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The Induced Pluripotent Stem Cells in Articular Cartilage Regeneration and Disease Modelling: Are We Ready for Their Clinical Use? Cells 2022; 11:cells11030529. [PMID: 35159338 PMCID: PMC8834349 DOI: 10.3390/cells11030529] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/29/2022] [Accepted: 02/01/2022] [Indexed: 02/01/2023] Open
Abstract
The development of induced pluripotent stem cells has brought unlimited possibilities to the field of regenerative medicine. This could be ideal for treating osteoarthritis and other skeletal diseases, because the current procedures tend to be short-term solutions. The usage of induced pluripotent stem cells in the cell-based regeneration of cartilage damages could replace or improve on the current techniques. The patient’s specific non-invasive collection of tissue for reprogramming purposes could also create a platform for drug screening and disease modelling for an overview of distinct skeletal abnormalities. In this review, we seek to summarise the latest achievements in the chondrogenic differentiation of pluripotent stem cells for regenerative purposes and disease modelling.
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Tchio Tchoumba MA, Bai Y, Jin R, Yu X, Male M. Metatropic Dysplasia of Nonlethal Variant in a Chinese Child - A Case Report. Orthop Surg 2019; 12:333-336. [PMID: 31808622 PMCID: PMC7031589 DOI: 10.1111/os.12546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/01/2019] [Accepted: 09/01/2019] [Indexed: 12/04/2022] Open
Abstract
Metatropic dysplasia (MD), is a rare skeletal dysplasia occurring predominantly in infants characterized by a distinctive long torso and short limbs; it is as a result of mutations in the TRPV4 gene. However, a clear distinction between various forms of skeletal dysplasias caused by the transient receptor potential vanilloid 4 (TRPV4) gene is difficult but could be achieved by a combination of gene sequencing, medical and radiological criteria. We hereby report a case of a 14‐month old girl who presented with an abnormal stature. The diagnosis of nonlethal MD was confirmed by X‐ray with dumbbell‐shaped long bones, platyspondyly, and delayed carpal ossification, as well as broadened pelvis with marginally widened ilia, epiphyseal plates, and slightly flattened acetabula. Furthermore, gene sequencing confirmed gene mutation on exon 15 of the TRPV4 gene with a heterozygous missense mutation (c.2396C > T), but no mutation was present in her parents. Our findings recorded metatropic dysplasia with the c.2396C > T mutation in the TRPV4 gene in China. This mutation caused changes in amino acid of TRPV4, which can induce growth retardation in children.
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Affiliation(s)
- Michele A Tchio Tchoumba
- Pediatric Department, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Bai
- Pediatric Department, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Runming Jin
- Pediatric Department, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xianying Yu
- Pediatric Department, Zhumadian City, The First People's Hospital, Zhumadian, China
| | - Musa Male
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Bauer JM, Ditro CP, Mackenzie WG. The Management of Kyphosis in Metatropic Dysplasia. Spine Deform 2019; 7:494-500. [PMID: 31053321 DOI: 10.1016/j.jspd.2018.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 09/08/2018] [Accepted: 09/09/2018] [Indexed: 11/17/2022]
Abstract
DESIGN Retrospective review. OBJECTIVE To describe the presentation and progression, and compare treatments of severe thoracic kyphosis in a cohort of patients with metatropic dysplasia. SUMMARY OF BACKGROUND DATA Metatropic dysplasia is a rare skeletal dysplasia characterized by several abnormalities, including severe platyspondyly and vertebral wedging. These lead to marked kyphoscoliosis that begins in the first year of life and progresses to a stiff, short thorax and restrictive lung disease. There is no study that specifically addresses treatment of kyphosis in this cohort. METHODS A 12-year retrospective chart review at a single institution was performed to identify metatropic dysplasia patients. Comparison between four main treatment groups-observation, bracing, anterior release and growing construct, and anterior release and final fusion-were made radiographically with regard to thoracolumbar, T2-T12, and major Cobb kyphosis; sagittal vertical alignment; and C7-kyphosis apex distance, taken at presentation, pre- and posttreatment, and final follow-up. RESULTS Twenty patients with metatropic dysplasia presented at an average age of 3.1 years with a kyphosis of 75°, and were followed an average of 8.5 years. Those treated surgically presented with an average of 86.7° kyphosis, 88 mm C7-kyphosis apex distance, and 50 mm positive sagittal vertical alignment (SVA). Postsurgical reduction of kyphosis averaged 43° with less than 4° loss of correction in all groups except the constructs involving rib fixation. Recent use of staged thoracoscopic anterior soft tissue release, halo traction, and growing rod construct has produced the most dramatic results with average kyphosis correction of 71° and evidence of anterior bony remodeling. In those treated with observation, kyphosis progressed less than a quarter degree per year. CONCLUSIONS Thoracic kyphosis in metatropic dysplasia does not uniformly progress in all patients and therefore can be initially observed. In those who progress, several surgical options exist including growth-friendly constructs that have demonstrated success without a higher rate of complications. LEVEL OF EVIDENCE Level IV.
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Affiliation(s)
- Jennifer M Bauer
- Seattle Children's Hospital, 4800 Sand Point Way NE, Seattle, WA 98105, USA; Department of Orthopedics and Sports Medicine, University of Washington, 1959 N.E. Pacific St., Box 356500, Seattle, WA 98195-6500, USA.
| | - Colleen P Ditro
- Nemours/Alfred I. duPont Hospital for Children, 1600 Rockland Rd, Wilmington, DE 19803, USA
| | - William G Mackenzie
- Nemours/Alfred I. duPont Hospital for Children, 1600 Rockland Rd, Wilmington, DE 19803, USA
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Characteristic Diagnostic Clues of Metatropic Dysplasia: The Lumbothoracic Humpback with Dumbbell Appearance of the Long Bones. Balkan J Med Genet 2018; 21:35-38. [PMID: 30984522 PMCID: PMC6454243 DOI: 10.2478/bjmg-2018-0025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Metatropic dysplasia (MD) is a rare skeletal dysplasia associated with heterozygous mutations in the TRPV4 gene. We describe a 28-month-old boy with knock-knees referred for metabolic investigation suspected of carrying vitamin D-resistant rickets. He has received regular vitamin D prophylaxis at the usual dose. Laboratory investigations revealed normal values for calcium, phosphorus and alkaline phosphatase. He was short (-3.5 SDS), his mental development was normal, and he started to walk at the age of 22 months. The diagnostic clue for the diagnosis of metatropic dysplasia was the presence of the hump back in the upper lumbar and lower thoracic vertebrae, in addition to a long and narrow chest. An X-ray survey of the skeleton revealed platyspondyly, dysplastic metaphyses with dumbbell appearance of the long bones, kyphoscoliosis, and narrow and elongated thorax with short ribs. This is the first patient with MD in the Republic of Macedonia. Knock-knees were the cause of his referral, as a peculiarity of his phenotype. The very presence of the hump back, and the dumbbell appearance of the long bones distinguished the MD from other bone dysplasias with similar characteristics. We believe that the presence of those two features can shorten the path to accurate diagnosis in the crowded field of overlapping skeletal dysplasias. The diagnosis of MD in this patient was further confirmed by the discovery of the mutation c.2396C>T; p.Pro799Leu (P799L) of the TRPV4 gene.
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Metatropic dysplasia in third trimester of pregnancy and a novel causative variant in the TRPV4 gene. Eur J Med Genet 2017; 60:365-368. [DOI: 10.1016/j.ejmg.2017.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 04/06/2017] [Accepted: 04/10/2017] [Indexed: 12/22/2022]
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Theroux MC, Lopez M, Olszewsky PJ, DiCindio S, Arai L, Ditro C, Bober MB, Olla OO, Uejima T, West DW, Mackenzie WG. Metatropic dysplasia-a skeletal dysplasia with challenging airway and other anesthetic concerns. Paediatr Anaesth 2017; 27:596-603. [PMID: 28321993 DOI: 10.1111/pan.13101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/18/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Metatropic dysplasia is a rare form of skeletal dysplasia requiring multiple anesthetics for surgical and imaging procedures, most of which are orthopedic procedures. We provide centralized care to patients with skeletal dysplasia at our tertiary care pediatric hospital, and we were able to collect the largest number of metatropic dysplasia patients reported to date. AIM The aim of this retrospective study was to describe and characterize the anesthetic difficulties in this high-risk population. METHODS Medical charts of all patients with metatropic dysplasia were reviewed to collect data, including anesthetics performed, difficulties, and complications related to the anesthetic care, co-morbid conditions, and related events. RESULTS Twenty-three patients with metatropic dysplasia underwent 188 anesthetics with 61% of the anesthetics having been administered for orthopedic procedures. Fourteen of 23 (60.8%) progressively became difficult to intubate over the course of their care, with 12 out of 14 having undergone cervical spine fusion. These 14 patients had a total of 133 procedures. Sixty procedures (45.1%) had an airway described as difficult. Glidescope was the difficult airway tool most commonly used (68%) with flexible fiberoptic scope used 12% and Miller or Macintosh blade used 18% of the time. In addition to the airway difficulties, spinal canal narrowing or stenosis was widely prevalent, and no neuraxial anesthetic was performed in any of our patients. CONCLUSION Difficult airway is the most common co-morbid condition present in patients with metatropic dysplasia, especially if their cervical spine has been fused. Familiarity with the difficulties involving the airway and its management is critical in safe and successful management of anesthesia in this high-risk population.
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Affiliation(s)
- Mary C Theroux
- Department of Anesthesiology and Perioperative Medicine, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Pediatrics, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Martha Lopez
- Nemours Biomedical Research, Wilmington, DE, USA
| | - Patricia J Olszewsky
- Department of Nursing, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Sabina DiCindio
- Department of Anesthesiology and Perioperative Medicine, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Lynda Arai
- Department of Anesthesiology and Perioperative Medicine, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Colleen Ditro
- Department of Orthopedic Surgery, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Michael B Bober
- Department of Genetics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Olubukola Opeyemi Olla
- Department of Anesthesiology and Perioperative Medicine, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Tetsu Uejima
- Department of Anesthesiology and Perioperative Medicine, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA.,Department of Anesthesiology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Department of Pediatrics, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - David W West
- Department of Pediatrics, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA.,Nemours Health Informatics, Wilmington, DE, USA
| | - William G Mackenzie
- Department of Nursing, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
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Garel C, Dhouib A, Sileo C, Cormier-Daire V, Ducou le Pointe H. Prenatal diagnosis of metatropic dysplasia: beware of the pseudo-bowing sign. Pediatr Radiol 2014; 44:344-8. [PMID: 24121766 DOI: 10.1007/s00247-013-2806-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 05/29/2013] [Accepted: 09/15/2013] [Indexed: 10/26/2022]
Abstract
Metatropic dysplasia is a very rare form of osteochondrodysplasia with only one case of prenatal diagnosis described in the literature. It is characterized by marked shortening of the long bones with severe platyspondyly and dumbbell-shape metaphyses. We report a case of metatropic dysplasia that was diagnosed prenatally and describe the findings on US and CT. The pregnancy was terminated and the post-mortem radiographs are shown. The woman had been referred for short and bowed long bones. Severe metaphyseal enlargement was a misleading finding because it had been misinterpreted as limb bowing. Thus when abnormal curvature of the long bones is observed at prenatal US, attention should be drawn not only to the diaphyses but also to the metaphyses because severe metaphyseal enlargement might be responsible for pseudo-bowing.
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Song HR, Sinha S, Song SH, Suh SW. A case of metatropic dysplasia: operative treatment of severe kyphoscoliosis and limb deformities. Oman Med J 2013; 28:445-7. [PMID: 24223250 DOI: 10.5001/omj.2013.123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/04/2013] [Indexed: 11/03/2022] Open
Abstract
Metatropic dysplasia is a rare but severe spondyloepimetaphyseal dysplasia characterized by long trunk and short extremities. The exact incidence is not known; however, 81 cases have been reported in the literature till now. Due to progressive kyphoscoliosis, there is a reversal of proportions in childhood (shortening of trunk with relative long extremities). The diagnostic radiographic findings include marked platyspondyly (wafer-thin vertebral bodies), widened metaphyses (dumbbell-shaped tubular bones) and small epiphysis and a specific pelvic shape. The severe kyphoscoliosis is relentless and resistant to conservative treatment with bracing. Operative treatment is controversial due to the recurrence of deformity despite aggressive correction. We, herein report a case of this rare dysplasia and its follow-up after corrective surgery for spine and limb deformity. The excellent correction and good functional pulmonary status at 6-year follow-up has never been previously reported.
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Affiliation(s)
- Hae Ryong Song
- Institute of Rare Diseases and Department of Orthopaedic Surgery, Korea University Medical Centre, Guro Hospital, #80 Guro-dong, Guro-gu, Seoul 152703, Korea
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Nishimura G, Lausch E, Savarirayan R, Shiba M, Spranger J, Zabel B, Ikegawa S, Superti-Furga A, Unger S. TRPV4-associated skeletal dysplasias. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2012; 160C:190-204. [PMID: 22791502 DOI: 10.1002/ajmg.c.31335] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dominant mutations in the TRPV4 gene result in a bone dysplasia family and form a continuous phenotypic spectrum that includes, in decreasing severity, lethal, and nonlethal metatropic dysplasia (MD), spondylometaphyseal dysplasia Kozlowski type (SMDK), and autosomal dominant brachyolmia. Several rare variant phenotypes that have some overlap but deviate in some ways from the general pattern have also been described. The known variant phenotypes are spondyloepiphyseal dysplasia Maroteaux type (Pseudo-Morquio type 2), parastremmatic dysplasia, and familial digital arthropathy with brachydactyly. Interestingly, different TRPV4 mutations have been associated with dominantly inherited neurologic disorders such as congenital spinal muscular atrophy and hereditary motor and sensory neuropathy. Finally, a small number of patients have been identified in whom a TRPV4 mutation results in a phenotype combining skeletal dysplasia with peripheral neuropathy. The TRPV4 gene encodes a regulated calcium channel implicated in multiple and diverse cellular processes. Over 50 different TRPV4 mutations have been reported, with two codons appearing to be mutational hot spots: P799 in exon 15, mostly associated with MD, and R594 in exon 11, associated with SMDK. While most pathogenic mutations tested so far result in activation of the calcium channel in vitro, the mechanisms through which TRPV4 activation results in skeletal dysplasia and/or peripheral neuropathy remain unclear and the genotype-phenotype correlations in this group of disorders remains somewhat mysterious. Since the phenotypic expression of most mutations seems to be relatively constant, careful clinical and radiographic assessment is useful in directing molecular analysis.
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Affiliation(s)
- Gen Nishimura
- Génétique Médicale, CHUV, Av. Decker 2, 1011 Lausanne, Switzerland
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Nemec SF, Cohn DH, Krakow D, Funari VA, Rimoin DL, Lachman RS. The importance of conventional radiography in the mutational analysis of skeletal dysplasias (the TRPV4 mutational family). Pediatr Radiol 2012; 42:15-23. [PMID: 21863289 DOI: 10.1007/s00247-011-2229-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Revised: 07/12/2011] [Accepted: 07/26/2011] [Indexed: 12/25/2022]
Abstract
The spondylo and spondylometaphyseal dysplasias (SMDs) are characterized by vertebral changes and metaphyseal abnormalities of the tubular bones, which produce a phenotypic spectrum of disorders from the mild autosomal-dominant brachyolmia to SMD Kozlowski to autosomal-dominant metatropic dysplasia. Investigations have recently drawn on the similar radiographic features of those conditions to define a new family of skeletal dysplasias caused by mutations in the transient receptor potential cation channel vanilloid 4 (TRPV4). This review demonstrates the significance of radiography in the discovery of a new bone dysplasia family due to mutations in a single gene.
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Affiliation(s)
- Stefan F Nemec
- International Skeletal Dysplasia Registry, Medical Genetics Institute, Cedars Sinai Medical Center, 8700 Beverly Boulevard, PACT Suite 400, Los Angeles, CA 90048, USA.
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Loukin S, Su Z, Kung C. Increased basal activity is a key determinant in the severity of human skeletal dysplasia caused by TRPV4 mutations. PLoS One 2011; 6:e19533. [PMID: 21573172 PMCID: PMC3088684 DOI: 10.1371/journal.pone.0019533] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 04/04/2011] [Indexed: 02/01/2023] Open
Abstract
TRPV4 is a mechanically activated Ca2+-passing channel implicated in the sensing of forces, including those acting on bones. To date, 33 mutations are known to affect human bone development to different extents. The spectrum of these skeletal dysplasias (SD) ranges from dominantly inherited mild brachylomia (BO) to neonatal lethal forms of metatropic dysplasia (MD). Complexities of the results from fluorescence and electrophysiological studies have led to questions on whether channel activity is a good predictor of disease severity. Here we report on a systematic examination of 14 TRPV4 mutant alleles covering the entire SD spectrum. Expressed in Xenopus oocyte and without any stimulation, the wild-type channel had a ∼1% open probability (Po) while those of most of the lethal MD channels approached 100%. All mutant channels had higher basal open probabilities, which limited their further increase by agonist or hypotonicity. The magnitude of this limitation revealed a clear correlation between the degree of over-activity (the molecular phenotype) and the severity of the disease over the entire spectrum (the biological phenotype). Thus, while other factors are at play, our results are consistent with the increased TRPV4 basal activity being a critical determinant of the severity of skeletal dysplasia. We discuss how the channel over-activity may lead to the “gain-of-function” phenotype and speculate that the function of wild-type TRPV4 may be secondary in normal bone development but crucial in an acute process such as fracture repair in the adult.
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Affiliation(s)
- Stephen Loukin
- Laboratory of Molecular Biology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- * E-mail:
| | - Zhenwei Su
- Laboratory of Molecular Biology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
| | - Ching Kung
- Laboratory of Molecular Biology, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
- Department of Genetics, University of Wisconsin–Madison, Madison, Wisconsin, United States of America
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Transient Receptor Potential Genes and Human Inherited Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 704:1011-32. [DOI: 10.1007/978-94-007-0265-3_52] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Camacho N, Krakow D, Johnykutty S, Katzman PJ, Pepkowitz S, Vriens J, Nilius B, Boyce BF, Cohn DH. Dominant TRPV4 mutations in nonlethal and lethal metatropic dysplasia. Am J Med Genet A 2010; 152A:1169-77. [PMID: 20425821 DOI: 10.1002/ajmg.a.33392] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Metatropic dysplasia is a clinical heterogeneous skeletal dysplasia characterized by short extremities, a short trunk with progressive kyphoscoliosis, and craniofacial abnormalities that include a prominent forehead, midface hypoplasia, and a squared-off jaw. Dominant mutations in the gene encoding TRPV4, a calcium permeable ion channel, were identified all 10 of a series of metatropic dysplasia cases, ranging in severity from mild to perinatal lethal. These data demonstrate that the lethal form of the disorder is dominantly inherited and suggest locus homogeneity in the disease. Electrophysiological studies demonstrated that the mutations activate the channel, indicating that the mechanism of disease may result from increased calcium in chondrocytes. Histological studies in two cases of lethal metatropic dysplasia revealed markedly disrupted endochondral ossification, with reduced numbers of hypertrophic chondrocytes and presence of islands of cartilage within the zone of primary mineralization. These data suggest that altered chondrocyte differentiation in the growth plate leads to the clinical findings in metatropic dysplasia.
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Affiliation(s)
- Natalia Camacho
- Department of Orthopedic Surgery, University of California at Los Angeles, Los Angeles, CA 90048, USA
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14
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Krakow D, Vriens J, Camacho N, Luong P, Deixler H, Funari TL, Bacino CA, Irons MB, Holm IA, Sadler L, Okenfuss EB, Janssens A, Voets T, Rimoin DL, Lachman RS, Nilius B, Cohn DH. Mutations in the gene encoding the calcium-permeable ion channel TRPV4 produce spondylometaphyseal dysplasia, Kozlowski type and metatropic dysplasia. Am J Hum Genet 2009; 84:307-15. [PMID: 19232556 DOI: 10.1016/j.ajhg.2009.01.021] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Revised: 01/22/2009] [Accepted: 01/26/2009] [Indexed: 11/28/2022] Open
Abstract
The spondylometaphyseal dysplasias (SMDs) are a group of short-stature disorders distinguished by abnormalities in the vertebrae and the metaphyses of the tubular bones. SMD Kozlowski type (SMDK) is a well-defined autosomal-dominant SMD characterized by significant scoliosis and mild metaphyseal abnormalities in the pelvis. The vertebrae exhibit platyspondyly and overfaced pedicles similar to autosomal-dominant brachyolmia, which can result from heterozygosity for activating mutations in the gene encoding TRPV4, a calcium-permeable ion channel. Mutation analysis in six out of six patients with SMDK demonstrated heterozygosity for missense mutations in TRPV4, and one mutation, predicting a R594H substitution, was recurrent in four patients. Similar to autosomal-dominant brachyolmia, the mutations altered basal calcium channel activity in vitro. Metatropic dysplasia is another SMD that has been proposed to have both clinical and genetic heterogeneity. Patients with the nonlethal form of metatropic dysplasia present with a progressive scoliosis, widespread metaphyseal involvement of the appendicular skeleton, and carpal ossification delay. Because of some similar radiographic features between SMDK and metatropic dysplasia, TRPV4 was tested as a disease gene for nonlethal metatropic dysplasia. In two sporadic cases, heterozygosity for de novo missense mutations in TRPV4 was found. The findings demonstrate that mutations in TRPV4 produce a phenotypic spectrum of skeletal dysplasias from the mild autosomal-dominant brachyolmia to SMDK to autosomal-dominant metatropic dysplasia, suggesting that these disorders should be grouped into a new bone dysplasia family.
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Affiliation(s)
- Deborah Krakow
- Department of Orthopedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, CA 90024, USA
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