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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.
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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
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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.
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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
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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.
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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.
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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.
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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.
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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.
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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
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Brancatella A, Cappellani D, Kaufmann M, Semeraro A, Borsari S, Sardella C, Baldinotti F, Caligo MA, Jones G, Marcocci C, Cetani F. Long-term Efficacy and Safety of Rifampin in the Treatment of a Patient Carrying a CYP24A1 Loss-of-Function Variant. J Clin Endocrinol Metab 2022; 107:e3159-e3166. [PMID: 35569070 DOI: 10.1210/clinem/dgac315] [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: 02/01/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND Pharmacological therapy may be useful in the treatment of moderate to severe hypercalcemia in patients with infantile hypercalcemia-1 (HCINF1) due to pathogenic variants in the cytochrome P450 24 subfamily A member 1 (CYP24A1). Rifampin is an antituberculosis drug that is a potent inducer of cytochrome P450 3 subfamily A member 4, which is involved in an alternative catabolic pathway of vitamin D. The efficacy of rifampin in improving hypercalcemia was previously reported, but many questions remain on the long-term efficacy and safety. The aim of the study is to test the long-term efficacy and safety of rifampin in a patient with HCINF1. METHODS We report clinical, biochemical, and imaging features of a 23-year-old man affected by HCINF1 with moderate hypercalcemia (12.9 mg/dL), symptomatic nephrolithiasis, nephrocalcinosis, and impaired kidney function [estimated glomerular filtration rate (eGFR) 60 mL/min/1.73 m2] treated with rifampin for an overall period of 24 months. Kidney, liver, and adrenal function were evaluated at every follow-up visit. RESULTS In 2 months, rifampin induced a normalization of serum calcium (9.6 mg/dL) associated with an improvement of kidney function (eGFR 92 mL/min/1.73 m2) stable during the treatment. After 15 months, rifampin was temporally withdrawn because of asthenia, unrelated to impairment of adrenal function. After 3 months, the timing of drug administration was shifted from the morning to the evening, obtaining the remission of asthenia. At the end of follow-up, the nephrolithiasis disappeared and the nephrocalcinosis was stable. CONCLUSIONS Rifampin could represent an effective choice to induce a stable reduction of calcium levels in patients with HCINF1, with a good safety profile.
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Affiliation(s)
| | - Daniele Cappellani
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Antonella Semeraro
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Simona Borsari
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | | | - Fulvia Baldinotti
- Laboratory of Molecular Genetics, University Hospital 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, University of Pisa, Pisa, Italy
- University Hospital of Pisa, Endocrine Unit, Pisa, Italy
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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.
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Affiliation(s)
- Karl Peter Schlingmann
- Department of General Pediatrics, University Children's Hospital, Albert-Schweitzer-Campus 1, Münster 48149, Germany.
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8
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Duplex high resolution melting analysis (dHRMA) to detect two hot spot CYP24A1 pathogenic variants (PVs) associated to idiopathic infantile hypercalcemia (IIH). Mol Biol Rep 2021; 48:3303-3311. [PMID: 33864587 PMCID: PMC8172411 DOI: 10.1007/s11033-021-06324-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/27/2021] [Indexed: 11/06/2022]
Abstract
Pathogenic variants (PVs) in CYP24A1 gene are associated with Idiopathic Infantile Hypercalcemia disease (IIH). The identification of CYP24A1 PVs can be a useful tool for the improvement of target therapeutic strategies. Aim of this study is to set up a rapid and inexpensive High Resolution Melting Analysis (HRMA)-based method for the simultaneous genotyping of two hot spot PVs in CYP24A1 gene, involved in IIH. A duplex-HRMA (dHRMA) was designed in order to detect simultaneously CYP24A1 c.428_430delAAG, p.(Glu143del) (rs777676129) and c.1186C > T, p.(Arg396Trp) (rs114368325), in peculiar cases addressed to our Laboratory. dHRMA was able to identify clearly and simultaneously both hot spot CYP24A1 PVs evaluating melting curve shape and melting temperature (Tm). This is the first dHRMA approach to rapidly screen the two most frequent CYP24A1 PVs in peculiar case, providing useful information for diagnosis and patient management in IIH disease.
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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: 3] [Impact Index Per Article: 1.0] [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.
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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
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