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Statha E, Paltoglou G, Doulgeraki A, Vakali E, Vlachopapadopoulou E, Economou S, Sakou II, Soldatou A, Karavanaki K, Fryssira E. A toddler with severe vitamin D-dependent rickets type 1 A (VDDR1A), hungry bone syndrome, and severe RSV infection: presentation and therapeutic challenges. Hormones (Athens) 2024:10.1007/s42000-024-00579-2. [PMID: 39034346 DOI: 10.1007/s42000-024-00579-2] [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: 02/12/2024] [Accepted: 06/25/2024] [Indexed: 07/23/2024]
Abstract
BACKGROUND Vitamin D-dependent rickets type 1 A (VDDR1A) is an autosomal recessive disorder due to mutations in the CYP27B1 gene which result in inability to generate 1,25(OH)2D. CASE PRESENTATION An 18-month-old boy with VDDR1A presented with hypotonia and respiratory distress. He had been diagnosed 2 months earlier, having been evaluated for stunted growth, hypotonia, and delayed developmental milestones. He was stabilized with oxygen and bronchodilators for his bronchiolitis and high doses of alfacalcidol, calcium, and phosphate supplements for his hungry bone syndrome. Of note, the patient sustained upper limb fractures after a fall from his bed during admission. Overall, he had a protracted disease course; however, his bone profile gradually improved and he steadily recovered. CONCLUSION VDDR1A causes failure to thrive, hypotonia, and increased fracture risk and may complicate the clinical course of lower respiratory tract infections. Furthermore, management of hungry bone syndrome requires supraphysiologic doses of vitamin D metabolites and calcium.
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Affiliation(s)
- Eleni Statha
- 2nd Department of Pediatrics, National and Kapodistrian University of Athens (NKUA), "P. & A. Kyriakou" Children's Hospital, Athens, Greece
| | - George Paltoglou
- 2nd Department of Pediatrics, National and Kapodistrian University of Athens (NKUA), "P. & A. Kyriakou" Children's Hospital, Athens, Greece
| | - Artemis Doulgeraki
- Department of Bone and Mineral Metabolism, Institute of Child Health, Athens, Greece
| | - Eleni Vakali
- Department of Endocrinology-Growth and Development, P. & A. Kyriakou Children's Hospital, Athens, Greece
| | - Elpis Vlachopapadopoulou
- Department of Endocrinology-Growth and Development, P. & A. Kyriakou Children's Hospital, Athens, Greece.
| | - Stavroula Economou
- 2nd Department of Pediatrics, National and Kapodistrian University of Athens (NKUA), "P. & A. Kyriakou" Children's Hospital, Athens, Greece
| | - Irini-Ikbale Sakou
- 2nd Department of Pediatrics, National and Kapodistrian University of Athens (NKUA), "P. & A. Kyriakou" Children's Hospital, Athens, Greece
| | - Alexandra Soldatou
- 2nd Department of Pediatrics, National and Kapodistrian University of Athens (NKUA), "P. & A. Kyriakou" Children's Hospital, Athens, Greece
| | - Kyriaki Karavanaki
- 2nd Department of Pediatrics, National and Kapodistrian University of Athens (NKUA), "P. & A. Kyriakou" Children's Hospital, Athens, Greece
| | - Elena Fryssira
- Medical Genetics Laboratory, National and Kapodistrian University of Athens (NKUA), Aghia Sophia Children's Hospital, Athens, Greece
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2
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Wang LKP, Shanmugasundaram M, Cooney E, Lee PDK. Siblings with vitamin D-dependent rickets type 1A: Importance of genetic testing and a review of genotype-phenotype correlations. Am J Med Genet A 2024:e63780. [PMID: 38822637 DOI: 10.1002/ajmg.a.63780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/09/2024] [Accepted: 05/18/2024] [Indexed: 06/03/2024]
Abstract
Vitamin D-dependent rickets type 1A (VDDR1A) is a rare condition caused by biallelic pathogenic variants in CYP27B1, which encodes 25-hydroxyvitamin D3-1-α-hydroxylase. Inadequate activity of this enzyme results in deficient 1α-hydroxylation of inactive 25-hydroxyvitamin D to biologically active 1,25-dihydroxyvitamin D, with consequent adverse effects on calcium and phosphate metabolism. A female child was clinically diagnosed at 18 months old with hypophosphatemic rickets based on phenotype and biochemical testing, with neither parent affected. A subsequent affected male sibling led to the reconsideration of the diagnosis. Exome sequencing showed a homozygous CYP27B1 c.1040T>A (p.Ile347Asn) variant for both children. No variants were found in genes associated with hypophosphatemic rickets. A review of published cases of VDDR1A with homozygous CYP27B1 variants indicates variable clinical presentation, lack of genotype-phenotype correlation, and low serum phosphate at diagnosis in most cases. These findings emphasize the clinical importance of molecular testing as part of the diagnostic evaluation for cases of non-nutritional rickets.
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Affiliation(s)
| | | | - Erin Cooney
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
| | - Phillip D K Lee
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, USA
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3
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AlSubaihin A, Harrington J. Hereditary Rickets: A Quick Guide for the Pediatrician. Curr Pediatr Rev 2024; 20:380-394. [PMID: 36475338 DOI: 10.2174/1573396319666221205123402] [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: 04/12/2022] [Revised: 09/10/2022] [Accepted: 11/01/2022] [Indexed: 12/12/2022]
Abstract
With the increased discovery of genes implicated in vitamin D metabolism and the regulation of calcium and phosphate homeostasis, a growing number of genetic forms of rickets are now recognized. These are categorized into calciopenic and phosphopenic rickets. Calciopenic forms of hereditary rickets are caused by genetic mutations that alter the enzymatic activity in the vitamin D activation pathway or impair the vitamin D receptor action. Hereditary forms of phosphopenic rickets, on the other hand, are caused by genetic mutations that lead to increased expression of FGF23 hormone or that impair the absorptive capacity of phosphate at the proximal renal tubule. Due to the clinical overlap between acquired and genetic forms of rickets, identifying children with hereditary rickets can be challenging. A clear understanding of the molecular basis of hereditary forms of rickets and their associated biochemical patterns allow the health care provider to assign the correct diagnosis, avoid non-effective interventions and shorten the duration of the diagnostic journey in these children. In this mini-review, known forms of hereditary rickets listed on the Online Mendelian Inheritance in Man database are discussed. Further, a clinical approach to identify and diagnose children with hereditary forms of rickets is suggested.
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Affiliation(s)
- Abdulmajeed AlSubaihin
- Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- King Saud University Medical City, Riyadh, Saudi Arabia
| | - Jennifer Harrington
- Division of Endocrinology, Women's and Children's Health Network, North Adelaide, Australia
- Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
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Milan KL, Jayasuriya R, Harithpriya K, Anuradha M, Ramkumar KM. Impact of vitamin D resistance genes on vitamin D deficiency during pregnancy among the South Indian population. J Reprod Immunol 2023; 160:104143. [PMID: 37738710 DOI: 10.1016/j.jri.2023.104143] [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: 03/12/2023] [Revised: 08/21/2023] [Accepted: 09/03/2023] [Indexed: 09/24/2023]
Abstract
Increasing evidence suggests that vitamin D (Vit-D) could be pivotal in maintaining normal glucose homeostasis. Low levels of Vit-D in early pregnancy are associated with a higher risk of gestational diabetes mellitus (GDM). Though several reports have highlighted the prevalence of vit-D deficiency among pregnant women, its underlying cause has not yet been fully elucidated. In this connection, a few studies have found the development of resistance to Vit-D, including the levels of Vitamin D receptor (VDR) and transcription regulators that modify VDR action, as well as the bioavailability of Vit-D. We aimed to determine the levels of Vit-D resistance genes such as 25-HydroxyVit-D-24-hydroxylase (CYP24A1), VDR repressor genes (SNAIL and SMRT) and their association between Vit-D concentrations in early pregnancy, and the risk of gestational diabetes mellitus (GDM). A prospective observational study was conducted on healthy pregnant women (NGDM; n = 50) and GDM (n = 50) attending routine antenatal care at SRM Medical College Hospital, Chennai, recruited at 12 weeks of gestation. We found that the serum levels of Vit-D were low in GDM subjects and negatively correlated with the fasting glucose levels. Further, increased expressions of Vit-D resistance genes such as CYP24A1, SNAIL, and SMRT were observed in GDM subjects and negatively correlated with the serum levels of Vit-D. Furthermore, we have validated the data using the trophoblast cell line, BeWo, exposed to calcitriol under a hyperglycemic environment. Our finding showed that increased expression of Vit-D resistance genes in pregnancy may be associated with a greater risk of adverse pregnancy outcomes, including GDM.
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Affiliation(s)
- K L Milan
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - R Jayasuriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - K Harithpriya
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - M Anuradha
- Department of Obstetrics & Gynaecology, SRM Medical College Hospital and Research Centre, Kattankulathur 603203, Tamil Nadu, India
| | - K M Ramkumar
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India.
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5
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Voltan G, Cannito M, Ferrarese M, Ceccato F, Camozzi V. Vitamin D: An Overview of Gene Regulation, Ranging from Metabolism to Genomic Effects. Genes (Basel) 2023; 14:1691. [PMID: 37761831 PMCID: PMC10531002 DOI: 10.3390/genes14091691] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/17/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
Vitamin D is a pro-hormone characterized by an intricate metabolism and regulation. It is well known for its role in calcium and phosphate metabolism, and in bone health. However, several studies have assessed a huge number of extra-skeletal functions, ranging from cell proliferation in some oncogenic pathways to antioxidant and immunomodulatory functions. Vitamin D exerts its role by binding to VDRs (vitamin D receptors), which are located in many different tissues. Moreover, VDRs are able to bind hundreds of genomic loci, modulating the expression of various primary target genes. Interestingly, plenty of gene polymorphisms regarding VDRs are described, each one carrying a potential influence against gene expression, with relapses in several chronic diseases and metabolic complications. In this review, we provide an overview of the genetic aspects of vitamin D and VDR, emphasizing the gene regulation of vitamin D, and the genetic modulation of VDR target genes. In addition, we briefly summarize the rare genetic disease linked to vitamin D metabolism.
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Affiliation(s)
- Giacomo Voltan
- Department of Medicine (DIMED), University of Padova, Via Giustiniani 2, 35128 Padova, Italy; (G.V.); (M.C.); (M.F.); (V.C.)
- Endocrinology Unit, Padova University Hospital, Via Ospedale Civile 105, 35128 Padova, Italy
| | - Michele Cannito
- Department of Medicine (DIMED), University of Padova, Via Giustiniani 2, 35128 Padova, Italy; (G.V.); (M.C.); (M.F.); (V.C.)
- Endocrinology Unit, Padova University Hospital, Via Ospedale Civile 105, 35128 Padova, Italy
| | - Michela Ferrarese
- Department of Medicine (DIMED), University of Padova, Via Giustiniani 2, 35128 Padova, Italy; (G.V.); (M.C.); (M.F.); (V.C.)
- Endocrinology Unit, Padova University Hospital, Via Ospedale Civile 105, 35128 Padova, Italy
| | - Filippo Ceccato
- Department of Medicine (DIMED), University of Padova, Via Giustiniani 2, 35128 Padova, Italy; (G.V.); (M.C.); (M.F.); (V.C.)
- Endocrinology Unit, Padova University Hospital, Via Ospedale Civile 105, 35128 Padova, Italy
| | - Valentina Camozzi
- Department of Medicine (DIMED), University of Padova, Via Giustiniani 2, 35128 Padova, Italy; (G.V.); (M.C.); (M.F.); (V.C.)
- Endocrinology Unit, Padova University Hospital, Via Ospedale Civile 105, 35128 Padova, Italy
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6
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Zamanfar D, Ghazaiean M. An overview of CYP27B1 enzyme mutation and management: A case report and review of the literature. Clin Case Rep 2023; 11:e7007. [PMID: 36879673 PMCID: PMC9984874 DOI: 10.1002/ccr3.7007] [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: 10/06/2022] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Vitamin D-dependent rickets type 1 (VDDRIA) is an autosomal recessive disorder caused by mutations in the Cytochrome P450 Family 27 Subfamily B Member 1 (CYP27B1) gene, which encodes for the enzyme 1 alpha-hydroxylase. We report a known case of VDDRIA with hypotonia, growth and developmental disorders and discuss about the mutation and its management.
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Affiliation(s)
- Daniel Zamanfar
- Pediatric Endocrinologist, Diabetes Research Center of MazandaranMazandaran University of Medical SciencesSariIran
| | - Mobin Ghazaiean
- Student Research CommitteeMazandaran University of Medical SciencesSariIran
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7
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Aftab S, Khan SA, Malik MI, Imran A, Anjum MN, Saeed A, Qureshi AA, Cheema HA. Clinical spectrum and diagnostic challenges of vitamin D dependent rickets type 1A (VDDR1A) caused by CYP27B1 mutation in resource limited countries. J Pediatr Endocrinol Metab 2023; 36:152-157. [PMID: 36524979 DOI: 10.1515/jpem-2022-0550] [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: 10/27/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
OBJECTIVES Vitamin D dependent rickets type 1A (VDDR1A) is a rare autosomal recessive condition due to inactivating mutation of CYP27B1. It mimics clinically, biochemically and rediologically to nutritional and hypophosphatemic rickets. In developing countries like Pakistan, VDDR1A is often misdiagnosed as nutritional rickets or hypophosphatemic rickets due lack of free access to 1,25 (OH) 2 D level and genetic testing. This study was aimed to determine the clinical spectrum and diagnostic challenges of VDDR1A due to CYP27B1 mutation in developing countries. METHODS Retrospective review of all cases of VDDR1A due to CYP27B1 mutation over a period of two years presenting in the Pediatric Endocrine clinic of Hameed Latif Hospital, Lahore, Pakistan. RESULTS Six cases of VDDR1A (4 males) were identified. Mean age of clinical manifestation was 14 (9-24) months. Mean age of presentation to endocrine department was 5.5 (1.5-11.8) years. Growth failure and bony deformities were the most common presentation (n=6), followed by repeated diarrheas and abdominal distension (n=3) and recurrent fractures (n=1). All cases shared same biochemical profile of low/normal calcium, hypophosphatemia, raised alkaline phosphatase, raised PTH, normal/high 25(OH)D and tubular reabsorption of phosphate (TRP) <85%. Patients treated with calcitriol showed rapid healing as compared to those treated with 1-alfacalcidol. CONCLUSIONS We should have a high index of suspicion of VDDR1A in rickets not responding to cholecalciferol therapy.
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Affiliation(s)
- Sommayya Aftab
- Department of Paediatric Endocrinology and Diabetes, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan.,Paediatric Endocrinology, Hameed Lateef Hospital, Lahore, Pakistan
| | - Sabeen Abid Khan
- Department of Paediatrics, Shifa College of Medicine, Shifa Tameer-r-Millat University, Islamabad
| | - Munir Iqbal Malik
- Department of Paediatrics, Shifa College of Medicine, Shifa Tameer-e-Millat University, Islamabad, Pakistan.,Consultant Paediatric Gastroenterologist, Shifa International Hospital, Islamabad, Pakistan
| | - Ahmed Imran
- Department of Paediatric Radiology, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan
| | - Muhammad Nadeem Anjum
- Department of Paediatric Gastroenterology , Hepatology and Nutrition, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan
| | - Anjum Saeed
- Department of Paediatric Gastroenterology , Hepatology and Nutrition, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan
| | - Abid Ali Qureshi
- Department of Paediatric Radiology, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan
| | - Huma Arshad Cheema
- Department of Paediatric Gastroenterology , Hepatology and Nutrition, University of Child Health Sciences, The Children's Hospital, Lahore, Pakistan
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Yıldırım R, Ünal E, Tekmenüray A. Evaluation of Clinical Characteristics of Vitamin D Dependent Rickets Type 1 (VDDR-1) Patients and Importance of Early Diagnosis. GÜNCEL PEDIATRI 2022. [DOI: 10.4274/jcp.2022.66564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Yi C, Xu J, He J, Zhang X, Zhang X, Huang J. Lifelong deformities in an adult caused by vitamin D‑dependent rickets type 1A: A case report. Exp Ther Med 2022; 24:762. [PMID: 36561972 PMCID: PMC9748631 DOI: 10.3892/etm.2022.11698] [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: 05/04/2022] [Accepted: 09/30/2022] [Indexed: 11/13/2022] Open
Abstract
Vitamin D-dependent rickets (VDDR) type 1A is a rare autosomal recessive disorder caused by cytochrome P450 family 27 subfamily B member 1 (CYP27B1) mutations and can lead to deficiencies in 1α-hydroxylase activity. The present study describes the case of a 39-year-old male patient who presented with rickets and deformities of limbs. Blood biochemical analysis revealed hypocalcemia and high serum parathyroid hormone (PTH) levels. Whole-exome Sanger sequencing using peripheral venous blood of this patient and his parents revealed exon1 c.182T>C, a novel mutation. Through physical examination, laboratory tests, imaging including lower limbs and lumbar spine X-ray and pelvis CT scan, and genetic testing, the patient was diagnosed with VDDR-1A. Following 1 month of treatment with 0.5 µg 1,25-dihydroxy-vitamin D3 twice daily and 0.6 g calcium carbonate once daily, follow-up examinations revealed that the patient's PTH and serum calcium levels had returned to normal. As the patient was diagnosed in his adulthood and missed the optimal treatment period, he developed irreversible deformities. If VDDR-1A can be diagnosed during infancy and childhood, skeletal deformities may be prevented. Therefore, the present report supports the proposal of early genetic sequencing in children with calcium deficiencies for the early diagnosis of rare diseases such as VDDR-1A, -1B and -2A and hereditary hypophosphatemic rickets. Since VDDR-1A diagnosed in adults is rare, the present case may provide clinicians with further insights into the characteristics of this rare disease.
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Affiliation(s)
- Caihong Yi
- Department of Rheumatology and Immunology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Juan Xu
- Department of Endocrinology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Jiangping He
- Department of Rheumatology and Immunology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Xiaofang Zhang
- Department of Rheumatology and Immunology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Xianfeng Zhang
- Department of Endocrinology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China,Correspondence to: Dr Jiao Huang, Department of Rheumatology and Immunology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, 261 Huansha Road, Hangzhou, Zhejiang 310006, P.R. China
| | - Jiao Huang
- Department of Rheumatology and Immunology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China,Correspondence to: Dr Jiao Huang, Department of Rheumatology and Immunology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, 261 Huansha Road, Hangzhou, Zhejiang 310006, P.R. China
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Wang SF, Zhou T, Du MR, Sheng J. Identification of vitamin D-dependent rickets type IA caused by a mutation of the CYP27B1 by whole exome sequencing. Asian J Surg 2022; 45:1160-1161. [DOI: 10.1016/j.asjsur.2022.01.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/07/2022] [Indexed: 11/28/2022] Open
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11
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Albader N, Zou M, BinEssa HA, Abdi S, Al-Enezi AF, Meyer BF, Alzahrani AS, Shi Y. Insights of Noncanonical Splice-site Variants on RNA Splicing in Patients With Congenital Hypothyroidism. J Clin Endocrinol Metab 2022; 107:e1263-e1276. [PMID: 34632506 DOI: 10.1210/clinem/dgab737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Congenital hypothyroidism (CH) is caused by mutations in the genes for thyroid hormone synthesis. In our previous investigation of CH patients, approximately 53% of patients had mutations in either coding exons or canonical splice sites of causative genes. Noncanonical splice-site variants in the intron were detected but their pathogenic significance was not known. OBJECTIVE This work aims to evaluate noncanonical splice-site variants on pre-messenger RNA (pre-mRNA) splicing of CH-causing genes. METHODS Next-generation sequencing data of 55 CH cases in 47 families were analyzed to identify rare intron variants. The effects of variants on pre-mRNA splicing were investigated by minigene RNA-splicing assay. RESULTS Four intron variants were found in 3 patients: solute carrier family 26 member 4 (SLC26A4) c.1544+9C>T and c.1707+94C>T in one patient, and solute carrier family 5 member 5 (SLC5A5) c.970-48G>C and c.1652-97A>C in 2 other patients. The c.1707+94C>T and c.970-48G>C caused exons 15 and 16 skipping, and exon 8 skipping, respectively. The remaining variants had no effect on RNA splicing. Furthermore, we analyzed 28 previously reported noncanonical splice-site variants (4 in TG and 24 in SLC26A4). Among them, 15 variants (~ 54%) resulted in aberrant splicing and 13 variants had no effect on RNA splicing. These data were compared with 3 variant-prediction programs (FATHMM-XF, FATHMM-MKL, and CADD). Among 32 variants, FATHMM-XF, FATHMM-MKL, and CADD correctly predicted 20 (63%), 17 (53%), and 26 (81%) variants, respectively. CONCLUSION Two novel deep intron mutations have been identified in SLC26A4 and SLC5A5, bringing the total number of solved families with disease-causing mutations to approximately 45% in our cohort. Approximately 46% (13/28) of reported noncanonical splice-site mutations do not disrupt pre-mRNA splicing. CADD provides highest prediction accuracy of noncanonical splice-site variants.
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Affiliation(s)
- Najla Albader
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11495, Saudi Arabia
| | - Minjing Zou
- Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Huda A BinEssa
- Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Saba Abdi
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11495, Saudi Arabia
| | - Anwar F Al-Enezi
- Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Brian F Meyer
- Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Ali S Alzahrani
- Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Yufei Shi
- Centre for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
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Al Homyani DK, Alhemaiani SK. Novel Homozygous CYP27B1 Gene Mutation in Vitamin D-Dependent Rickets Type 1A (VDDR1A) Disorder: A Case Report. Front Endocrinol (Lausanne) 2022; 13:862022. [PMID: 35663328 PMCID: PMC9157501 DOI: 10.3389/fendo.2022.862022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 03/14/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Vitamin D-dependent rickets type 1A (VDDR1A) rickets is an uncommon kind of rickets that affects both boys and girls. Children with mutations are normal at birth and present at around 6 months to 2 years of age with symptoms. When suspected, genetic testing is required to confirm the diagnosis. CASE PRESENTATION This is a case report of VDDR1A in a 4-year-old boy who presented with delayed growth, inability to stand, and rachitic bone deformities. The diagnosis was reached by anthropometric measurement, bone profile, and radiological studies, then confirmed by genetic testing, which revealed a homozygous pathogenic variant in the CYP27B1 gene. He was treated with Vitamin-D (alfacalcidol) and oral calcium. CONCLUSION VDDR1A is caused by a mutation in the CYP27B1 gene, which impairs the 1 hydroxylase enzyme, which compromises vitamin-D production.
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Affiliation(s)
- Doua Khalid Al Homyani
- Endocrine Division, Department of Pediatrics, Taif Children Hospital, Taif, Saudi Arabia
- *Correspondence: Doua Khalid Al Homyani, ; Shahad Khalid Alhemaiani,
| | - Shahad Khalid Alhemaiani
- Radiology Division, King Abdulaziz Specialist Hospital, Taif, Saudi Arabia
- *Correspondence: Doua Khalid Al Homyani, ; Shahad Khalid Alhemaiani,
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Fortin CA, Girard L, Bonenfant C, Leblanc J, Cruz-Marino T, Blackburn ME, Desmeules M, Bouchard L. Benefits of Newborn Screening for Vitamin D-Dependant Rickets Type 1A in a Founder Population. Front Endocrinol (Lausanne) 2022; 13:887371. [PMID: 35600579 PMCID: PMC9120640 DOI: 10.3389/fendo.2022.887371] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Vitamin D-dependant rickets type 1A (VDDR1A) is a rare autosomal recessive disorder caused by pathogenic variants in the CYP27B1 gene. This gene is essential for vitamin D activation. Although VDDR1A is a rare condition worldwide, its prevalence is high in the Saguenay-Lac-Saint-Jean (SLSJ) region due to a founder effect. Daily intake of calcitriol before the onset of clinical manifestations can prevent them in affected children. METHODS A genetic screening test was developed and validated for the CYP27B1 gene c.262del pathogenic variant. Newborn screening was implemented in the SLSJ region for this variant, and the feasibility and acceptability were assessed. Sixteen medical records of children affected with VDDR1A were reviewed to document the consequences of the disease at diagnosis. RESULTS A total of 2000 newborns were tested for VDDR1A. Most families (96.5%) accepted the genetic test. We found a carrier rate of 1/29 for the c.262delG variant in our cohort, which is suggestive of a founder effect. We identified one child affected with VDDR1A and treatment was initiated before the onset of clinical manifestations. On average, children with VDDR1A were diagnosed at 13.8 ± 5 months of age, they had a significant failure to thrive at diagnosis, among other harmful health consequences. CONCLUSION Our study showed that in our population, the newborn genetic screening program is safe and feasible, it has high acceptability, and it is efficient to identify affected children. VDDR1A health consequences can be prevented by early initiation of treatment. Therefore, screening programs should be available for populations where it is deemed as beneficial from a public health perspective.
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Affiliation(s)
- Carol-Ann Fortin
- Biochemistry and Functional Genomics Department, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Lysanne Girard
- Biochemistry and Functional Genomics Department, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Chloé Bonenfant
- Biochemistry and Functional Genomics Department, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Josianne Leblanc
- Department of Laboratory Medicine, Centre intégré universitaire de santé et de services sociaux (CIUSSS) du Saguenay-Lac-Saint-Jean – Hôpital de Chicoutimi, Chicoutimi, QC, Canada
| | - Tania Cruz-Marino
- Department of Laboratory Medicine, Centre intégré universitaire de santé et de services sociaux (CIUSSS) du Saguenay-Lac-Saint-Jean – Hôpital de Chicoutimi, Chicoutimi, QC, Canada
| | | | - Mathieu Desmeules
- Medicine Department, FHMS, Université de Sherbrooke, Sherbrooke, QC, Canada
- Clinique des maladies métaboliques, CIUSSS du Saguenay-Lac-Saint-Jean – Hôpital de Chicoutimi, Chicoutimi, QC, Canada
- *Correspondence: Luigi Bouchard, ; Mathieu Desmeules,
| | - Luigi Bouchard
- Biochemistry and Functional Genomics Department, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Sherbrooke, QC, Canada
- Department of Laboratory Medicine, Centre intégré universitaire de santé et de services sociaux (CIUSSS) du Saguenay-Lac-Saint-Jean – Hôpital de Chicoutimi, Chicoutimi, QC, Canada
- *Correspondence: Luigi Bouchard, ; Mathieu Desmeules,
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Lin Y, Guan Z, Mei H, Zhang W, Zhou Z, Su L, Cheng J, Zheng R, Liang C, Cai Y, Yin X, Wu D, Liu L, Zeng C. Clinical characteristics and long-term outcomes of 12 children with vitamin D-dependent rickets type 1A: A retrospective study. Front Pediatr 2022; 10:1007219. [PMID: 36405822 PMCID: PMC9671943 DOI: 10.3389/fped.2022.1007219] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Vitamin D-dependent rickets type 1A (VDDR1A) is a rare autosomal recessive disorder caused by deficiency of the CYP27B1 gene. This study aims to investigate the phenotypic and genotypic features of VDDR1A children in southern China and evaluate the long-term therapeutic effects. METHODS Twelve children from southern China with VDDR1A were enrolled in this study. Their clinical, radiological, biochemical, and molecular findings were analyzed retrospectively. The rickets severity score (RSS), biochemical parameters, and height standard deviation score (HtSDS) were used to evaluate clinical outcomes. RESULTS Six males and six females were included in this VDDR1A cohort. The age of onset was from 6 months to 1.8 years, and the age at diagnosis was 2.1 ± 0.8 years. The most common clinical symptoms at diagnosis were delayed walking (10/12) and severe growth retardation (9/12). HtSDS at diagnosis was negatively associated with age (p < 0.05). All patients presented with hypocalcemia, hypophosphatemia, increased serum alkaline phosphatase and parathyroid hormone, and high RSS at diagnosis. Two allelic variants of the CYP27B1 gene were identified in all patients, including nine different variants, four known and five novel, with c.1319_1325dupCCCACCC(p.Phe443Profs*24) being the most frequent. All patients were treated with calcitriol and calcium after diagnosis, and all patients but one were followed-up from 6 months to 15.6 years. HtSDS, RSS, and biochemical parameters were found to be improved during the first few years of the treatment. However, only five patients had good compliance. Although RSS and biochemical parameters were significantly improved, the HtSDS change was not significant from the time of diagnosis to the last visit, and seven patients remained of a short stature (HtSDS < -2). CONCLUSION Our study extends the mutational spectrum of VDDR1A and finds a hotspot variant of the CYP27B1 gene in southern China. The results reconfirm the importance of early diagnosis and treatment compliance and reveal the challenge of height improvement in VDDR1A patients.
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Affiliation(s)
- Yunting Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Zhihong Guan
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Huifen Mei
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Wen Zhang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Zhizi Zhou
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Ling Su
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Jing Cheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Ruidan Zheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Cuili Liang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Yanna Cai
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Xi Yin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Dongyan Wu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
| | - Chunhua Zeng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China
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15
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Ozden A, Doneray H. The genetics and clinical manifestations of patients with vitamin D dependent rickets type 1A. J Pediatr Endocrinol Metab 2021; 34:781-789. [PMID: 33823104 DOI: 10.1515/jpem-2020-0691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/12/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Vitamin D dependent rickets type 1A (VDDR-1A) is a very rare autosomal recessive disorder caused by mutations in the CYP27B1, which encodes vitamin D 1α-hydroxylase. We report the genetics and clinical manifestations of nine patients with VDDR-1A and compare our patients to other cases with the same mutations in the literature. METHODS The clinical presentations, clinical and laboratory findings and treatment modalities of the patients were evaluated retrospectively. RESULTS The mean age of the patients at the time of diagnosis was 39.9 months (range: 4.5-111). At the time of diagnosis, six patients had received stoss vitamin D therapy. Clinical findings related to rickets were obvious in seven patients and unclear in two patients. Except for one case, all patients had laboratory findings of rickets. A novel variant and four previously reported mutations in CYP27B1 were identified. The mean calcitriol and elemental calcium dose were 45.5 ng/kg/day (range: 20-70) and 75.6 mg/kg/day (range: 45-125), respectively. CONCLUSIONS We found a novel compound heterozygous mutation consisting of a reported duplication [(p.F443Pfs*24 (c.1319_1325 dup CCCACCC)] in exon 8 and a novel deletion [p.D507Efs*34 (c.1521 delC)] in exon 9. Our study suggests that the clinical manifestations and laboratory findings of the patients with VDDR1A are variable even among the patients with the same mutation.
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Affiliation(s)
- Ayse Ozden
- Department of Pediatric Endocrinology, Erzurum Regional Training & Research Hospital, Erzurum, Turkey
| | - Hakan Doneray
- Department of Pediatric Endocrinology, Ataturk University Faculty of Medicine, Erzurum, Turkey
- Clinical Research Development and Design Application and Research Center, Ataturk University, Erzurum, Turkey
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Kaygusuz SB, Alavanda C, Kirkgoz T, Eltan M, Yavas Abali Z, Helvacioglu D, Guran T, Ata P, Bereket A, Turan S. Does Genotype-Phenotype Correlation Exist in Vitamin D-Dependent Rickets Type IA: Report of 13 New Cases and Review of the Literature. Calcif Tissue Int 2021; 108:576-586. [PMID: 33386952 DOI: 10.1007/s00223-020-00784-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/28/2020] [Indexed: 11/28/2022]
Abstract
Vitamin D-dependent rickets type IA (VDDR-IA) is caused by biallelic mutations in CYP27B1. Data regarding genotype-phenotype correlation in VDDR-IA are scarce. Here, we aimed to investigate clinical/genotypic features and long-term follow-up of 13 new cases with VDDR-IA and genotype-phenotype correlation of reported cases in the literature. Thirteen patients with VDDR-IA were evaluated. Eight patients had reached their final height at the time of the study and, for whom, long-term outcome data were analyzed. Further, all VDDR-IA patients in the literature (n:183) were analyzed and clinical-genetic features were recorded. The median age of diagnosis was 2.55 ± 1.13 (1.0-12) years. Initial diagnoses before referral to our clinic were nutritional rickets (n:7), hypophosphatemic rickets (n:2), and pseudohypoparathyroidism (n:1). All had biochemical evidence suggestive of VDDR-IA; except one with elevated 1,25(OH)2D3 and another with hyperphosphatemia, in whom pseudohypoparathyroidism was excluded with molecular tests. Combined analyses of our cohort and other series in the literature demonstrated that three most common CYP27B1 mutations are p.F443Pfs*24, c.195 + 2T > G, and p.V88Wfs*71. In Turkish population, p.K192E mutation along with the former two is the most common mutations. Comparison of clinical features demonstrated that c.195 + 2T > G mutation causes the most severe and p.K192E mutation causes the least severe phenotype with respect to age and height at presentation and calcitriol requirement. We found a clear genotype-phenotype correlation in VDDR-IA, notably CYP27B1 intronic c.195 + 2T > G mutation causes a more severe phenotype with lower height SDS at presentation and, higher calcitriol requirement, while less severe phenotype occurs in p.K192E mutation.
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Affiliation(s)
- Sare Betul Kaygusuz
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Ceren Alavanda
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Tarik Kirkgoz
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Mehmet Eltan
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Zehra Yavas Abali
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Didem Helvacioglu
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Tulay Guran
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Pinar Ata
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Abdullah Bereket
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Serap Turan
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey.
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Zhong J, Xie Y, Dang Y, Zhang J, Song Y, Lan D. Use of RNA‑sequencing to detect abnormal transcription of the collagen α‑2 (VI) chain gene that can lead to Bethlem myopathy. Int J Mol Med 2021; 47:28. [PMID: 33537799 PMCID: PMC7895517 DOI: 10.3892/ijmm.2021.4861] [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: 03/15/2020] [Accepted: 11/27/2020] [Indexed: 11/13/2022] Open
Abstract
Bethlem myopathy (BM) is an autosomal dominant or autosomal recessive disorder and is usually associated with mutations in the collagen VI genes. In the present study, the pathogenicity of a novel splice-site mutation was explored using RNA-sequencing in a family with suspected BM, and a myopathy panel was performed in the proband. The genetic status of all family members was confirmed using Sanger sequencing. Clinical data and magnetic resonance imaging (MRI) features were also documented. In silico analysis was performed to predict the effects of the splice mutation. RNA-sequencing and reverse transcription (RT)-PCR were used to assess aberrant splicing. Immunocytochemistry was conducted to measure collagen VI protein levels within the gastrocnemius and in cultured skin fibroblasts. The results revealed that three patients in the family shared a similar classic BM presentation. MRI revealed distinct patterns of fatty infiltration in the lower extremities. A novel splicing mutation c.736-1G>C in the collagen α-2 (VI) chain (COL6A2) gene was found in all three patients. In silico analysis predicted that the mutation would destroy the normal splice acceptor site. RNA-sequencing detected two abnormal splicing variants adjacent to the mutation site, and RT-PCR confirmed the RNA-sequencing findings. Furthermore, a defect in the collagen protein within cultured fibroblasts was detected using immunocytochemistry. The mutation c.736-1G>C in the COL6A2 gene caused aberrant splicing and led to premature termination of protein translation. In conclusion, these findings may improve our knowledge of mutations of the COL6A2 gene associated with BM and demonstrated that RNA-sequencing can be a powerful tool for finding the underlying mechanism of a disease-causing mutations at a splice site.
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Affiliation(s)
- Jingzi Zhong
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yanshu Xie
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yiwu Dang
- Department of Pathology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Jiapeng Zhang
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yingru Song
- Department of Radiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Dan Lan
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
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18
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Zou M, Guven A, BinEssa HA, Al-Rijjal RA, Meyer BF, Alzahrani AS, Shi Y. Molecular Analysis of CYP27B1 Mutations in Vitamin D-Dependent Rickets Type 1A: c.590G > A (p.G197D) Missense Mutation Causes a RNA Splicing Error. Front Genet 2020; 11:607517. [PMID: 33329754 PMCID: PMC7729158 DOI: 10.3389/fgene.2020.607517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/10/2020] [Indexed: 11/22/2022] Open
Abstract
Context Vitamin D-dependent rickets type 1A (VDDR1A) is a rare autosomal recessively inherited disorder due to loss-of-function mutations in the CYP27B1 gene. CYP27B1 encodes an enzyme of 25-hydroxyvitamin D-1α-hydroxylase for converting inactive 25-OHD to biologically active 1,25-(OH)2D. Objective To identify underlying genetic defects in patients with VDDR1A. Methods Twelve patients from 7 Turkish and 2 Saudi families were investigated. The coding exons and intron-exon boundaries of the CYP27B1 gene were amplified by Polymerase Chain Reaction (PCR) from peripheral lymphocyte DNA. PCR products were directly sequenced. The consequences of c.590G > A mutation were analyzed by in silico and functional analysis. Results CYP27B1 mutations were identified in all the patients. Two novel mutations were identified in two separate families: c.171delG (family 7) and c.398_400dupAAT (family 8). The intra-exon deletion of c.171delG resulted in a frameshift and premature stop codon 20 amino acids downstream from the mutation (p.L58Cfs∗20). The intra-exon duplication of c.398_400dupAAT generated a premature stop codon at the mutation site (p.W134∗). A missense c.590G > A (p.G197D) mutation was found in a patient from family 4 and caused a defect in pre-mRNA splicing. As a result, two populations of transcripts were detected: the majority of them with intron 3 retention (83%), and the minority (17%) being properly spliced transcripts with about 16% of wild-type enzymatic activity. The remaining nine patients from six families carried a previously reported c.1319_1325dupCCCACCC (F443Pfs∗24) mutation. Clinically, all the patients need continued calcitriol treatment, which was consistent with inactivation of 25-hydroxy vitamin D1α-hydroxylase activity. Conclusion Two novel frameshift CYP27B1 mutations were identified and predicted to inactivate 25-hydroxyvitamin D-1α-hydroxylase. The loss of enzymatic activity by c.590G > A missense mutation was mainly caused by aberrant pre-mRNA splicing.
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Affiliation(s)
- Minjing Zou
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Ayla Guven
- Pediatric Endocrinology Clinic, Zeynep Kamil Women and Children Hospital, University of Health Science, Istanbul, Turkey
| | - Huda A BinEssa
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Roua A Al-Rijjal
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Brian F Meyer
- Pediatric Endocrinology Clinic, Zeynep Kamil Women and Children Hospital, University of Health Science, Istanbul, Turkey
| | - Ali S Alzahrani
- Department of Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Yufei Shi
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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Dhull RS, Jain R, Deepthi B, Cheong HI, Saha A, Mehndiratta M, Basu S. Vitamin D-dependent rickets (VDDR) type 1: case series of two siblings with a CYP27B1 mutation and review of the literature. ACTA ACUST UNITED AC 2020; 42:494-497. [PMID: 32926064 PMCID: PMC7860650 DOI: 10.1590/2175-8239-jbn-2020-0001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 06/24/2020] [Indexed: 12/02/2022]
Abstract
Two siblings presented with clinical and biochemical features of rickets, initially suspected as hypophosphatemic rickets. There was no improvement initially, hence the siblings were reinvestigated and later diagnosed as having vitamin D-dependent rickets (VDDR) type 1 due to a rare mutation in the CYP27B1 gene encoding the 1α-hydroxylase enzyme. Both siblings improved with calcitriol supplementation. The initial presentation of VDDR is often confusing and algorithmic evaluation helps in diagnosis. We also present a brief review of the literature, including genetics.
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Affiliation(s)
- Rachita Singh Dhull
- Lady Hardinge Medical College and associated Kalawati Saran Children Hospital, Department of Pediatrics, Division of Pediatric Nephrology, New Delhi, India
| | - Reena Jain
- Lady Hardinge Medical College and associated Kalawati Saran Children Hospital, Department of Pediatrics, Division of Pediatric Nephrology, New Delhi, India
| | - Bobbity Deepthi
- Lady Hardinge Medical College and associated Kalawati Saran Children Hospital, Department of Pediatrics, Division of Pediatric Nephrology, New Delhi, India
| | - Hae Ii Cheong
- Seoul National University Children's Hospital, Department of Pediatrics, Seoul, Korea.,Seoul National University College of Medicine, Kidney Research Institute, Medical Research Centre, Seoul, Korea
| | - Abhijeet Saha
- Lady Hardinge Medical College and associated Kalawati Saran Children Hospital, Department of Pediatrics, Division of Pediatric Nephrology, New Delhi, India
| | - Mohit Mehndiratta
- University College of Medical Sciences, Department of Biochemistry, New Delhi, India
| | - Srikanta Basu
- Lady Hardinge Medical College and associated Kalawati Saran Children Hospital, Department of Pediatrics, Division of Pediatric Nephrology, New Delhi, India
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Cebeci AN, Zou M, BinEssa HA, Alzahrani AS, Al-Rijjal RA, Al-Enezi AF, Al-Mohanna FA, Cavalier E, Meyer BF, Shi Y. Mutation of SGK3, a Novel Regulator of Renal Phosphate Transport, Causes Autosomal Dominant Hypophosphatemic Rickets. J Clin Endocrinol Metab 2020; 105:5672651. [PMID: 31821448 DOI: 10.1210/clinem/dgz260] [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: 07/02/2019] [Accepted: 12/09/2019] [Indexed: 11/19/2022]
Abstract
CONTEXT Hypophosphatemic rickets (HR) is a group of rare hereditary renal phosphate wasting disorders caused by mutations in PHEX, FGF23, DMP1, ENPP1, CLCN5, SLC9A3R1, SLC34A1, or SLC34A3. OBJECTIVE A large kindred with 5 HR patients was recruited with dominant inheritance. The study was undertaken to investigate underlying genetic defects in HR patients. DESIGN Patients and their family members were initially analyzed for PHEX and FGF23 mutations using polymerase chain reaction sequencing and copy number analysis. Exome sequencing was subsequently performed to identify novel candidate genes. RESULTS PHEX and FGF23 mutations were not detected in the patients. No copy number variation was observed in the genome using CytoScan HD array analysis. Mutations in DMP1, ENPP1, CLCN5, SLC9A3R1, SLC34A1, or SLC34A3 were also not found by exome sequencing. A novel c.979-96 T>A mutation in the SGK3 gene was found to be strictly segregated in a heterozygous pattern in patients and was not present in normal family members. The mutation is located 1 bp downstream of a highly conserved adenosine branch point, resulted in exon 13 skipping and in-frame deletion of 29 amino acids, which is part of the protein kinase domain and contains a Thr-320 phosphorylation site that is required for its activation. Protein tertiary structure modelling showed significant structural change in the protein kinase domain following the deletion. CONCLUSIONS The c.979-96 T>A splice mutation in the SGK3 gene causes exon 13 skipping and deletion of 29 amino acids in the protein kinase domain. The SGK3 mutation may cause autosomal dominant HR.
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Affiliation(s)
- Ayşe Nurcan Cebeci
- Department of Pediatric Endocrinology, Istanbul Bilim University, Istanbul, Turkey
| | - Minjing Zou
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Huda A BinEssa
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Ali S Alzahrani
- Department of Medicine King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Roua A Al-Rijjal
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Anwar F Al-Enezi
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Futwan A Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liège, CHU de Liège, Liège, Belgium
| | - Brian F Meyer
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Yufei Shi
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
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21
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Single Nucleotide Polymorphisms in 25-Hydroxyvitamin D3 1-Alpha-Hydroxylase ( CYP27B1) Gene: The Risk of Malignant Tumors and Other Chronic Diseases. Nutrients 2020; 12:nu12030801. [PMID: 32197412 PMCID: PMC7146376 DOI: 10.3390/nu12030801] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/31/2022] Open
Abstract
: Vitamin D is widely known for its roles in the promotion of apoptosis and differentiation, with simultaneous inhibition of proliferation, inflammation, angiogenesis, invasion, and metastasis. Modern literature lacks complete information on polymorphisms in CYP27B1, the only enzyme capable of vitamin D activation. This review presents gathered data that relate to genetic variants in CYP27B1 gene in correlation to multiple diseases, mostly concerning colorectal, prostate, breast, lung, and pancreatic cancers, as well as on other pathologies, such as non-Hodgkin's lymphoma, oral lichen planus, or multiple sclerosis.
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Sepulveda-Villegas M, Elizondo-Montemayor L, Trevino V. Identification and analysis of 35 genes associated with vitamin D deficiency: A systematic review to identify genetic variants. J Steroid Biochem Mol Biol 2020; 196:105516. [PMID: 31678109 DOI: 10.1016/j.jsbmb.2019.105516] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/03/2019] [Accepted: 10/24/2019] [Indexed: 12/19/2022]
Abstract
Vitamin D deficiency is a public health concern associated with, but not limited to, skeletal anomalies, chronic diseases, immune conditions, and cancer, among others. Hypovitaminosis D is mainly associated with environmental and lifestyle factors that affect sunlight exposure. However, genetic factors also influence 25-hydroxyvitamin D (25[OH]D) serum concentration. Although there is available information of genes with clear biological relevance or markers identified by Genome-Wide Association Studies, an overall view and screening tool to identify known genetic causes of altered serum levels of 25(OH)D is lacking. Moreover, there are no studies including the total genetic evidence associated with abnormal serum concentration of 25(OH)D. Therefore, we conducted a de-novo systematic literature review to propose a set of genes comprehensive of all genetic variants reported to be associated with deficiency of vitamin D. Abstracts retrieved from PubMed search were organized by gene and curated one-by-one using the PubTerm web tool. The genes identified were classified according to the type of genetic evidence associated with serum 25(OH)D levels and were also compared with the few commonly screened genes related to vitamin D status. This strategy allowed the identification of 35 genes associated with serum 25(OH)D concentrations, 27 (75%) of which are not commercially available and are not, therefore, analyzed in clinical practice for genetic counseling, nor are they sufficiently studied for research purposes. Functional analysis of the genes identified confirmed their role in vitamin D pathways and diseases. Thus, the list of genes is an important source to understand the genetic determinants of 25(OH)D levels. To further support our findings, we provide a map of the reported functional variants and SNPs not included in ClinVar, minor allelic frequencies, SNP effect sizes, associated diseases, and an integrated overview of the biological role of the genes. In conclusion, we identified a comprehensive candidate list of genes associated with serum 25(OH)D concentrations, most of which are not commercially available, but would prove of importance in clinical practice in screening for patients that should respond to supplementation because of alterations in absorption, patients that would have little benefit because alterations in the downstream metabolism of vitamin D, and to study non-responsiveness to supplementation with vitamin D.
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Affiliation(s)
- Maricruz Sepulveda-Villegas
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Bioinformatics Research Group, Ave. Morones Prieto 3000, Colonia Los Doctores, Monterrey, Nuevo León 64710, Mexico
| | - Leticia Elizondo-Montemayor
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Bioinformatics Research Group, Ave. Morones Prieto 3000, Colonia Los Doctores, Monterrey, Nuevo León 64710, Mexico; Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Center for Research in Clinical Nutrition and Obesity, Ave. Morones Prieto 3000, Colonia Los Doctores, Monterrey, Nuevo León 64710, Mexico; Tecnologico de Monterrey, Cardiovascular and Metabolomics Research Group, Hospital Zambrano Hellion, San Pedro Garza Garcia, P.C., 66278, Mexico
| | - Victor Trevino
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Bioinformatics Research Group, Ave. Morones Prieto 3000, Colonia Los Doctores, Monterrey, Nuevo León 64710, Mexico.
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BinEssa HA, Zou M, Al-Enezi AF, Alomrani B, Al-Faham MSA, Al-Rijjal RA, Meyer BF, Shi Y. Functional analysis of 22 splice-site mutations in the PHEX, the causative gene in X-linked dominant hypophosphatemic rickets. Bone 2019; 125:186-193. [PMID: 31102713 DOI: 10.1016/j.bone.2019.05.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/24/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Abstract
CONTEXT X-linked hypophosphatemic rickets (XLH) is caused by inactivating mutations in the PHEX gene and is the most common form of hereditary rickets. The splice-site mutations account for 17% of all reported PHEX mutations. The functional consequence of these splice-site mutations has not been systemically investigated. OBJECTIVE The current study was undertaken to functionally annotate previously reported 22 splice-site mutations in the PHEX gene. METHODS PHEX mini-genes with different splice-site mutations were created by site-directed mutagenesis and expressed in HEK293 cells. The mRNA transcripts were analyzed by RT-PCR, cloning, and sequencing. RESULTS These splicing mutations led to a variety of consequences, including exon skipping, intron retention, and activation of cryptic splice sites. Among 22 splice-site mutations, exon skipping was the most common event accounting for 73% (16/22). Non-canonical splice-site mutations could result in splicing errors to the same extent as canonical splice-site mutations such as c.436+3G>C, c.436+4A>C, c.436+6T>C, c.437-3C>G, c.850-3C>G, c.1080-3C>A, c.1482+5G>C, c.1586+6T>C, c.1645+5G>A, c.1645+6T>C, c.1701-16T>A, c.1768+5G>A, and c.1899+5G>A. Interestingly, non-canonical (c.436+6T>C and c.1586+6T>C) and canonical splice-site mutations (c.1769-1G>C) could generate partial splicing errors (both wild-type and mutant transcripts were detected), resulting in incomplete inactivation of PHEX gene, which may explain the mild disease phenotype reported previously, providing evidence of genotype-phenotype correlation. c.1645C>T (p.R549*) had no impact on pre-mRNA splicing although it is located next to canonical splice donor site GT. CONCLUSIONS Exon skipping is the most common outcome due to splice-site mutations. Both canonical and non-canonical splice-site mutations can result in either severe or mild RNA splicing defects, contributing to phenotype heterogeneity. Non-canonical splice-site mutations should not be overlooked in genetic screening especially those located within 50 bp from canonical splice site.
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Affiliation(s)
- Huda A BinEssa
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Minjing Zou
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Anwar F Al-Enezi
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Basma Alomrani
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Manar S A Al-Faham
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Roua A Al-Rijjal
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Brian F Meyer
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia
| | - Yufei Shi
- Department of Genetics, King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia.
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Sen A, Stark H. Role of cytochrome P450 polymorphisms and functions in development of ulcerative colitis. World J Gastroenterol 2019; 25:2846-2862. [PMID: 31249444 PMCID: PMC6589734 DOI: 10.3748/wjg.v25.i23.2846] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/26/2019] [Accepted: 05/08/2019] [Indexed: 02/06/2023] Open
Abstract
Cytochromes P450s (CYPs) are terminal enzymes in CYP dependent monooxygenases, which constitute a superfamily of enzymes catalysing the metabolism of both endogenous and exogenous substances. One of their main tasks is to facilitate the excretion of these substances and eliminate their toxicities in most phase 1 reactions. Endogenous substrates of CYPs include steroids, bile acids, eicosanoids, cholesterol, vitamin D and neurotransmitters. About 80% of currently used drugs and environmental chemicals comprise exogenous substrates for CYPs. Genetic polymorphisms of CYPs may affect the enzyme functions and have been reported to be associated with various diseases and adverse drug reactions among different populations. In this review, we discuss the role of some critical CYP isoforms (CYP1A1, CYP2D6, CYP2J2, CYP2R1, CYP3A5, CYP3A7, CYP4F3, CYP24A1, CYP26B1 and CYP27B1) in the pathogenesis or aetiology of ulcerative colitis concerning gene polymorphisms. In addition, their significance in metabolism concerning ulcerative colitis in patients is also discussed showing a clear underestimation in genetic studies performed so far.
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Affiliation(s)
- Alaattin Sen
- Department of Molecular Biology and Genetics, Faculty of Life and Natural Sciences, Abdullah Gul University, Kayseri 38080, Turkey
- Biology Department, Faculty of Arts and Sciences, Pamukkale University, Denizli 20070, Turkey
| | - Holger Stark
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Duesseldorf 40225, Germany
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25
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Dursun F, Özgürhan G, Kırmızıbekmez H, Keskin E, Hacıhamdioğlu B. Genetic and Clinical Characteristics of Patients with Vitamin D Dependent Rickets Type 1A. J Clin Res Pediatr Endocrinol 2019; 11:34-40. [PMID: 30282619 PMCID: PMC6398191 DOI: 10.4274/jcrpe.galenos.2018.2018.0121] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE Vitamin D dependent rickets type 1A (VDDR1A) is an autosomal recessive disorder caused by mutations in the 1α-hydroxylase gene (CYB27B1). As it may be confused with nutritional rickets and hypophosphatemic rickets, genetic analysis is important for making a correct diagnosis. METHODS We analysed genomic DNA from 11 patients from eight different Turkish families. The patients were recruited for our studies if they presented with a diagnosis of VDDR. RESULTS The mean ± standard deviation age at diagnosis was 13.1±7.4 months. Seven patients had mild hypocalcemia at presentation while four patients had normal calcium concentrations. All patients underwent CYP27B1 gene analysis. The most prevalent mutation was the c.195 + 2T>G splice donor site mutation, affecting five out of 11 patients with VDDR1A. Two patients from the fourth family were compound heterozygous for c.195 + 2T>G and c.195 + 2 T>A in intron-1. Two patients, from different families, were homozygous for a previously reported duplication mutation in exon 8 (1319_1325dupCCCACCC, Phe443Profs*24). One patient had a homozygous splice site mutation in intron 7 (c.1215 + 2 T>A) and one patient had a homozygous mutation in exon 9 (c.1474 C>T). CONCLUSION Intron-1 mutation was the most common mutation, as previously reported. All patients carrying that mutation were from same city of origin suggesting a “founder” or a “common ancestor” effect. VDDR1A should definitely be considered when a patient with signs of rickets has a normal 25-OHD level or when there is unresponsiveness to vitamin D treatment.
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Affiliation(s)
- Fatma Dursun
- Ümraniye Training and Research Hospital, Clinic of Pediatric Endocrinology, İstanbul, Turkey,* Address for Correspondence: Ümraniye Training and Research Hospital, Clinic of Pediatric Endocrinology, İstanbul, Turkey Phone: +90 505 267 14 03 E-mail:
| | - Gamze Özgürhan
- Süleymaniye Maternity and Children’s Training and Research Hospital, Clinic of Paediatrics, İstanbul, Turkey
| | - Heves Kırmızıbekmez
- Ümraniye Training and Research Hospital, Clinic of Pediatric Endocrinology, İstanbul, Turkey
| | - Ece Keskin
- Süleymaniye Maternity and Children’s Training and Research Hospital, Clinic of Medical Genetic, İstanbul, Turkey
| | - Bülent Hacıhamdioğlu
- İstinye University Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
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Abstract
Rickets is a metabolic bone disease that develops as a result of inadequate mineralization of growing bone due to disruption of calcium, phosphorus and/or vitamin D metabolism. Nutritional rickets remains a significant child health problem in developing countries. In addition, several rare genetic causes of rickets have also been described, which can be divided into two groups. The first group consists of genetic disorders of vitamin D biosynthesis and action, such as vitamin D-dependent rickets type 1A (VDDR1A), vitamin D-dependent rickets type 1B (VDDR1B), vitamin D-dependent rickets type 2A (VDDR2A), and vitamin D-dependent rickets type 2B (VDDR2B). The second group involves genetic disorders of excessive renal phosphate loss (hereditary hypophosphatemic rickets) due to impairment in renal tubular phosphate reabsorption as a result of FGF23-related or FGF23-independent causes. In this review, we focus on clinical, laboratory and genetic characteristics of various types of hereditary rickets as well as differential diagnosis and treatment approaches.
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Affiliation(s)
- Sezer Acar
- Dokuz Eylül University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey
| | - Korcan Demir
- Dokuz Eylül University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey
| | - Yufei Shi
- King Faisal Specialist Hospital & Research Centre, Department of Genetics, Riyadh, Saudi Arabia
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Miller WL. Genetic disorders of Vitamin D biosynthesis and degradation. J Steroid Biochem Mol Biol 2017; 165:101-108. [PMID: 27060335 DOI: 10.1016/j.jsbmb.2016.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 04/03/2016] [Accepted: 04/05/2016] [Indexed: 01/10/2023]
Abstract
Vitamin D, an inactive secosteroid pro-hormone, is produced by the action of ultraviolet light on 7-dehydrocholesterol in the skin. The active hormone, 1,25(OH)2D is produced by sequential 25-hydroxylation in the liver, principally by CYP2R1, and 1α-hydroxylation in the kidney by CYP27B1. Mutations in CYP27B1 cause 1α-hydroxylase deficiency, also known as vitamin D dependent rickets type I or hereditary pseudo-vitamin D deficient rickets; very rare mutations in CYP2R1 can cause 25-hydroxylase deficiency. Both deficiencies cause hypocalcemia, secondary hyperparathyroidism, severe rickets in infancy, and low serum concentrations of 1,25(OH)2D; both disorders respond to hormonal replacement therapy with calcitriol. The inactivation of vitamin D is principally initiated by its 23- and 24-hydroxylation by CYP24A1. Mutations in CYP24A1 can cause both severe neonatal hypercalcemia and a less severe adult hypercalcemic syndrome. Other pathways of vitamin D metabolism are under investigation, notably its 20-hydroxylation by the cholesterol side-chain cleavage enzyme, CYP11A1.
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Affiliation(s)
- Walter L Miller
- Center for Reproductive Sciences and Department of Pediatrics, HSE 1634, University of California San Francisco, San Francisco, CA 94143-0556, USA.
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Özcabı B, Tahmiscioğlu Bucak F, Jaferova S, Oruç Ç, Adrovic A, Ceylaner S, Ercan O, Evliyaoğlu O. A Case of Vitamin D-Dependent Rickets Type 1A with a Novel Mutation in the Uzbek Population. J Clin Res Pediatr Endocrinol 2016; 8:484-489. [PMID: 27353739 PMCID: PMC5198011 DOI: 10.4274/jcrpe.3128] [Citation(s) in RCA: 4] [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] [Indexed: 12/01/2022] Open
Abstract
Vitamin D-dependent rickets type 1A (VDDR-1A) (Online Mendelian Inheritance in Man #264700) is a rare, autosomal recessively inherited disorder due to inactivating mutations in CYP27B1. It is characterized by early onset of rickets with hypocalcemia. We aimed to describe the clinical and laboratory findings in a VDDR-1A case and to report a novel homozygote truncating mutation NM_000785.3 c.403C>T (p.Q135*) in CYP27B1 which to our knowledge is the first described mutation in the Uzbek population. The patient was admitted with tetany at the age of 12 months. He was a healthy Uzbek boy until 9 months of age when he had a seizure due to hypocalcemia. Vitamin D treatment was given orally in Turkmenistan (no data available for dose and duration). The patient was the product of a consanguineous marriage. His brother had died with hypocalcemia and pneumonia. At physical examination, anthropometric measurements were within normal limits; he had caput quadratum, enlarged wrists, and carpopedal spasm. Blood calcium, phosphorus, alkaline phosphatase, and parathormone (PTH) levels were 5.9 mg/dL, 3.5 mg/dL, 987 IU/L, and 182.8 pg/mL (12-72), respectively. Radiological findings included cupping and fraying of the radial and ulnar metaphyses. Renal ultrasound revealed nephrocalcinosis (grade 1). Despite high serum PTH and 25-hydroxyvitamin D3 levels, 1,25-dihydroxyvitamin D3 level was low, suggesting a diagnosis of VDDR-1A. The patient was treated with calcium carbonate and calcitriol. DNA sequencing revealed a novel homozygous mutation of NM_000785.3 c.403C>T (p.Q135*) in CYP27B1. VDDR-1A is a rare disorder which needs to be considered even in countries where nutritional vitamin D deficiency is still common.
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Affiliation(s)
- Bahar Özcabı
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Feride Tahmiscioğlu Bucak
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Sevinç Jaferova
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Çiğdem Oruç
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Amra Adrovic
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Serdar Ceylaner
- Intergen Genetic Center and Yüksek İhtisas University Faculty of Medicine, Department of Medical Genetics, Ankara, Turkey
| | - Oya Ercan
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey
| | - Olcay Evliyaoğlu
- İstanbul University Cerrahpaşa Faculty of Medicine, Department of Pediatric Endocrinology, İstanbul, Turkey, E-mail:
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Zalewski A, Ma NS, Legeza B, Renthal N, Flück CE, Pandey AV. Vitamin D-Dependent Rickets Type 1 Caused by Mutations in CYP27B1 Affecting Protein Interactions With Adrenodoxin. J Clin Endocrinol Metab 2016; 101:3409-18. [PMID: 27399352 DOI: 10.1210/jc.2016-2124] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
CONTEXT CYP27B1 converts 25-hydroxyvitamin D3 to active 1,25-dihydroxyvitamin D3, playing a vital role in calcium homeostasis and bone growth. Vitamin D-dependent rickets type 1 (VDDR-1) is a rare autosomal recessive disorder caused by mutations in CYP27B1. OBJECTIVE The objective of the study was an enzymatic and structural analysis of mutations in a patient with calcipenic rickets. Design, Setting, Patient, and Intervention: Two siblings presented with calcipenic rickets and normal 1,25-dihydroxyvitamin D3 levels. CYP27B1 gene analysis showed compound heterozygous mutations confirming VDDR-1. We studied wild-type CYP27B1 and mutations H441Y and R459L by computational homology modeling, molecular dynamics simulations, and functional studies using a luciferase assay. The patients were successfully treated with calcitriol. MAIN OUTCOME The main outcomes of the study were novel mutations leading to a severe loss of CYP27B1 activities for metabolism of 25-hydroxyvitamin D3. RESULTS Mitochondrial cytochrome P450s require adrenodoxin (FDX1) and adrenodoxin reductase. We created models of CYP27B1-FDX1 complex, which revealed negative effects of mutations H441Y and R459L. Upon structural analysis, near-identical folds, protein contact areas, and orientations of heme/iron-sulfur cluster suggested that both mutations may destabilize the CYP27B1-FDX1 complex by negating directional interactions with adrenodoxin. This system is highly sensitive to small local changes modulating the binding/dissociation of adrenodoxin, and electron-transporting efficiency might change with mutations at the surface. Functional assays confirmed this hypothesis and showed severe loss of activity of CYP27B1 by both mutations. CONCLUSIONS This is the first report of mutations in CYP27B1 causing VDDR-1 by affecting protein-protein interactions with FDX1 that results in reduced CYP27B1 activities. Detailed characterization of mutations in CYP27B1 is required for understanding the novel molecular mechanisms causing VDDR-1.
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Affiliation(s)
- Adam Zalewski
- Division of Pediatric Endocrinology, Diabetology, and Metabolism (A.Z., B.L., C.E.F., A.V.P.), Department of Pediatrics, University Children's Hospital, Inselspital, Bern, and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland; and Division of Endocrinology (N.S.M., N.R.), Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02114
| | - Nina S Ma
- Division of Pediatric Endocrinology, Diabetology, and Metabolism (A.Z., B.L., C.E.F., A.V.P.), Department of Pediatrics, University Children's Hospital, Inselspital, Bern, and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland; and Division of Endocrinology (N.S.M., N.R.), Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02114
| | - Balazs Legeza
- Division of Pediatric Endocrinology, Diabetology, and Metabolism (A.Z., B.L., C.E.F., A.V.P.), Department of Pediatrics, University Children's Hospital, Inselspital, Bern, and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland; and Division of Endocrinology (N.S.M., N.R.), Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02114
| | - Nora Renthal
- Division of Pediatric Endocrinology, Diabetology, and Metabolism (A.Z., B.L., C.E.F., A.V.P.), Department of Pediatrics, University Children's Hospital, Inselspital, Bern, and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland; and Division of Endocrinology (N.S.M., N.R.), Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02114
| | - Christa E Flück
- Division of Pediatric Endocrinology, Diabetology, and Metabolism (A.Z., B.L., C.E.F., A.V.P.), Department of Pediatrics, University Children's Hospital, Inselspital, Bern, and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland; and Division of Endocrinology (N.S.M., N.R.), Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02114
| | - Amit V Pandey
- Division of Pediatric Endocrinology, Diabetology, and Metabolism (A.Z., B.L., C.E.F., A.V.P.), Department of Pediatrics, University Children's Hospital, Inselspital, Bern, and Department of Clinical Research, University of Bern, CH-3010 Bern, Switzerland; and Division of Endocrinology (N.S.M., N.R.), Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02114
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Koek WNH, Zillikens MC, van der Eerden BCJ, van Leeuwen JPTM. Novel Compound Heterozygous Mutations in the CYP27B1 Gene Lead to Pseudovitamin D-Deficient Rickets. Calcif Tissue Int 2016; 99:326-31. [PMID: 27364341 DOI: 10.1007/s00223-016-0165-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 06/15/2016] [Indexed: 12/01/2022]
Abstract
Pseudovitamin D deficiency is the consequence of a genetic defect in the CYP27B1 gene resulting in diminished or absent conversion of 25-hydroxyvitamin D3 (25-(OH)D3) into 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and leads to growth retardation and rickets, usually in the first 2 years of life. DNA obtained from human leucocytes from a patient suspected of pseudovitamin D deficiency and her healthy parents was sequenced for a genetic defect in the CYP27B1 gene. In silico analyses on the mutations were performed using online available software. The 1α-hydroxylase activity of the patient, her parents, and a sample derived from a mixed buffy coat of healthy blood donors was measured by culturing peripheral blood mononuclear cells with 25-(OH)D3 and measuring 1,25-(OH)2D3 production. DNA sequencing of the patient suspected of pseudovitamin D deficiency revealed compound heterozygosity in the CYP27B1 gene for a (c413G>T) mutation in exon 3 (R138L) and a (c1232G>A) mutation in exon 8 (C411Y). In silico analyses confirmed that mutations at these positions are probably damaging for the protein since the amino acids are situated in a highly conserved region. In vitro analyses showed a nearly absent 1α-hydroxylase activity in the patient compared to the healthy blood donors. Her healthy parents each of whom carried one of the mutations also had compromised conversion of 25-(OH)D3 into 1,25-(OH)2D3 in peripheral blood mononuclear cells, being only marginally higher than in the patient. We discovered novel compound heterozygous mutations in the CYP27B1 gene in a young girl presenting with pseudovitamin D-deficient rickets, leading to severely decreased 1,25-(OH)2D3 production. Furthermore, both heterozygous parents showed a diminished 1α-hydroxylase activity.
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Affiliation(s)
- W Nadia H Koek
- Department of Internal Medicine, Erasmus MC, Po. Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - M Carola Zillikens
- Department of Internal Medicine, Erasmus MC, Po. Box 2040, 3000 CA, Rotterdam, The Netherlands.
| | - Bram C J van der Eerden
- Department of Internal Medicine, Erasmus MC, Po. Box 2040, 3000 CA, Rotterdam, The Netherlands
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31
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Cho JH, Kang E, Kim GH, Lee BH, Choi JH, Yoo HW. Long-term clinical outcome and the identification of homozygous CYP27B1 gene mutations in a patient with vitamin D hydroxylation-deficient rickets type 1A. Ann Pediatr Endocrinol Metab 2016; 21:169-173. [PMID: 27777911 PMCID: PMC5073165 DOI: 10.6065/apem.2016.21.3.169] [Citation(s) in RCA: 4] [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: 05/26/2016] [Revised: 07/03/2016] [Accepted: 07/28/2016] [Indexed: 11/20/2022] Open
Abstract
Vitamin D hydroxylation-deficient rickets type 1A (VDDR1A) is an autosomal recessively-inherited disorder caused by mutations in CYP27B1 encoding the 1α-hydroxylase enzyme. We report on a female patient with VDDR1A who presented with hypocalcemic seizure at the age of 13 months. The typical clinical and biochemical features of VDDR1A were found, such as hypocalcemia, increased alkaline phosphatase, secondary hyperparathyroidism and normal 25-hydroxyvitamin D3 (25(OH)D3). Radiographic images of the wrist showed metaphyseal widening with cupping and fraying of the ulna and distal radius, suggesting rickets. A mutation analysis of the CYP27B1 gene identified a homozygous mutation of c.589+1G>A in the splice donor site in intron 3, which was known to be pathogenic. Since that time, the patient has been under calcitriol and calcium treatment, with normal growth and development. During the follow-up period, she did not develop genu valgum, scoliosis, or nephrocalcinosis.
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Affiliation(s)
- Ja Hyang Cho
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Eungu Kang
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Gu-Hwan Kim
- Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Beom Hee Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Jin-Ho Choi
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
| | - Han-Wook Yoo
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea
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Füchtbauer L, Brusgaard K, Ledaal P, Frost M, Frederiksen AL. Case report: vitamin D-dependent rickets type 1 caused by a novel CYP27B1 mutation. Clin Case Rep 2015; 3:1012-6. [PMID: 26734137 PMCID: PMC4693699 DOI: 10.1002/ccr3.406] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/17/2015] [Accepted: 08/27/2015] [Indexed: 01/31/2023] Open
Abstract
Vitamin D‐dependent rickets type 1 VDDR‐1 is a recessive inherited disorder with impaired activation of vitamin D, caused by mutations in CYP27B1. We present long‐time follow‐up of a case with a novel mutation including high‐resolution peripheral quantitative computed tomography of the bone. Adequate treatment resulted in a normalized phenotype.
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Affiliation(s)
- Laila Füchtbauer
- Department of Endocrinology Sahlgrenska Universitetssjukhuset Gothenburg Sweden
| | - Klaus Brusgaard
- Department of Clinical Genetics Odense University Hospital Odense Denmark
| | - Pål Ledaal
- Pediatric Department Sygehus Sønderjylland Sønderborg Denmark
| | - Morten Frost
- Department of Endocrinology M Odense University Hospital Odense Denmark
| | - Anja L Frederiksen
- Department of Clinical Genetics Odense University Hospital Odense Denmark
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