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Shamsian BS, Momtazmanesh N, Saneifard H, Tabatabaei SMTH, Jafari M, Pour ZK, Al-Hussieni KJMR, Jamee M, Kamfar S. Allogenic hematopoietic stem cell transplantation in an Iranian patient with osteopetrosis caused by carbonic anhydrase II deficiency: A case report. Pediatr Transplant 2024; 28:e14689. [PMID: 38655726 DOI: 10.1111/petr.14689] [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: 12/22/2023] [Accepted: 12/22/2023] [Indexed: 04/26/2024]
Abstract
BACKGROUND Osteopetrosis is a group of geneticall heterogeneous disorders resulting from impaired osteoclast function and bone resorption. The identification of specific genetic mutations can yield important prognostic and therapeutic implications. Herein, we present the diagnosis and successful application of hematopoietic stem cell transplantation (HSCT) in a patient with osteopetrosis caused by carbonic anhydrase II deficiency (Intermediate osteopetrosis). CASE PRESENTATION Herein, we describe a 2.5-year-old male patient born to consanguineous parents who presented at 8-month-old with hydrocephaly, brain shunt, and developmental delay. Later at 9 months old, he was found to have eye disorder such as nystagmus, fracture of the elbow, abnormal skeletal survey, normal cell blood count (CBC), and severe hypocellularity in the bone marrow. Further evaluation showed renal tubular acidosis type 2. Whole-exome sequencing revealed a pathogenic homozygous variant in intron 2 of the carbonic anhydrase 2 gene (CA2) gene (c.232 + 1 G>T). The diagnosis of intermediate autosomal recessive osteopetrosis was established, and allogenic HSCT from his mother, a full-matched related donor (MRD), was planned. The conditioning regimen included Busulfan, Fludarabine, and Rabbit anti-thymocyte globulin. Cyclosporine and Mycophenolate Mofetil were used for graft-versus-host-disease prophylaxis. He Engrafted on day +13, and 95% chimerism was achieved. He is currently doing well without immunosuppressive therapy, now 12 months post HSCT, with normal calcium level and improving visual quality and FISH analysis revealed complete donor chimerism. DISCUSSION HSCT could be a promising curative treatment for intermediate osteopetrosis and can provide long-term survival. Ongoing challenges in various aspects of HSCT remain to be addressed.
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Affiliation(s)
- Bibi Shahin Shamsian
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nader Momtazmanesh
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hedyeh Saneifard
- Pediatric Endocrinology and Metabolism Department, Faculty of Medicine, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mohammadreza Jafari
- Student Research Committee, Alborz University of Medical Sciences, Karaj, Iran
| | - Zahra Khafaf Pour
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mahnaz Jamee
- Pediatric Nephrology Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sharareh Kamfar
- Pediatric Congenital Hematologic Disorders Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Schulz A, Moshous D. Hematopoietic stem cell transplantation, a curative approach in infantile osteopetrosis. Bone 2023; 167:116634. [PMID: 36470372 DOI: 10.1016/j.bone.2022.116634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022]
Abstract
Most patients with osteopetrosis (OPT) can be causally and curatively treated with allogeneic hematopoietic stem cell transplantation (HSCT) because osteoclasts are derived from the HSC. However, HSCT is contraindicated in some forms of OPT, namely OPT with neurodegeneration (in all patients with OSTM1 and about half of patients with CLCN7 mutations) and OPT caused by an osteoblast defect (patients with RANKL mutations). HSCT for OPT risks serious side effects, such as transplant failure, venous occlusive disease, pulmonary hypertension, and hypercalcemic crises. Nevertheless, the success rate of HSCT has improved significantly in recent decades. This applies, in particular, to HSCT from non-HLA compatible (haploidentical) donors. Therefore, nowadays an HSCT can be discussed for intermediate OPT forms. After a successful HSCT, most patients have very good quality of life, but about two-thirds are visually impaired, and in rarer cases show motor and neurological disabilities. Early diagnosis, further improvements in transplantation procedures, and advances to improve quality-of-life after transplantation are challenges for the future.
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Affiliation(s)
- Ansgar Schulz
- Department of Paediatrics, University Medical Center Ulm, Eythstr. 24, D 89075 Ulm, Germany.
| | - Despina Moshous
- Department of Pediatric Immunology, Hematology and Rheumatology, Hôpital Universitaire Necker-Enfants Malades, AP-HP, Université Paris Cité, 149, rue de Sèvres, 75015 Paris, France.
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Alotaibi Q, Dighe M, Aldaihani S. The clinical features of OSTM1-associated malignant infantile osteopetrosis: A retrospective, single-center experience over one decade. Am J Med Genet A 2023; 191:459-468. [PMID: 36369659 DOI: 10.1002/ajmg.a.63042] [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: 05/10/2022] [Revised: 06/24/2022] [Accepted: 10/25/2022] [Indexed: 11/15/2022]
Abstract
Mutation in OSTM1 give rise to the rarest and most lethal subtype of malignant infantile osteopetrosis (MIOP), and an improved understanding of OSTM1-associated MIOP would help with informed decision-making regarding symptom management and early palliative care referral. This retrospective study describes the clinical and laboratory features of patients with a genetic diagnosis of OSTM1 MIOP made between January 2011 and December 2021 in the Department of Pediatrics, Al-Adan Hospital, Kuwait. Twenty-two children had confirmed homozygous deletion in OSTM1 (13 females, nine males). Consanguinity was reported in almost all parents. 72.7% were diagnosed before the age of two months, most commonly incidentally with a high clinical suspicion. All 22 patients developed upper respiratory symptoms, hepatosplenomegaly, poor feeding, and had severe developmental delay. 80% of patients developed pain and/or irritability, and 40.9% were diagnosed with primary seizures. Bone fractures developed in 27% of patients, most likely iatrogenic, and some patients had hernia and gum abnormalities. The mean survival was 10.9 months. The clinical presentation, symptomatology, and mortality of our cohort were compared with other cases of OSTM1 MIOP identified through a comperhensive search of the PubMed database. The findings conclude that OSTM1 MIOP is a multi-systemic disease with distinct clinical features, of which neurological complications are the most severe and include nociplastic pain and irritability. Although orthopedic complications influence the trajectory of most patients with other forms of osteopetrosis, OSTM1 MIOP is driven by its neurological complications. Hence, OSTM1 should be regarded as a neurodegenerative disease with osteopetrosis as a comorbidity that warrants early palliative care referral.
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Affiliation(s)
| | - Manjiri Dighe
- Pediatric Department, Aladan Hospital, Al-Masayel, Kuwait
| | - Saad Aldaihani
- Pediatric Department, Aladan Hospital, Al-Masayel, Kuwait
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Khromykh K, Dudnyk V, Korol T, Fedchishen O. MARBLE DISEASE (CASE REPORT). WIADOMOSCI LEKARSKIE (WARSAW, POLAND : 1960) 2023; 76:1694-1700. [PMID: 37622517 DOI: 10.36740/wlek202307127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
We present clinical case of marble disease in 5 yo girl. The management of this child was made in Vinnitsia Regional Children's Hospital (Vinnitsia, Ukraine). CBC, X-ray of bones, bone marrow biopsy, genetical testing, MRI of the brain and CT of the skull were done during this period. Marble disease is a very rare disease with very serious consequences, the prevention of which requires timely diagnosis and treatment, namely the prevention of infectious complications and early allogenic transplantation of stem cells. As it is a genetically determined disease, it is not possible to prevent the development of osteopetrosis. Genetic screening and proper treatment will allow the patient to lead an almost normal life.
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Affiliation(s)
| | - Veronika Dudnyk
- NATIONAL PIROGOV MEMORIAL MEDICAL UNIVERSITY, VINNYTSIA, UKRAINE
| | - Tetiana Korol
- NATIONAL PIROGOV MEMORIAL MEDICAL UNIVERSITY, VINNYTSIA, UKRAINE
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Vacher J. OSTM1 pleiotropic roles from osteopetrosis to neurodegeneration. Bone 2022; 163:116505. [PMID: 35902071 DOI: 10.1016/j.bone.2022.116505] [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: 06/07/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 11/28/2022]
Abstract
Autosomal recessive osteopetroses (ARO) are rare genetic skeletal disorders of high clinical and molecular heterogeneity with an estimated frequency of 1:250,000 worldwide. The manifestations are diverse and although individually rare, the various forms contribute to the prevalence of a significant number of affected individuals with considerable morbidity and mortality. Among the ARO classification, the most severe form is the autosomal recessive-5 (OPTB5) osteopetrosis (OMIM 259720) that results from homozygous mutation in the OSTM1 gene (607649). OSTM1 mutations account for approximately 5 % of instances of autosomal recessive osteopetrosis and lead to a highly debilitating form of the disease in infancy and death within the first few years of life (Sobacchi et al., 2013) [1].
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Affiliation(s)
- Jean Vacher
- Institut de Recherches Cliniques de Montréal (IRCM), 110 avenue des Pins Ouest, Montréal, Québec H2W 1R7, Canada; Département de Médecine, Université de Montréal, Montréal, Québec, Canada.
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Xu Y, Yu X, Huang M. A novel mutation in TNFRSF11A gene causes pediatric osteopetrosis: case report. BMC Surg 2021; 21:269. [PMID: 34049530 PMCID: PMC8162000 DOI: 10.1186/s12893-021-01266-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 05/23/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Osteopetrosis is a rare inherited bone disorder affected individual by osteoclast disfunction and increasing bone density. Surgery was taken for histological examination of the specimen and evidence of malignancy was not found. Finally, X-ray and gene detection lead to the diagnosis. CASE PRESENTATION We report a 10-year-old girl with two years history of pus rhinorrhea, nasal obstruction and smelly nose. She was diagnosed and treated as sinusitis. But the symptoms were recurrent. Ten months ago, she was afflicted with persistent swelling and broken skin on the right cheek. All the laboratory findings showed normal. During surgery, we resected the right gingiva, the right nasal mucosa and the right facial tissue for biopsies. Histological examination showed proliferation of granulation tissue in chronic inflammatory mucosa. X-rays showed generalized sclerosis. Genetic analysis strongly supported a novel mutation of TNFRSF11A gene which caused osteoporosis. We found a novel mutation of the c.1196C > G (p.S399X) in exon 9 of TNFRSF11A. The TNFRSF11A gene encodes RANK, which is fundamental for osteoclast formation. CONCLUSION Osteopetrosis is a rare genetic bone disease characterized by increased bone density because of bone resorption failure. Diagnosis is based on X-ray and gene analyze. Osteoclasts are bone-related cells derived from hematopoietic cell lines. Since osteoclasts arise from a hematopoietic progenitor cell of the monocytic lineage, the defect can be corrected by hematopoietic stem cell transplantation (HSCT). Better understanding of this pathological situation and pathogenesis is so important to plan appropriate immunotherapy to benefit.
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Affiliation(s)
- You Xu
- Department of Otolaryngology, Head & Neck Surgery, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610091, China
| | - Xiaoyan Yu
- Department of Otolaryngology, Head & Neck Surgery, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610091, China
| | - Mengjie Huang
- Department of Otolaryngology, Head & Neck Surgery, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610091, China.
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Alotaibi Q, Dighe M. Managing challenging pain and irritability in OSTM1 mutation-related infantile malignant osteopetrosis. BMJ Case Rep 2021; 14:14/5/e242498. [PMID: 34011644 DOI: 10.1136/bcr-2021-242498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Osteopetrosis describes a heterogeneous group of diseases characterised by increased bone density due to impaired osteoclast. The malignant infantile autosomal recessive (MIOP) form caused by mutations in OSTM1 is the most severe form of osteopetrosis. Children with this phenotype exhibit multisystemic complications, of which the neuropathic manifestations are the most severe. Infants with MIOP may present with pain and irritability that are likely to become continuous and debilitating as the disease progresses. There is limited understanding of the aetiology and management of pain in MIOP. Here, we describe a 2 month-old infant with OSTM1 mutation-related MIOP presenting with severe irritability and pain. This case provides the opportunity to discuss the cause and management of these distressing symptoms. We also review similar cases and the possible underlying mechanisms of pain and irritability to help provide a conceptual framework for the management of these symptoms in infants with OSTM1 MIOP.
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Affiliation(s)
| | - Manjiri Dighe
- Pediatrics, Al Adan Hospital, Al Ahmadi Health District, Kuwait
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Vacher J, Bruccoleri M, Pata M. Ostm1 from Mouse to Human: Insights into Osteoclast Maturation. Int J Mol Sci 2020; 21:ijms21165600. [PMID: 32764302 PMCID: PMC7460669 DOI: 10.3390/ijms21165600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 07/29/2020] [Accepted: 08/04/2020] [Indexed: 12/14/2022] Open
Abstract
The maintenance of bone mass is a dynamic process that requires a strict balance between bone formation and resorption. Bone formation is controlled by osteoblasts, while osteoclasts are responsible for resorption of the bone matrix. The opposite functions of these cell types have to be tightly regulated not only during normal bone development, but also during adult life, to maintain serum calcium homeostasis and sustain bone integrity to prevent bone fractures. Disruption of the control of bone synthesis or resorption can lead to an over accumulation of bone tissue in osteopetrosis or conversely to a net depletion of the bone mass in osteoporosis. Moreover, high levels of bone resorption with focal bone formation can cause Paget’s disease. Here, we summarize the steps toward isolation and characterization of the osteopetrosis associated trans-membrane protein 1 (Ostm1) gene and protein, essential for proper osteoclast maturation, and responsible when mutated for the most severe form of osteopetrosis in mice and humans.
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Affiliation(s)
- Jean Vacher
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, QC H2W 1R7, Canada; (M.B.); (M.P.)
- Departement de Medecine, Universite de Montreal, Montreal, QC H2W 1R7, Canada
- Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, QC H3A 1A3, Canada
- Correspondence:
| | - Michael Bruccoleri
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, QC H2W 1R7, Canada; (M.B.); (M.P.)
- Departement de Medecine, Universite de Montreal, Montreal, QC H2W 1R7, Canada
| | - Monica Pata
- Institut de Recherches Cliniques de Montreal (IRCM), Montreal, QC H2W 1R7, Canada; (M.B.); (M.P.)
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9
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Gao X, Cheng Q, Zhang X, Zhao G. Successful total hip arthroplasty for autosomal dominant osteopetrosis complicated by hip osteoarthritis: A case report and review of the literature. Exp Ther Med 2020; 19:2702-2706. [PMID: 32256752 PMCID: PMC7086189 DOI: 10.3892/etm.2020.8503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 01/16/2020] [Indexed: 11/06/2022] Open
Abstract
Osteopetrosis is a rare congenital bone disorder, characterized by systemic osteosclerosis due to a deficiency of or functional defect in osteoclasts. Autosomal dominant osteopetrosis (ADOP) is the most common form with a late onset, a stable condition, relatively few symptoms and a good prognosis. Few studies to date have reported successful total hip arthroplasty (THA) in patients with ADOP and its operative difficulties. We herein describe a case of left hip osteoarthritis in a patient with OP via THA in order to share our experience during the treatment process. The patient was a 52-years-old female with osteopetrosis who was referred to our department due to a history of left hip pain with activity limitation for 20 years. The patient reported no history of fracture or family history. The patient underwent THA in the left hip. At the 6-month, 1- and 2-year follow-up, the components were in a good position and the patient remained asymptomatic and pain-free. Therefore, THA may be a feasible treatment option when patients with ADOP suffer from painful hip osteoarthritis.
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Affiliation(s)
- Xiaoming Gao
- Department of Orthopedics, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212000, P.R. China
| | - Qian Cheng
- Department of Orthopedics, Tong Ren Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200336, P.R. China
| | - Xiaofei Zhang
- Department of Gynecology and Obstetrics, Shanghai First Maternal and Infant Healthcare Hospital Affiliated to Shanghai Tongji University, Shanghai 200040, P.R. China
| | - Guoyang Zhao
- Department of Orthopedics, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212000, P.R. China
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Chen W, Twaroski K, Eide C, Riddle MJ, Orchard PJ, Tolar J. TCIRG1 Transgenic Rescue of Osteoclast Function Using Induced Pluripotent Stem Cells Derived from Patients with Infantile Malignant Autosomal Recessive Osteopetrosis. J Bone Joint Surg Am 2019; 101:1939-1947. [PMID: 31567691 DOI: 10.2106/jbjs.19.00558] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Osteoclasts are hematopoietic stem cell-derived multinucleated cells necessary for bone remodeling and resorption. TCIRG1 encodes a protein that is an adenosine triphosphate (ATP)-dependent vacuolar proton pump required for this process. Recessive loss-of-function mutations in both copies of this gene lead to impairment of osteoclast function, with increased bone density, increased skeletal mass, and early mortality. METHODS We isolated fibroblasts from a patient with the compound heterozygous TCIRG1 mutations c.1549G>A (p.517D>N) and c.2236C>T (p.746Q>X), and reprogrammed them into iPS (induced pluripotent stem) cells. The function of osteoclasts derived from these cells was then rescued by transgenic expression of TCIRG1 cDNA. RESULTS In addition to the known effects of TCIRG1 loss of function, iPS cell-derived osteoclasts from this patient had reduced expression of the bone remodeling enzymes cathepsin K (CTSK) and tartrate-resistant acid phosphatase (TRAP), leading to reduced in vitro bone remodeling. Expression of both genes and pit formation were restored in iPS cell-derived osteoclasts following transgenic restoration of TCIRG1 expression. CONCLUSIONS Transgenic overexpression of TCIRG1 was sufficient to restore osteoclast function in iPS cell-derived osteoclasts from a patient with infantile malignant autosomal-recessive osteopetrosis. CLINICAL RELEVANCE This work provides a proof of concept for an autologous approach to treating osteopetrosis, potentially avoiding the risks associated with hematopoietic stem cell transplantation in a young patient population.
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Affiliation(s)
- Weili Chen
- Stem Cell Institute (W.C., K.T., and J.T.) and Division of Blood and Marrow Transplantation (C.E., M.J.R., P.J.O., and J.T.), Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
| | - Kirk Twaroski
- Stem Cell Institute (W.C., K.T., and J.T.) and Division of Blood and Marrow Transplantation (C.E., M.J.R., P.J.O., and J.T.), Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
| | - Cindy Eide
- Stem Cell Institute (W.C., K.T., and J.T.) and Division of Blood and Marrow Transplantation (C.E., M.J.R., P.J.O., and J.T.), Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
| | - Megan J Riddle
- Stem Cell Institute (W.C., K.T., and J.T.) and Division of Blood and Marrow Transplantation (C.E., M.J.R., P.J.O., and J.T.), Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
| | - Paul J Orchard
- Stem Cell Institute (W.C., K.T., and J.T.) and Division of Blood and Marrow Transplantation (C.E., M.J.R., P.J.O., and J.T.), Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
| | - Jakub Tolar
- Stem Cell Institute (W.C., K.T., and J.T.) and Division of Blood and Marrow Transplantation (C.E., M.J.R., P.J.O., and J.T.), Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota
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Penna S, Capo V, Palagano E, Sobacchi C, Villa A. One Disease, Many Genes: Implications for the Treatment of Osteopetroses. Front Endocrinol (Lausanne) 2019; 10:85. [PMID: 30837952 PMCID: PMC6389615 DOI: 10.3389/fendo.2019.00085] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 01/31/2019] [Indexed: 11/23/2022] Open
Abstract
Osteopetrosis is a condition characterized by increased bone mass due to defects in osteoclast function or formation. In the last decades, the molecular dissection of osteopetrosis has unveiled a plethora of molecular players responsible for different forms of the disease, some of which present also primary neurodegeneration that severely limits the therapy. Hematopoietic stem cell transplantation can cure the majority of them when performed in the first months of life, highlighting the relevance of an early molecular diagnosis. However, clinical management of these patients is constrained by the severity of the disease and lack of a bone marrow niche that may delay immune reconstitution. Based on osteopetrosis genetic heterogeneity and disease severity, personalized therapies are required for patients that are not candidate to bone marrow transplantation. This review briefly describes the genetics of osteopetrosis, its clinical heterogeneity, current therapy and innovative approaches undergoing preclinical evaluation.
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Affiliation(s)
- Sara Penna
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Hospital, Milan, Italy
- Translational and Molecular Medicine (DIMET), University of Milano-Bicocca, Monza, Italy
| | - Valentina Capo
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Hospital, Milan, Italy
| | - Eleonora Palagano
- The National Research Council (CNR) Institute for Genetic and Biomedical Research (IRGB)- CNR-IRGB, Milan Unit, Milan, Italy
- Humanitas Research Hospital, Rozzano, Italy
| | - Cristina Sobacchi
- The National Research Council (CNR) Institute for Genetic and Biomedical Research (IRGB)- CNR-IRGB, Milan Unit, Milan, Italy
- Humanitas Research Hospital, Rozzano, Italy
| | - Anna Villa
- San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), San Raffaele Hospital, Milan, Italy
- The National Research Council (CNR) Institute for Genetic and Biomedical Research (IRGB)- CNR-IRGB, Milan Unit, Milan, Italy
- *Correspondence: Anna Villa
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Jentsch TJ, Pusch M. CLC Chloride Channels and Transporters: Structure, Function, Physiology, and Disease. Physiol Rev 2018; 98:1493-1590. [DOI: 10.1152/physrev.00047.2017] [Citation(s) in RCA: 214] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
CLC anion transporters are found in all phyla and form a gene family of eight members in mammals. Two CLC proteins, each of which completely contains an ion translocation parthway, assemble to homo- or heteromeric dimers that sometimes require accessory β-subunits for function. CLC proteins come in two flavors: anion channels and anion/proton exchangers. Structures of these two CLC protein classes are surprisingly similar. Extensive structure-function analysis identified residues involved in ion permeation, anion-proton coupling and gating and led to attractive biophysical models. In mammals, ClC-1, -2, -Ka/-Kb are plasma membrane Cl−channels, whereas ClC-3 through ClC-7 are 2Cl−/H+-exchangers in endolysosomal membranes. Biological roles of CLCs were mostly studied in mammals, but also in plants and model organisms like yeast and Caenorhabditis elegans. CLC Cl−channels have roles in the control of electrical excitability, extra- and intracellular ion homeostasis, and transepithelial transport, whereas anion/proton exchangers influence vesicular ion composition and impinge on endocytosis and lysosomal function. The surprisingly diverse roles of CLCs are highlighted by human and mouse disorders elicited by mutations in their genes. These pathologies include neurodegeneration, leukodystrophy, mental retardation, deafness, blindness, myotonia, hyperaldosteronism, renal salt loss, proteinuria, kidney stones, male infertility, and osteopetrosis. In this review, emphasis is laid on biophysical structure-function analysis and on the cell biological and organismal roles of mammalian CLCs and their role in disease.
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Affiliation(s)
- Thomas J. Jentsch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany; and Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Genova, Italy
| | - Michael Pusch
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany; and Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Genova, Italy
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