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Gefen AM, Zaritsky JJ. Review of childhood genetic nephrolithiasis and nephrocalcinosis. Front Genet 2024; 15:1381174. [PMID: 38606357 PMCID: PMC11007102 DOI: 10.3389/fgene.2024.1381174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 03/04/2024] [Indexed: 04/13/2024] Open
Abstract
Nephrolithiasis (NL) is a common condition worldwide. The incidence of NL and nephrocalcinosis (NC) has been increasing, along with their associated morbidity and economic burden. The etiology of NL and NC is multifactorial and includes both environmental components and genetic components, with multiple studies showing high heritability. Causative gene variants have been detected in up to 32% of children with NL and NC. Children with NL and NC are genotypically heterogenous, but often phenotypically relatively homogenous, and there are subsequently little data on the predictors of genetic childhood NL and NC. Most genetic diseases associated with NL and NC are secondary to hypercalciuria, including those secondary to hypercalcemia, renal phosphate wasting, renal magnesium wasting, distal renal tubular acidosis (RTA), proximal tubulopathies, mixed or variable tubulopathies, Bartter syndrome, hyperaldosteronism and pseudohyperaldosteronism, and hyperparathyroidism and hypoparathyroidism. The remaining minority of genetic diseases associated with NL and NC are secondary to hyperoxaluria, cystinuria, hyperuricosuria, xanthinuria, other metabolic disorders, and multifactorial etiologies. Genome-wide association studies (GWAS) in adults have identified multiple polygenic traits associated with NL and NC, often involving genes that are involved in calcium, phosphorus, magnesium, and vitamin D homeostasis. Compared to adults, there is a relative paucity of studies in children with NL and NC. This review aims to focus on the genetic component of NL and NC in children.
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Affiliation(s)
- Ashley M. Gefen
- Phoenix Children’s Hospital, Department of Pediatrics, Division of Nephrology, Phoenix, AZ, United States
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2
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Schumann A, Schultheiss UT, Ferreira CR, Blau N. Clinical and biochemical footprints of inherited metabolic diseases. XIV. Metabolic kidney diseases. Mol Genet Metab 2023; 140:107683. [PMID: 37597335 DOI: 10.1016/j.ymgme.2023.107683] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/11/2023] [Accepted: 08/11/2023] [Indexed: 08/21/2023]
Abstract
Kidney disease is a global health burden with high morbidity and mortality. Causes of kidney disease are numerous, extending from common disease groups like diabetes and arterial hypertension to rare conditions including inherited metabolic diseases (IMDs). Given its unique anatomy and function, the kidney is a target organ in about 10% of known IMDs, emphasizing the relevant contribution of IMDs to kidney disease. The pattern of injury affects all segments of the nephron including glomerular disease, proximal and distal tubular damage, kidney cyst formation, built-up of nephrocalcinosis and stones as well as severe malformations. We revised and updated the list of known metabolic etiologies associated with kidney involvement and found 190 relevant IMDs. This represents the 14th of a series of educational articles providing a comprehensive and revised list of metabolic differential diagnoses according to system involvement.
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Affiliation(s)
- Anke Schumann
- Department of General Paediatrics, Adolescent Medicine and Neonatology, Medical Center-University of Freiburg, Faculty of Medicine, Freiburg, Germany.
| | - Ulla T Schultheiss
- Department of Medicine IV, Nephrology and Primary Care, Faculty of Medicine, and Medical Center, University of Freiburg, Institute of Genetic Epidemiology, Freiburg, Germany.
| | - Carlos R Ferreira
- National Human Genome Research Institute, National Institutes of Health, Bethesda, USA.
| | - Nenad Blau
- Division of Metabolism, University Children's Hospital, Zürich, Switzerland.
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3
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Kluck R, Müller S, Jagodzinski C, Hohenfellner K, Büscher A, Kemper MJ, Oh J, Billing H, Thumfart J, Weber LT, Acham-Roschitz B, Arbeiter K, Tönshoff B, Hagenberg M, Kanzelmeyer N, Pavičić L, Haffner D, Zivicnjak M. Body growth, upper arm fat area, and clinical parameters in children with nephropathic cystinosis compared with other pediatric chronic kidney disease entities. J Inherit Metab Dis 2022; 45:192-202. [PMID: 34989402 DOI: 10.1002/jimd.12473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/30/2021] [Accepted: 01/04/2022] [Indexed: 11/12/2022]
Abstract
Children with infantile nephropathic cystinosis (INC), an inherited lysosomal storage disease resulting in cystine accumulation in all body cells, are prone to progressive chronic kidney disease (CKD), impaired growth and reduced weight gain; however, systematic anthropometric analyses are lacking. In this prospective multicenter study we investigated linear growth, body proportion, body mass index (BMI), upper arm fat area (UFA) and biochemical parameters in 43 pediatric INC patients with CKD stages 1 to 5 and 49 age-matched CKD controls, with 193 annual measurements. INC patients showed more impaired height than CKD controls (-1.8 vs -0.7 z-score; P < .001), despite adequate cysteamine therapy, treatment for Fanconi syndrome and more frequent use of growth hormone. Only the youngest INC patients shared the same body pattern with CKD controls characterized by preferential impairment of leg length and rather preserved trunk length. In late-prepuberty, body pattern changed only in INC patients due to improved leg growth and more impaired trunk length. Mean UFA z-score in INC patients was slightly reduced in early childhood and progressively decreased thereafter reaching -0.8 z-score in adolescence, while CKD controls showed a steady increase in standardized BMI and UFA especially during adolescent age. Menarche in female INC patients was significantly delayed compared to CKD controls. Our data indicate that with age and progression of disease, pediatric INC patients undergo unique changes of body growth and fat stores that are distinct from those with CKD stemming from other causes, suggesting other factors apart from CKD to contribute to this development. Pediatric patients with infantile nephropathic cystinosis display more severe impaired linear growth than other peer CKD patients, despite of cysteamine treatment, supplementation for Fanconi syndrome, and more frequent use of growth hormone, with a distinct change of body proportions and overall lower body fat.
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Affiliation(s)
- Rika Kluck
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Children's Hospital, Hannover, Germany
| | - Sophia Müller
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Children's Hospital, Hannover, Germany
| | - Celina Jagodzinski
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Children's Hospital, Hannover, Germany
| | | | - Anja Büscher
- Department of Pediatrics II, University Hospital Essen, Essen, Germany
| | - Markus J Kemper
- Asklepios Medical School, Asklepios Hospital North-Heidberg, Hamburg, Germany
| | - Jun Oh
- Division of Pediatric Nephrology, University Children's Hospital Hamburg, Hamburg, Germany
| | - Heiko Billing
- Clinic for Pediatric and Adolescent Medicine, RHK Clinic Ludwigsburg, Ludwigsburg, Germany
| | - Julia Thumfart
- Department of Pediatric Gastroenterology, Nephrology and Metabolic Diseases, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Lutz T Weber
- Division of Pediatric Nephrology, Children's and Adolescents' Hospital, University of Cologne, Faculty of Medicine and University Hospital, Cologne, Germany
| | | | - Klaus Arbeiter
- Division of Pediatric Nephrology and Gastroenterology, Medical University, Vienna, Austria
| | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Martina Hagenberg
- Department of Pediatrics, Hospital St. Elisabeth and St. Barbara, Halle (Saale), Germany
| | - Nele Kanzelmeyer
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Children's Hospital, Hannover, Germany
| | | | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Children's Hospital, Hannover, Germany
| | - Miroslav Zivicnjak
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Children's Hospital, Hannover, Germany
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4
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Hamed DH, Halim RMA, El Attar MM, Soliman NA, Osman HM. Pulmonary dysfunction in children with Cystinosis: single center study, original article. EGYPTIAN PEDIATRIC ASSOCIATION GAZETTE 2022. [DOI: 10.1186/s43054-022-00098-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Cystinosis is a rare autosomal recessive disorder involving lysosomal storage of the amino acid cystine due to a defect in the membrane transport protein, cystinosin. The disease results in intracellular accumulation of cystine in all organs and tissues.
Pulmonary complications targeting the respiratory system occurs commonly in adults who have not received lifelong cysteamine therapy. The respiratory insufficiency is fatal at adulthood. However, little is known about the pulmonary dysfunction in children.
The study included 15 nephropathic cystinosis children to evaluate the pulmonary complications through detailed history taking, clinical examination, chest radiograph and Pulmonary function test (Impulse oscillometry {IOS}).
Results
Out of the cohort of 15 cystinosis patients, 13 patients did not show symptoms suggestive of chest affection. While 1 patient had recurrent Aspiration and 1 patient had history of pneumonia requiring hospital admission. All patients showed normal respiratory rate for age, normal breath sound and normal Chest X-ray finding apart from conical chest configuration.
IOS done showed small airway disease in 12 patients, decreased compliance in 2 patients, while only 1patient had normal IOS.
Conclusion
Small airway affection was detected in most of cystinosis children by means of IOS in spite of the absence of chest manifestations and suggestive history which highlight the importance of respiratory assessment and follow up of cystinosis patients not only by history, and examination but most important pulmonary function tests.
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Florenzano P, Ferreira C, Nesterova G, Roberts MS, Tella SH, de Castro LF, Brown SM, Whitaker A, Pereira RC, Bulas D, Gafni RI, Salusky IB, Gahl WA, Collins MT. Skeletal Consequences of Nephropathic Cystinosis. J Bone Miner Res 2018; 33:1870-1880. [PMID: 29905968 DOI: 10.1002/jbmr.3522] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 05/18/2018] [Accepted: 06/06/2018] [Indexed: 01/03/2023]
Abstract
Nephropathic cystinosis is a rare lysosomal storage disorder. Patients present in the first year of life with renal Fanconi syndrome that evolves to progressive chronic kidney disease (CKD). Despite the multiple risk factors for bone disease, the frequency and severity of skeletal disorders in nephropathic cystinosis have not been described. We performed systematic bone and mineral evaluations of subjects with cystinosis seen at the NIH (n = 30), including history and physical examination, serum and urine biochemistries, DXA, vertebral fracture assessment, skeletal radiographs, and renal ultrasound. Additionally, histomorphometric analyses are reported on six subjects seen at the UCLA Bone and Mineral Metabolism Clinic. In NIH subjects, mean age was 20 years (range, 5 to 44 years), 60% were CKD stages G1 to G4, and 40% had a renal transplant. Mean bone mineral density (BMD) Z-scores were decreased in the femoral neck, total hip, and 1/3 radius (p < 0.05). Low bone mass at one or more sites was present in 46% of subjects. Twenty-seven percent of subjects reported one or more long bone fractures. Thirty-two percent of subjects had incidental vertebral fractures, which were unrelated to transplant status. Long-bone deformity/bowing was present in 64%; 50% had scoliosis. Diffuse osteosclerosis was present in 21% of evaluated subjects. Risk factors included CKD, phosphate wasting, hypercalciuria, secondary hyperparathyroidism, hypovitaminosis D, male hypogonadism, metabolic acidosis, and glucocorticoid/immunosuppressive therapy. Sixty-one percent of the non-transplanted subjects had ultrasonographic evidence of nephrocalcinosis or nephrolithiasis. Histomorphometric analyses showed impaired mineralization in four of six studied subjects. We conclude that skeletal deformities, decreased bone mass, and vertebral fractures are common and relevant complications of nephropathic cystinosis, even before renal transplantation. Efforts to minimize risk factors for skeletal disease include optimizing mineral metabolism and hormonal status, combined with monitoring for nephrocalcinosis/nephrolithiasis. © 2018 This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Pablo Florenzano
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA.,Endocrinology Department, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Carlos Ferreira
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Galina Nesterova
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Mary Scott Roberts
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sri Harsha Tella
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Luis Fernandez de Castro
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Sydney M Brown
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Adom Whitaker
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Renata C Pereira
- Division of Nephrology, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Dorothy Bulas
- Division of Radiology, Children's National Health System, Washington, DC, USA
| | - Rachel I Gafni
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Isidro B Salusky
- Division of Nephrology, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Michael T Collins
- Section on Skeletal Disorders and Mineral Homeostasis, National Institutes of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA
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6
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Alexander RT, Cordat E, Chambrey R, Dimke H, Eladari D. Acidosis and Urinary Calcium Excretion: Insights from Genetic Disorders. J Am Soc Nephrol 2016; 27:3511-3520. [PMID: 27468975 DOI: 10.1681/asn.2016030305] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibition of calcium transport processes within the renal tubule. The mechanisms whereby acid alters the integrity and stability of bone have been examined extensively in the published literature. Here, after briefly reviewing this literature, we consider the effects of acid on calcium transport in the renal tubule and then discuss why not all gene defects that cause renal tubular acidosis are associated with hypercalciuria and nephrocalcinosis.
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Affiliation(s)
- R Todd Alexander
- Departments of Pediatrics and .,Physiology, University of Alberta, Edmonton, Canada
| | | | - Régine Chambrey
- Institut National de la Santé et de la Recherche Médicale U970, Paris Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Demark; and
| | - Dominique Eladari
- Institut National de la Santé et de la Recherche Médicale U970, Paris Centre de Recherche Cardiovasculaire, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Department of Physiologie, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
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7
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Elmonem MA, Veys KR, Soliman NA, van Dyck M, van den Heuvel LP, Levtchenko E. Cystinosis: a review. Orphanet J Rare Dis 2016; 11:47. [PMID: 27102039 PMCID: PMC4841061 DOI: 10.1186/s13023-016-0426-y] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 04/15/2016] [Indexed: 01/01/2023] Open
Abstract
Cystinosis is the most common hereditary cause of renal Fanconi syndrome in children. It is an autosomal recessive lysosomal storage disorder caused by mutations in the CTNS gene encoding for the carrier protein cystinosin, transporting cystine out of the lysosomal compartment. Defective cystinosin function leads to intra-lysosomal cystine accumulation in all body cells and organs. The kidneys are initially affected during the first year of life through proximal tubular damage followed by progressive glomerular damage and end stage renal failure during mid-childhood if not treated. Other affected organs include eyes, thyroid, pancreas, gonads, muscles and CNS. Leucocyte cystine assay is the cornerstone for both diagnosis and therapeutic monitoring of the disease. Several lines of treatment are available for cystinosis including the cystine depleting agent cysteamine, renal replacement therapy, hormonal therapy and others; however, no curative treatment is yet available. In the current review we will discuss the most important clinical features of the disease, advantages and disadvantages of the current diagnostic and therapeutic options and the main topics of future research in cystinosis.
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Affiliation(s)
- Mohamed A Elmonem
- Department of Pediatric Nephrology & Growth and Regeneration, University Hospitals Leuven & KU Leuven, UZ Herestraat 49-3000, Leuven, Belgium.,Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Koenraad R Veys
- Department of Pediatric Nephrology & Growth and Regeneration, University Hospitals Leuven & KU Leuven, UZ Herestraat 49-3000, Leuven, Belgium
| | - Neveen A Soliman
- Department of Pediatrics, Center of Pediatric Nephrology and Transplantation (CPNT), Faculty of Medicine, Cairo University, Cairo, Egypt.,EGORD, Egyptian group of orphan renal diseases, Cairo, Egypt
| | - Maria van Dyck
- Department of Pediatric Nephrology & Growth and Regeneration, University Hospitals Leuven & KU Leuven, UZ Herestraat 49-3000, Leuven, Belgium
| | - Lambertus P van den Heuvel
- Department of Pediatric Nephrology & Growth and Regeneration, University Hospitals Leuven & KU Leuven, UZ Herestraat 49-3000, Leuven, Belgium.,Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elena Levtchenko
- Department of Pediatric Nephrology & Growth and Regeneration, University Hospitals Leuven & KU Leuven, UZ Herestraat 49-3000, Leuven, Belgium.
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Nesterova G, Gahl WA. Cystinosis: the evolution of a treatable disease. Pediatr Nephrol 2013; 28:51-9. [PMID: 22903658 PMCID: PMC3505515 DOI: 10.1007/s00467-012-2242-5] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 06/07/2012] [Accepted: 06/08/2012] [Indexed: 11/01/2022]
Abstract
Cystinosis is a rare autosomal recessive disorder involving lysosomal storage of the amino acid cystine due to a defect in the membrane transport protein, cystinosin. Since the introduction of kidney transplants and the availability of cystine-depleting medical therapy, this previously fatal disease was transformed into a treatable disorder. Renal allografts and medical therapy targeting the basic metabolic defect have altered the natural hisotry of cystinosis so drastically that patients have a life expectancy extending past 50 years. Consequently, early diagnosis and appropriate therapy are critically important. In this article, we offer a review of the manifestations of cystinosis, including the proximal tubular dysfunction of renal Fanconi syndrome, and discuss the prevention and treatment of the disorder's systemic complications. We focus on the nephropathic forms of cystinosis, aiming to assist nephrologists and other physicians to develop early recognition and appropriate management of cystinosis patients.
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Affiliation(s)
- Galina Nesterova
- NHGRI, Medical Biochemical Genetic Section, National Institutes of Health, Bethesda, MD, USA.
| | - William A. Gahl
- NHGRI, Medical Biochemical Genetic Section, National Institutes of Health, Bethesda, MD USA
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9
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Cystinosis: practical tools for diagnosis and treatment. Pediatr Nephrol 2011; 26:205-15. [PMID: 20734088 PMCID: PMC3016220 DOI: 10.1007/s00467-010-1627-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Revised: 07/05/2010] [Accepted: 07/07/2010] [Indexed: 02/07/2023]
Abstract
Cystinosis is the major cause of inherited Fanconi syndrome, and should be suspected in young children with failure to thrive and signs of renal proximal tubular damage. The diagnosis can be missed in infants, because not all signs of renal Fanconi syndrome are present during the first months of life. In older patients cystinosis can mimic idiopathic nephrotic syndrome due to focal and segmental glomerulosclerosis. Measuring elevated white blood cell cystine content is the corner stone for the diagnosis. The diagnosis is confirmed by molecular analysis of the cystinosin gene. Corneal cystine crystals are invariably present in all patients with cystinosis after the age of 1 year. Treatment with the cystine depleting drug cysteamine should be initiated as soon as possible and continued lifelong to prolong renal function survival and protect extra-renal organs. This educational feature provides practical tools for the diagnosis and treatment of cystinosis.
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Nesterova G, Gahl W. Nephropathic cystinosis: late complications of a multisystemic disease. Pediatr Nephrol 2008; 23:863-78. [PMID: 18008091 DOI: 10.1007/s00467-007-0650-8] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 09/24/2007] [Accepted: 09/24/2007] [Indexed: 11/29/2022]
Abstract
Cystinosis is a rare autosomal recessive disorder due to impaired transport of cystine out of cellular lysosomes. Its estimated incidence is 1 in 100,000 live births. End-stage renal disease (ESRD) is the most prominent feature of cystinosis and, along with dehydration and electrolyte imbalance due to renal tubular Fanconi syndrome, has accounted for the bulk of deaths from this disorder. Prior to renal transplantation and cystine-depleting therapy with cysteamine for children with nephropathic cystinosis, their lifespan was approximately 10 years. Now, cystinotic patients have survived through their fifth decade, but the unremitting accumulation of cystine has created significant non-renal morbidity and mortality. In this article we review the classic presentation of nephropathic cystinosis and the natural history, diagnosis, and treatment of the disorder's systemic involvement. We also emphasize the role of oral cysteamine therapy in preventing the late complications of cystinosis.
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Affiliation(s)
- Galina Nesterova
- Section on Human Biochemical Genetics, Human Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-1851, USA
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11
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Wamelink MMC, Struys EA, Jansen EEW, Levtchenko EN, Zijlstra FSM, Engelke U, Blom HJ, Jakobs C, Wevers RA. Sedoheptulokinase deficiency due to a 57-kb deletion in cystinosis patients causes urinary accumulation of sedoheptulose: elucidation of the CARKL gene. Hum Mutat 2008; 29:532-6. [PMID: 18186520 DOI: 10.1002/humu.20685] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The most common mutation in the nephropathic cystinosis (CTNS) gene is a homozygous 57-kb deletion that also includes an adjacent gene carbohydrate kinase-like (CARKL). The latter gene encodes a protein that is predicted to function as a carbohydrate kinase. Cystinosis patients with the common 57-kb deletion had strongly elevated urinary concentrations of sedoheptulose (28-451 mmol/mol creatinine; controls and other cystinosis patients <9) and erythritol (234-1110 mmol/mol creatinine; controls and other cystinosis patients <148). Enzyme studies performed on fibroblast homogenates derived from patients carrying the 57-kb deletion revealed 80% reduction in their sedoheptulose phosphorylating activity compared to cystinosis patients with other mutations and controls. This indicates that the CARKL-encoded protein, sedoheptulokinase (SHK), is responsible for the reaction: sedoheptulose + ATP --> sedoheptulose-7-phosphate + ADP and that deletion of CARKL causes urinary accumulation of sedoheptulose and erythritol.
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Affiliation(s)
- Mirjam M C Wamelink
- Department of Clinical Chemistry, Metabolic Unit, VU University Medical Center, Amsterdam, The Netherlands.
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12
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Ueda M, O'Brien K, Rosing DR, Ling A, Kleta R, McAreavey D, Bernardini I, Gahl WA. Coronary artery and other vascular calcifications in patients with cystinosis after kidney transplantation. Clin J Am Soc Nephrol 2006; 1:555-62. [PMID: 17699259 DOI: 10.2215/cjn.01431005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cystinosis, an autosomal recessive disorder of lysosomal cystine accumulation, results from mutations in the CTNS gene that encodes the lysosomal cystine transporter, cystinosin. Renal tubular Fanconi syndrome occurs in infancy, followed by rickets, growth retardation, photophobia, and renal failure, which requires renal transplantation at approximately 10 yr of age. Treatment with cysteamine decreases cellular cystine levels, retards renal deterioration, and allows for normal growth. Patients with a history of inadequate cystine depletion therapy may survive, after renal transplantation, into the third to fifth decades but will experience other, extrarenal complications of the disease. Routine chest and head computed tomography scans of 41 posttransplantation patients with cystinosis were reviewed for vascular calcification. The radiologic procedures had been performed to examine lung and brain parenchyma, so there was little ascertainment bias. Thirteen of the 41 patients had vascular calcification, including 11 with coronary artery calcification. One 25-yr-old man required three-vessel coronary artery bypass graft surgery. There were no significant differences between the 13 patients with calcification and the 28 without calcification in the following parameters: Time on dialysis, frequency of transplantation, hypertension, hypercholesterolemia, homozygosity for the 57-kb deletion in CTNS, serum creatinine, and calcium-phosphate product. However, the finding of vascular calcification correlated directly with duration of life without cysteamine therapy and inversely with duration of life under good cystine-depleting therapy. The accumulation of intracellular cystine itself maybe a risk factor for vascular calcifications, and older patients with cystinosis should be screened for this complication.
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Affiliation(s)
- Masako Ueda
- Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892-1851, USA
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Abstract
We report the excellent clinical outcomes of siblings with nephropathic cystinosis treated diligently with cysteamine starting at 20 months and 2 months of age. Now 15 and 8 years old, they have glomerular filtration rates of 78 and 105 mL/min/1.73m 2 , respectively. These cases illustrate the critical importance of early diagnosis and treatment.
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14
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Affiliation(s)
- William A Gahl
- Heritable Disorders Branch, National Institute of Child Health and Human Development, Bethesda, Md 20892-1830, USA.
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Touchman JW, Anikster Y, Dietrich NL, Maduro VV, McDowell G, Shotelersuk V, Bouffard GG, Beckstrom-Sternberg SM, Gahl WA, Green ED. The genomic region encompassing the nephropathic cystinosis gene (CTNS): complete sequencing of a 200-kb segment and discovery of a novel gene within the common cystinosis-causing deletion. Genome Res 2000; 10:165-73. [PMID: 10673275 PMCID: PMC310836 DOI: 10.1101/gr.10.2.165] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nephropathic cystinosis is an autosomal recessive disorder caused by the defective transport of cystine out of lysosomes. Recently, the causative gene (CTNS) was identified and presumed to encode an integral membrane protein called cystinosin. Many of the disease-associated mutations in CTNS are deletions, including one >55 kb in size that represents the most common cystinosis allele encountered to date. In an effort to determine the precise genomic organization of CTNS and to gain sequence-based insight about the DNA within and flanking cystinosis-associated deletions, we mapped and sequenced the region of human chromosome 17p13 encompassing CTNS. Specifically, a bacterial artificial chromosome (BAC)-based physical map spanning CTNS was constructed by sequence-tagged site (STS)-content mapping. The resulting BAC contig provided the relative order of 43 STSs. Two overlapping BACs, which together contain all of the CTNS exons as well as extensive amounts of flanking DNA, were selected and subjected to shotgun sequencing. A total of 200,237 bp of contiguous, high-accuracy sequence was generated. Analysis of the resulting data revealed a number of interesting features about this genomic region, including the long-range organization of CTNS, insight about the breakpoints and intervening DNA associated with the common cystinosis-causing deletion, and structural information about five genes neighboring CTNS (human ortholog of rat vanilloid receptor subtype 1 gene, CARKL, TIP-1, P2X5, and HUMINAE). In particular, sequence analysis detected the presence of a novel gene (CARKL) residing within the most common cystinosis-causing deletion. This gene encodes a previously unknown protein that is predicted to function as a carbohydrate kinase. Interestingly, both CTNS and CARKL are absent in nearly half of all cystinosis patients (i.e., those homozygous for the common deletion). [The sequence data described in this paper have been submitted to the GenBank data library under accession nos. AF168787 and AF163573.]
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Affiliation(s)
- J W Touchman
- NIH Intramural Sequencing Center, National Institutes of Health, Gaithersburg, Maryland 20877, USA
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Assadi FK, Mullin JJ, Beckman DA. Evaluation of the reproductive and developmental safety of cysteamine in the rat: effects on female reproduction and early embryonic development. TERATOLOGY 1998; 58:88-95. [PMID: 9802188 DOI: 10.1002/(sici)1096-9926(199809/10)58:3/4<88::aid-tera4>3.0.co;2-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cystinosis is an autosomal recessive metabolic disease in which the amino acid cystine accumulates in lysosomes due to a defect in lysosomal cystine transport. Cystinosis in infancy is associated with poor growth, muscle wastage, and death at about age 10 due to kidney failure. Treatment with cysteamine and kidney transplantation enables cystinotic girls to reach reproductive age and to be healthy enough to permit pregnancy. It is not known whether exposure to cysteamine will have adverse effects on reproduction in the human. It is also possible that some of the complications seen in cystinotic children could be avoided if a pregnant woman carrying a cystinotic fetus were given cysteamine. However, this treatment is not likely to occur until therapeutic exposures to cysteamine are judged to present no increased risk to the human fetus. As part of a larger investigation assessing the reproductive and developmental safety of cysteamine (as phosphocysteamine) using the rat, the two studies reported herein were performed. The first, a dose-finding study, led to the selection of 150 mg/kg/day as the highest dose of cysteamine used for the second and primary focus of this report. The second study involved the exposure of female rats to cysteamine from premating through day 6.5 postconception and assessment of female fertility and early embryonic development. Cysteamine was administered orally in doses of 0, 37.5, 75, 100, or 150 mg/kg/day. There were no clinical signs of maternal toxicity during the exposures of 2 to 5 weeks before successful mating. Animals in the 150 mg/kg/day group experienced a nonsignificant decrease in body weight gain during pregnancy to day 6.5 postconception, a significant increase in liver and spleen weights, and a significant increase in days to coitus--suggesting that a low level of toxicity was manifested. However, there were no adverse effects on reproductive performance with respect to conception and early embryonic development.
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Affiliation(s)
- F K Assadi
- Department of Pediatrics, Alfred I. duPont Hospital for Children, Wilmington, Delaware 19899, USA
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Abstract
The reproductive and developmental safety of cysteamine has become an important issue to children with cystinosis because renal transplants and treatment with cysteamine reduce the complications associated with cystinosis and increase the lifespan of the affected children. In addition, there is the potential to decrease the severity or the incidence of renal Fanconi syndrome with administration of cysteamine to pregnant women carrying fetuses with cystinosis, and to ease significantly the burden of this disease throughout their lives. If cysteamine increases significantly the risk of fetal death, growth retardation or birth defects at doses used to treat women with cystinosis, treatment of the affected female should cease during pregnancy and would not be considered for fetal treatment. The goal of this study was to assess the developmental safety of exposure in utero to cysteamine in the rat. Pregnant rats were given cysteamine (as phosphocysteamine) from day 6.5 through day 18.5 postconception and fetuses were assessed for survival, growth, and structural abnormalities on day 20.5. Cysteamine was administered orally in doses of 0, 37.5, 75, 100, or 150 mg/kg/day. Cysteamine produced dose-dependent developmental toxicity with an apparent no adverse effect observed level of 75 mg/kg/day. Specific malformations were associated with this effect (cleft palate, kyphosis), as well as intrauterine growth retardation and fetal death at 100-150 mg/kg/day, without signs of maternal toxicity. Investigations continue into the mechanism for the developmental toxicity of cysteamine.
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Affiliation(s)
- D A Beckman
- Division of Developmental Biology, Nemours Research Programs, Alfred I. duPont Hospital for Children, Wilmington, Delaware 19899, USA.
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