTS Biallelic variants in CYP24A1 were found in two patients. Patient One was compound heterozygous for c.449 + 1G > T and c.1426_1427delCT. Patient Two was compound heterozygous for c.1310C > A and c.1426_1427delCT. The c.1310C > A and c.449 + 1G > T were two different novel CYP24A1 variants. Multiple computational tools predicted that both impact protein function. A total of 36 variants have been previously reported in patients with HCINF1, of which 27 were classified as pathogenic or likely pathogenic and nine as uncertain clinical significance. CONCLUSION Genetic tests are helpful in order to counsel the susceptible individuals to avoid vitamin D and take preventive measures in order to avoid complications.
Collapse
Affiliation(s)
- Yan Sun
- a Shandong Provincial Hospital Affiliated to Shandong University , Jinan , China
| | - Jun Shen
- b Department of Pathology, Brigham and Women's Hospital , Harvard Medical School , Boston , MA , USA
| | - Xuyun Hu
- c Shanghai Children's Medical Center , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,d Beijing Key Laboratory for Genetics of Birth Defects, Beijing Pediatric Research Institute; Genetics and Birth Defects Control Center, National Center for Children's Health; MOE Key Laboratory of Major Diseases in Children; Beijing Children's Hospital , Capital Medical University, Beijing , China
| | - Yu Qiao
- a Shandong Provincial Hospital Affiliated to Shandong University , Jinan , China
| | - Jianmei Yang
- a Shandong Provincial Hospital Affiliated to Shandong University , Jinan , China
| | - Yiping Shen
- c Shanghai Children's Medical Center , Shanghai Jiao Tong University School of Medicine , Shanghai , China.,e Division of Genetics and Genomics , Boston Children's Hospital, Harvard Medical School , Boston , MA , USA.,f The Maternity and Child Health Hospital of Guangxi , Nanning , China
| | - Guimei Li
- a Shandong Provincial Hospital Affiliated to Shandong University , Jinan , China
| |
Collapse
|
50
|
Meeting report of the "Symposium on kidney stones and mineral metabolism: calcium kidney stones in 2017". J Nephrol 2019; 32:681-698. [PMID: 30680550 DOI: 10.1007/s40620-019-00587-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023]
Abstract
A symposium on kidney stones and mineral metabolism held on December 2017 in Brussels, Belgium was the first international multidisciplinary conference of the International Collaborative Network on Kidney Stones and Mineral Metabolism. This meeting addressed epidemiology, underlying pathophysiological mechanisms, genetics, pathological, as well as clinical and research topics. The participants included clinicians and recognized experts in the field from Europe and the United States interacted closely during the symposium which promoted a chance to explore new frontiers in the field of kidney stone disease. This manuscript summarizes some of the major highlights of the meeting.
Collapse
|