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Severity of Idiopathic Scoliosis Is Associated with Differential Methylation: An Epigenome-Wide Association Study of Monozygotic Twins with Idiopathic Scoliosis. Genes (Basel) 2021; 12:genes12081191. [PMID: 34440365 PMCID: PMC8391702 DOI: 10.3390/genes12081191] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 07/29/2021] [Accepted: 07/29/2021] [Indexed: 12/27/2022] Open
Abstract
Epigenetic mechanisms may contribute to idiopathic scoliosis (IS). We identified 8 monozygotic twin pairs with IS, 6 discordant (Cobb angle difference > 10°) and 2 concordant (Cobb angle difference ≤ 2°). Genome-wide methylation in blood was measured with the Infinium HumanMethylation EPIC Beadchip. We tested for differences in methylation and methylation variability between discordant twins and tested the association between methylation and curve severity in all twins. Differentially methylated region (DMR) analyses identified gene promoter regions. Methylation at cg12959265 (chr. 7 DPY19L1) was less variable in cases (false discovery rate (FDR) = 0.0791). We identified four probes (false discovery rate, FDR < 0.10); cg02477677 (chr. 17, RARA gene), cg12922161 (chr. 2 LOC150622 gene), cg08826461 (chr. 2), and cg16382077 (chr. 7) associated with curve severity. We identified 57 DMRs where hyper- or hypo-methylation was consistent across the region and 28 DMRs with a consistent association with curve severity. Among DMRs, 21 were correlated with bone methylation. Prioritization of regions based on methylation concordance in bone identified promoter regions for WNT10A (WNT signaling), NPY (regulator of bone and energy homeostasis), and others predicted to be relevant for bone formation/remodeling. These regions may aid in understanding the complex interplay between genetics, environment, and IS.
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Whole Exome Sequencing of 23 Multigeneration Idiopathic Scoliosis Families Reveals Enrichments in Cytoskeletal Variants, Suggests Highly Polygenic Disease. Genes (Basel) 2021; 12:genes12060922. [PMID: 34208743 PMCID: PMC8235452 DOI: 10.3390/genes12060922] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/04/2021] [Accepted: 06/10/2021] [Indexed: 12/26/2022] Open
Abstract
Adolescent idiopathic scoliosis (AIS) is a lateral spinal curvature >10° with rotation that affects 2–3% of healthy children across populations. AIS is known to have a significant genetic component, and despite a handful of risk loci identified in unrelated individuals by GWAS and next-generation sequencing methods, the underlying etiology of the condition remains largely unknown. In this study, we performed exome sequencing of affected individuals within 23 multigenerational families, with the hypothesis that the occurrence of rare, low frequency, disease-causing variants will co-occur in distantly related, affected individuals. Bioinformatic filtering of uncommon, potentially damaging variants shared by all sequenced family members revealed 1448 variants in 1160 genes across the 23 families, with 132 genes shared by two or more families. Ten genes were shared by >4 families, and no genes were shared by all. Gene enrichment analysis showed an enrichment of variants in cytoskeletal and extracellular matrix related processes. These data support a model that AIS is a highly polygenic disease, with few variant-containing genes shared between affected individuals across different family lineages. This work presents a novel resource for further exploration in familial AIS genetic research.
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Zaydman AM, Strokova EL, Pahomova NY, Gusev AF, Mikhaylovskiy MV, Shevchenko AI, Zaidman MN, Shilo AR, Subbotin VM. Etiopathogenesis of adolescent idiopathic scoliosis: Review of the literature and new epigenetic hypothesis on altered neural crest cells migration in early embryogenesis as the key event. Med Hypotheses 2021; 151:110585. [PMID: 33932710 DOI: 10.1016/j.mehy.2021.110585] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/28/2021] [Accepted: 03/24/2021] [Indexed: 12/17/2022]
Abstract
Adolescent idiopathic scoliosis (AIS) affects 2-3% of children. Numerous hypotheses on etiologic/causal factors of AIS were investigated, but all failed to identify therapeutic targets and hence failed to offer a cure. Therefore, currently there are only two options to minimize morbidity of the patients suffering AIS: bracing and spinal surgery. From the beginning of 1960th, spinal surgery, both fusion and rod placement, became the standard of management for progressive adolescent idiopathic spine deformity. However, spinal surgery is often associated with complications. These circumstances motivate AIS scientific community to continue the search for new etiologic and causal factors of AIS. While the role of the genetic factors in AIS pathogenesis was investigated intensively and universally recognized, these studies failed to nominate mutation of a particular gene or genes combination responsible for AIS development. More recently epigenetic factors were suggested to play causal role in AIS pathogenesis. Sharing this new approach, we investigated scoliotic vertebral growth plates removed during vertebral fusion (anterior surgery) for AIS correction. In recent publications we showed that cells from the convex side of human scoliotic deformities undergo normal chondrogenic/osteogenic differentiation, while cells from the concave side acquire a neuronal phenotype. Based on these facts we hypothesized that altered neural crest cell migration in early embryogenesis can be the etiological factor of AIS. In particular, we suggested that neural crest cells failed to migrate through the anterior half of somites and became deposited in sclerotome, which in turn produced chondrogenic/osteogenic-insufficient vertebral growth plates. To test this hypothesis we conducted experiments on chicken embryos with arrest neural crest cell migration by inhibiting expression of Paired-box 3 (Pax3) gene, a known enhancer and promoter of neural crest cells migration and differentiation. The results showed that chicken embryos treated with Pax3 siRNA (microinjection into the neural tube, 44 h post-fertilization) progressively developed scoliotic deformity during maturation. Therefore, this analysis suggests that although adolescent idiopathic scoliosis manifests in children around puberty, the real onset of the disease is of epigenetic nature and takes place in early embryogenesis and involves altered neural crest cells migration. If these results confirmed and further elaborated, the hypothesis may shed new light on the etiology and pathogenesis of AIS.
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Affiliation(s)
- Alla M Zaydman
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Elena L Strokova
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Nataliya Y Pahomova
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Arkady F Gusev
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Mikhail V Mikhaylovskiy
- Novosibirsk Research Institute of Traumatology and Orthopaedics named after Ya.L. Tsivyan, Novosibirsk, Russia
| | - Alexander I Shevchenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences", Novosibirsk, Russia
| | | | - Andrey R Shilo
- Novosibirsk Zoo named after R.A. Shilo, Novosibirsk, Russia
| | - Vladimir M Subbotin
- Arrowhead Pharmaceuticals Inc., Madison WI, USA; University of Pittsburgh, Pittsburgh PA, USA; University of Wisconsin, Madison WI, USA.
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Terhune EA, Cuevas MT, Monley AM, Wethey CI, Chen X, Cattell MV, Bayrak MN, Bland MR, Sutphin B, Trahan GD, Taylor MRG, Niswander LA, Jones KL, Baschal EE, Antunes L, Dobbs M, Gurnett C, Appel B, Gray R, Hadley Miller N. Mutations in KIF7 implicated in idiopathic scoliosis in humans and axial curvatures in zebrafish. Hum Mutat 2021; 42:392-407. [PMID: 33382518 DOI: 10.1002/humu.24162] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/02/2020] [Accepted: 12/11/2020] [Indexed: 12/22/2022]
Abstract
Idiopathic scoliosis (IS) is a spinal disorder affecting up to 3% of otherwise healthy children. IS has a strong familial genetic component and is believed to be genetically complex due to significant variability in phenotype and heritability. Previous studies identified putative loci and variants possibly contributing to IS susceptibility, including within extracellular matrix, cilia, and actin networks, but the genetic architecture and underlying mechanisms remain unresolved. Here, we used whole-exome sequencing from three affected individuals in a multigenerational family with IS and identified 19 uncommon variants (minor allele frequency < 0.05). Genotyping of additional family members identified a candidate heterozygous variant (H1115Q, G>C, rs142032413) within the ciliary gene KIF7, a regulator within the hedgehog (Hh) signaling pathway. Resequencing of the second cohort of unrelated IS individuals and controls identified several severe mutations in KIF7 in affected individuals only. Subsequently, we generated a mutant zebrafish model of kif7 using CRISPR-Cas9. kif7co63/co63 zebrafish displayed severe scoliosis, presenting in juveniles and progressing through adulthood. We observed no deformities in the brain, Reissner fiber, or central canal cilia in kif7co63/co63 embryos, although alterations were seen in Hh pathway gene expression. This study suggests defects in KIF7-dependent Hh signaling, which may drive pathogenesis in a subset of individuals with IS.
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Affiliation(s)
- Elizabeth A Terhune
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Melissa T Cuevas
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Anna M Monley
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,Musculoskeletal Research Center, Children's Hospital Colorado, Aurora, Colorado, USA
| | - Cambria I Wethey
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Xiaomi Chen
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Maria V Cattell
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Melisa N Bayrak
- Department of Nutritional Sciences, Dell Pediatrics Research Institute, The University of Texas at Austin, Austin, Texas, USA
| | - Morgan R Bland
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Brittan Sutphin
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - George Devon Trahan
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Matthew R G Taylor
- Department of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Lee A Niswander
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Kenneth L Jones
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Erin E Baschal
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Lilian Antunes
- Department of Orthopedics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Matthew Dobbs
- Department of Orthopedics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Christina Gurnett
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Bruce Appel
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Ryan Gray
- Department of Nutritional Sciences, Dell Pediatrics Research Institute, The University of Texas at Austin, Austin, Texas, USA
| | - Nancy Hadley Miller
- Department of Orthopedics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.,Musculoskeletal Research Center, Children's Hospital Colorado, Aurora, Colorado, USA
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Evaluation of IRX Genes and Conserved Noncoding Elements in a Region on 5p13.3 Linked to Families with Familial Idiopathic Scoliosis and Kyphosis. G3-GENES GENOMES GENETICS 2016; 6:1707-12. [PMID: 27172222 PMCID: PMC4889666 DOI: 10.1534/g3.116.029975] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Because of genetic heterogeneity present in idiopathic scoliosis, we previously defined clinical subsets (a priori) from a sample of families with idiopathic scoliosis to find genes involved with spinal curvature. Previous genome-wide linkage analysis of seven families with at least two individuals with kyphoscoliosis found linkage (P-value = 0.002) in a 3.5-Mb region on 5p13.3 containing only three known genes, IRX1, IRX2, and IRX4. In this study, the exons of IRX1, IRX2, and IRX4, the conserved noncoding elements in the region, and the exons of a nonprotein coding RNA, LOC285577, were sequenced. No functional sequence variants were identified. An intrafamilial test of association found several associated noncoding single nucleotide variants. The strongest association was with rs12517904 (P = 0.00004), located 6.5 kb downstream from IRX1. In one family, the genotypes of nine variants differed from the reference allele in all individuals with kyphoscoliosis, and two of three individuals with scoliosis, but did not differ from the reference allele in all other genotyped individuals. One of these variants, rs117273909, was located in a conserved noncoding region that functions as an enhancer in mice. To test whether the variant allele at rs117273909 had an effect on enhancer activity, zebrafish transgenesis was performed with overlapping fragments of 198 and 687 bp containing either the wild type or the variant allele. Our data suggests that this region acts as a regulatory element; however, its size and target gene(s) need to be identified to determine its role in idiopathic scoliosis.
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Abstract
STUDY DESIGN A hypothesis-driven study was conducted in a familial cohort to determine the potential association between variants within the TBX6 gene and Familial Idiopathic Scoliosis (FIS). OBJECTIVE To determine if variants within exons of the TBX6 gene segregate with the FIS phenotype within a sample of families with FIS. SUMMARY OF BACKGROUND DATA Idiopathic Scoliosis (IS) is a structural curvature of the spine whose underlying genetic etiology has not been established. IS has been reported to occur at a higher rate than expected in family members of individuals with congenital scoliosis (CS), suggesting that the two diseases might have a shared etiology. The TBX6 gene on chromosome 16p, essential to somite development, has been associated with CS in a Chinese population. Previous studies have identified linkage to this locus in families with FIS, and specifically with rs8060511, located in an intron of the TBX6 gene. METHODS Parent-offspring trios from 11 families (13 trios, 42 individuals) with FIS were selected for Sanger sequencing of the TBX6 gene. Trios were selected from a large population of families with FIS in which a genome-wide scan had resulted in linkage to 16p. RESULTS Sequencing analyses of the subset of families resulted in the identification of five coding variants. Three of the five variants were novel; the remaining two variants were previously characterized and account for 90% of the observed variants in these trios. In all cases, there was no correlation between transmission of the TBX6 variant allele and FIS phenotype. However, an analysis of regulatory markers in osteoblasts showed that rs8060511 is in a putative enhancer element. CONCLUSIONS Although this study did not identify any TBX6 coding variants that segregate with FIS, we identified a variant that is located in a potential TBX6 enhancer element. Therefore, further investigation of the region is needed.
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Lu J, Song G, Tang Q, Zou C, Han F, Zhao Z, Yong B, Yin J, Xu H, Xie X, Kang T, Lam Y, Yang H, Shen J, Wang J. IRX1 hypomethylation promotes osteosarcoma metastasis via induction of CXCL14/NF-κB signaling. J Clin Invest 2015; 125:1839-56. [PMID: 25822025 DOI: 10.1172/jci78437] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 02/19/2015] [Indexed: 12/13/2022] Open
Abstract
Osteosarcoma is a common malignant bone tumor with a propensity to metastasize to the lungs. Epigenetic abnormalities have been demonstrated to underlie osteosarcoma development; however, the epigenetic mechanisms that are involved in metastasis are not yet clear. Here, we analyzed 2 syngeneic primary human osteosarcoma cell lines that exhibit disparate metastatic potential for differences in epigenetic modifications and expression. Using methylated DNA immunoprecipitation (MeDIP) and microarray expression analysis to screen for metastasis-associated genes, we identified Iroquois homeobox 1 (IRX1). In both human osteosarcoma cell lines and clinical osteosarcoma tissues, IRX1 overexpression was strongly associated with hypomethylation of its own promoter. Furthermore, experimental modulation of IRX1 in osteosarcoma cell lines profoundly altered metastatic activity, including migration, invasion, and resistance to anoikis in vitro, and influenced lung metastasis in murine models. These prometastatic effects of IRX1 were mediated by upregulation of CXCL14/NF-κB signaling. In serum from osteosarcoma patients, the presence of IRX1 hypomethylation in circulating tumor DNA reduced lung metastasis-free survival. Together, these results identify IRX1 as a prometastatic gene, implicate IRX1 hypomethylation as a potential molecular marker for lung metastasis, and suggest that epigenetic reversion of IRX1 activation may be beneficial for controlling osteosarcoma metastasis.
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MESH Headings
- Animals
- Anoikis
- Base Sequence
- Bone Neoplasms/genetics
- Bone Neoplasms/metabolism
- Bone Neoplasms/pathology
- Cell Line, Tumor
- Cell Movement
- Chemokines, CXC/physiology
- DNA Methylation
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic/genetics
- High-Throughput Screening Assays
- Homeodomain Proteins/biosynthesis
- Homeodomain Proteins/blood
- Homeodomain Proteins/genetics
- Homeodomain Proteins/physiology
- Humans
- Lung Neoplasms/secondary
- Mice
- Mice, Inbred NOD
- Mice, SCID
- Molecular Sequence Data
- NF-kappa B/physiology
- Neoplasm Invasiveness
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/blood
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Neoplasm Transplantation
- Osteosarcoma/genetics
- Osteosarcoma/metabolism
- Osteosarcoma/secondary
- Promoter Regions, Genetic/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Neoplasm/biosynthesis
- RNA, Neoplasm/genetics
- Transcription Factors/biosynthesis
- Transcription Factors/blood
- Transcription Factors/genetics
- Transcription Factors/physiology
- Transcription, Genetic
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8
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Exome sequencing identifies a rare HSPG2 variant associated with familial idiopathic scoliosis. G3-GENES GENOMES GENETICS 2014; 5:167-74. [PMID: 25504735 PMCID: PMC4321025 DOI: 10.1534/g3.114.015669] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Idiopathic scoliosis occurs in 3% of individuals and has an unknown etiology. The objective of this study was to identify rare variants that contribute to the etiology of idiopathic scoliosis by using exome sequencing in a multigenerational family with idiopathic scoliosis. Exome sequencing was completed for three members of this multigenerational family with idiopathic scoliosis, resulting in the identification of a variant in the HSPG2 gene as a potential contributor to the phenotype. The HSPG2 gene was sequenced in a separate cohort of 100 unrelated individuals affected with idiopathic scoliosis and also was examined in an independent idiopathic scoliosis population. The exome sequencing and subsequent bioinformatics filtering resulted in 16 potentially damaging and rare coding variants. One of these variants, p.Asn786Ser, is located in the HSPG2 gene. The variant p.Asn786Ser also is overrepresented in a larger cohort of idiopathic scoliosis cases compared with a control population (P = 0.024). Furthermore, we identified additional rare HSPG2 variants that are predicted to be damaging in two independent cohorts of individuals with idiopathic scoliosis. The HSPG2 gene encodes for a ubiquitous multifunctional protein within the extracellular matrix in which loss of function mutation are known to result in a musculoskeletal phenotype in both mouse and humans. Based on these results, we conclude that rare variants in the HSPG2 gene potentially contribute to the idiopathic scoliosis phenotype in a subset of patients with idiopathic scoliosis. Further studies must be completed to confirm the effect of the HSPG2 gene on the idiopathic scoliosis phenotype.
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9
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Characterization of two ENU-induced mutations affecting mouse skeletal morphology. G3-GENES GENOMES GENETICS 2013; 3:1753-8. [PMID: 23979929 PMCID: PMC3789799 DOI: 10.1534/g3.113.007310] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Using the N-ethyl-N-nitrosourea (ENU) mutagenesis screen, we have identified two skeletal morphology mutants, Skm1 and Skm2. Positional cloning and candidate gene sequencing localized the causative point mutations within the genes coding for natriuretic peptide receptor C (NPR-C) and filamin b (FLNB), respectively. Mice that carry a mutation in Npr3 exhibit a skeletal overgrowth phenotype, resulting in an elongated body and kyphosis. Skm2 mice, carrying a mutation in Flnb, present with scoliosis and lordosis. These mutant mice will serve as useful models for the study of vertebral malformations.
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10
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Gorman KF, Julien C, Moreau A. The genetic epidemiology of idiopathic scoliosis. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2012; 21:1905-19. [PMID: 22695700 PMCID: PMC3463687 DOI: 10.1007/s00586-012-2389-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 05/17/2012] [Accepted: 05/22/2012] [Indexed: 12/23/2022]
Abstract
Purpose Idiopathic scoliosis is a complex developmental syndrome defined by an abnormal structural curvature of the spine. High treatment costs, chronic pain/discomfort, and the need for monitoring at-risk individuals contribute to the global healthcare burden of this musculoskeletal disease. Although many studies have endeavored to identify underlying genes, little progress has been made in understanding the etiopathogenesis. The objective of this comprehensive review was to summarize genetic associations/linkages with idiopathic scoliosis, as well as explore the strengths and weaknesses of each study, such that it may serve as a guide for the design and interpretation of future genetic studies in scoliosis. Methods We searched PubMed and Human Genome Epidemiology (HuGE) Navigator using the search terms “gene and scoliosis”. Linkage or association studies published in English and available full-text were further analyzed as regards results, experimental design, and statistical approach. Results We identified and analyzed 50 studies matching our criteria. These consisted of 34 candidate gene studies (6 linkage, 28 association) and 16 genome-wide studies [14 pedigree-based linkage, 2 genome-wide association studies (GWAS)]. Findings involved genes related to connective tissue structure, bone formation/metabolism, melatonin signaling pathways, puberty and growth, and axon guidance pathways. Variability in results between studies suggested ethnic and/or genetic heterogeneity. Conclusions The major difficulty in idiopathic scoliosis research is phenotypic and genetic heterogeneity. Genetic research was overrepresented by underpowered studies. The use of biological endophenotypes, as well as restricted clinical definitions, may help to partition variation and increase the power of studies to detect or confirm an effect.
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Affiliation(s)
- Kristen Fay Gorman
- Viscogliosi Laboratory in Molecular Genetics of Musculoskeletal Diseases, Sainte Justine University Hospital Research Center, Montreal, QC, Canada
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11
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Gorman KF, Christians JK, Parent J, Ahmadi R, Weigel D, Dreyer C, Breden F. A major QTL controls susceptibility to spinal curvature in the curveback guppy. BMC Genet 2011; 12:16. [PMID: 21269476 PMCID: PMC3039624 DOI: 10.1186/1471-2156-12-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 01/26/2011] [Indexed: 01/14/2023] Open
Abstract
Background Understanding the genetic basis of heritable spinal curvature would benefit medicine and aquaculture. Heritable spinal curvature among otherwise healthy children (i.e. Idiopathic Scoliosis and Scheuermann kyphosis) accounts for more than 80% of all spinal curvatures and imposes a substantial healthcare cost through bracing, hospitalizations, surgery, and chronic back pain. In aquaculture, the prevalence of heritable spinal curvature can reach as high as 80% of a stock, and thus imposes a substantial cost through production losses. The genetic basis of heritable spinal curvature is unknown and so the objective of this work is to identify quantitative trait loci (QTL) affecting heritable spinal curvature in the curveback guppy. Prior work with curveback has demonstrated phenotypic parallels to human idiopathic-type scoliosis, suggesting shared biological pathways for the deformity. Results A major effect QTL that acts in a recessive manner and accounts for curve susceptibility was detected in an initial mapping cross on LG 14. In a second cross, we confirmed this susceptibility locus and fine mapped it to a 5 cM region that explains 82.6% of the total phenotypic variance. Conclusions We identify a major QTL that controls susceptibility to curvature. This locus contains over 100 genes, including MTNR1B, a candidate gene for human idiopathic scoliosis. The identification of genes associated with heritable spinal curvature in the curveback guppy has the potential to elucidate the biological basis of spinal curvature among humans and economically important teleosts.
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Affiliation(s)
- Kristen F Gorman
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada.
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12
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Abstract
STUDY DESIGN Prospective comparative study on 100 patients with positive family history for idiopathic scoliosis. OBJECTIVE To evaluate the concordance rate for curve pattern and side in family members with idiopathic scoliosis. SUMMARY OF BACKGROUND DATA The pathogenesis of idiopathic scoliosis has been the subject of extensive research. It is termed multifactorial with a genetic component. Similar curve shape has been reported in twins with idiopathic scoliosis. METHODS We included prospectively 100 patients with idiopathic scoliosis when a relative of them was also affected with idiopathic scoliosis, and spine radiographs were available for both. Concordance for curve pattern by Lenke classification and side between family members was analyzed. RESULTS Familial concordance rate for curve pattern and side was 66% (95% confidence interval, 57-75), whereas the expected random concordance rate was 26% (95% confidence interval, 17-34). The affected relative was in 27 cases a sibling, in 32 cases a parent, in 1 case an uncle, in 2 cases a cousin, in 2 cases a half sister, in 2 cases a grandmother. Concordance rate was 65% (27/42) in siblings' pairs and 67% (32/48) in parents/child's pairs. CONCLUSION We report a high concordance rate for curve pattern and side between relatives with idiopathic scoliosis. Curve shape is likely to be genetically determined in familial scoliosis. It seems important that curve type is documented and considered in future genetic studies.
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13
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Marosy B, Justice CM, Vu C, Zorn A, Nzegwu N, Wilson AF, Miller NH. Identification of susceptibility loci for scoliosis in FIS families with triple curves. Am J Med Genet A 2010; 152A:846-55. [PMID: 20358593 DOI: 10.1002/ajmg.a.33222] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The triple curve pattern (three lateral curvatures of equal severity) has been recognized as a distinct and unique clinical subtype of scoliosis. As part of a large study of familial idiopathic scoliosis (FIS), a subset of five families with a triple curve pattern (at least one member of each family having a triple curve) was evaluated to determine if this curve pattern was linked to any of the markers previously genotyped as part of the STRP-based previous linkage screen. Model independent linkage analysis (SIBPAL, v4.5) of the initial genomic screen identified candidate regions on chromosomes 6 and 10 when FIS was analyzed both as qualitative and quantitative traits in single- and multipoint linkage analyses. Additional fine mapping analyses of this subgroup with SNPs corroborated the findings in these regions (P < 0.001). These regions have been previously linked to FIS, however, this is the first time these regions have been implicated in a clinically well-defined subgroup and may suggest a unique genetic etiology for the formation of a triple curve.
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Affiliation(s)
- Beth Marosy
- Department of Orthopaedic Surgery, Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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14
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Gruber HE, Norris RA, Kern MJ, Hoelscher GL, Ingram JA, Zinchenko N, Hanley EN. Periostin is expressed by cells of the human and sand rat intervertebral discs. Biotech Histochem 2010; 86:199-206. [DOI: 10.3109/10520291003722774] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Raggio CL, Giampietro PF, Dobrin S, Zhao C, Dorshorst D, Ghebranious N, Weber JL, Blank RD. A novel locus for adolescent idiopathic scoliosis on chromosome 12p. J Orthop Res 2009; 27:1366-72. [PMID: 19340878 PMCID: PMC4120267 DOI: 10.1002/jor.20885] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 02/25/2009] [Indexed: 02/04/2023]
Abstract
Adolescent idiopathic scoliosis (AIS) is a common disorder with strong evidence for genetic predisposition. Quantitative trait loci (QTLs) for AIS susceptibility have been identified on chromosomes. We performed a genome-wide genetic linkage scan in seven multiplex families using 400 marker loci with a mean spacing of 8.6 cM. We used Genehunter Plus to generate linkage statistics, expressed as homogeneity (HLOD) scores, under dominant and recessive genetic models. We found a significant linkage signal on chromosome 12p, whose support interval extends from near 12 pter, spanning approximately 10 million bases or 31 cM. Fine mapping within the region using 20 additional markers reveals maximum HLOD = 3.7 at 5 cM under a dominant inheritance model, and a split peak maximum HLOD = 3.2 at 8 and 18 cM under a recessive inheritance model. The linkage support interval contains 95 known genes. We found evidence suggestive of linkage on chromosomes 1, 6, 7, 8, and 14. This study is the first to find evidence of an AIS susceptibility locus on chromosome 12. Detection of AIS susceptibility QTLs on multiple chromosomes in this and other studies demonstrate that the condition is genetically heterogeneous.
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Affiliation(s)
- Cathleen L. Raggio
- Department of Pediatric Orthopedics, Hospital for Special Surgery, 535 East 70 Street, New York, NY 10021
| | - Philip F. Giampietro
- Medical Genetic Services, Marshfield Clinic, 1000 North Oak Avenue, Marshfield, WI 54449 and Department of Pediatrics, University of Wisconsin, Madison, WI 53701
| | - Seth Dobrin
- Center for Human Genetics, Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449
| | - Chengfeng Zhao
- Center for Human Genetics, Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449
| | - Donna Dorshorst
- Center for Human Genetics, Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449
| | - Nader Ghebranious
- Center for Human Genetics, Marshfield Clinic Research Foundation, 1000 North Oak Avenue, Marshfield, WI 54449
| | - James L. Weber
- Prevention Genetics, 3700 South Downwind Drive, Marshfield, WI 54449
| | - Robert D. Blank
- University of Wisconsin and the William S. Middleton Veterans Administration Medical Center, 2500 Overlook Terrace, Madison, WI 53705
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Abstract
Scoliosis is one of the oldest known deformities of humankind; however, the cause still remains ill defined. Although there is a lack of uniform agreement on the inclusion criteria for the definition of scoliosis, most investigators agree that a coronal curve must measure at least 10 degrees for the patient to be considered to have scoliosis. A broad range of articles were reviewed and the relevant publications that contributed information regarding the genetics of scoliosis were selected for inclusion in this report. Based on family pedigree and genetic studies, the proposed pattern of inheritance for markers of scoliosis are expected to be autosomal dominant, X-linked, multigene, or multifactorial. This is further complicated by locus heterogeneity, allele heterogeneity, and carrier states found in normal individuals. Although none of these modes of inheritance has been definitively proven, it appears that a multifactorial mode of inheritance with variable penetrance is the most likely method.
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Affiliation(s)
- Robert F Heary
- Department of Neurological Surgery, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103, USA.
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17
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Gorman KF, Breden F. Idiopathic-type scoliosis is not exclusive to bipedalism. Med Hypotheses 2008; 72:348-52. [PMID: 19070438 DOI: 10.1016/j.mehy.2008.09.052] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2008] [Revised: 09/12/2008] [Accepted: 09/12/2008] [Indexed: 12/11/2022]
Abstract
Human familial/idiopathic-type scoliosis (IS) is a complex genetic disorder for which the cause is unknown. The curve phenotype characteristically demonstrates pronounced morphological and developmental variability that is likely a consequence of biomechanical, environmental, and genetic differences between individuals. In addition, risk factors that affect the propensity for curves to progress to severity are unknown. Progress in understanding the fundamental biology of idiopathic-type scoliosis has been limited by the lack of a genetic/developmental animal model. Prior to consideration of teleosts, developmental idiopathic-type scoliosis has been considered to be exclusive to humans. Consequently, there is the notion that the syndrome is a result of bipedalism, and many studies try to explain the deformity from this anthrocentric viewpoint. This perspective has been reinforced by the choice of animals used for study, in that chickens and bipedal rats and mice demonstrate idiopathic-type curvature when made melatonin-deficient, but quadrupedal animals do not. Overlooked is the fact that teleosts also demonstrate similar curvature when made melatonin-deficient. Our characterization of the guppy curveback has demonstrated that non-induced idiopathic-type curvature is not exclusive to humans, nor bipedalism. We hypothesize that unique morphological, developmental and genetic parallels between the human and guppy syndromes are due to common molecular pathways involved in the etiopathogenesis of both phenotypes. We explore established gene conservation between human and teleost genomes that are in pathways hypothesized to be involved in the IS syndrome. We present non-induced vertebral wedging as a unique shared feature in IS and curveback that suggests a similar interaction between a molecular phenotype on the level of the vertebral anatomy, and biomechanics. We propose that rather than bipedalism per se, expression of idiopathic-type scoliosis is dependent on normal spinal loading applied along the cranio-caudal axis that interacts with an unknown factor causing the primary curve. In this regard, a comparative biological approach using a simplified teleost model will promote discovery of basic processes integral to idiopathic-type scoliosis in teleosts and humans, and highlight human-specific aspects of the deformity.
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Affiliation(s)
- Kristen F Gorman
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr, Burnaby, BC, Canada V5A 1S6.
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18
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Abstract
STUDY DESIGN The shape and orientation of the thoracic and lumbar zygapophyseal facets at the T1-L5 level in children were measured and analyzed. OBJECTIVE To detect the pattern of zygapophyseal facet asymmetry in the thoracic and lumbar spines in children. SUMMARY OF BACKGROUND DATA Whereas many studies have defined the pattern of zygapophyseal facet asymmetry in adults, there is insufficient data in children. METHODS A 3-dimensional digitizer was used to measure zygapophyseal facet size, topography (length, width, concavity, convexity, and lateral interfacet height), and orientation (transverse and sagittal facet angles) at the T1-L5 level. Thirty-two complete, nonpathologic skeletons of children (age range from 4 to 17 years), housed at the Hamman-Todd Human Osteological Collection (Cleveland Museum of Natural History, Cleveland, OH) were assessed. Statistical analysis included paired t tests and analysis of variance. RESULTS In general, zygapophyseal facet asymmetry in children exists only in the superior facets of the thoracic spine and is independent of age: The right superior facet is significantly shorter than the left in all thoracic vertebrae T1-T12 (up to -2.91 mm at T1), and significantly wider than the left in thoracic vertebrae T1-T9 (T8 excluded) (P < 0.003). The right superior transverse and sagittal facet angles are significantly greater than the left in thoracic vertebrae T1-T11, indicating a lesser inclination (in the sagittal plane) and more frontally positioned facet (in the transverse plane) (P < 0.003). Facet asymmetry was not evident in the superior or inferior facets of the lumbar vertebrae. CONCLUSION Facet asymmetry in thoracic vertebrae appears in early childhood. The pattern of this asymmetry differs from that reported for adults and may be considered as a possible contributing etiological factor in the development of different types of idiopathic scoliosis.
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Chinappen-Horsley U, Blake GM, Fogelman I, Kato B, Ahmadi KR, Spector TD. Quantitative trait loci for bone lengths on chromosome 5 using dual energy X-Ray absorptiometry imaging in the Twins UK cohort. PLoS One 2008; 3:e1752. [PMID: 18335030 PMCID: PMC2262137 DOI: 10.1371/journal.pone.0001752] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 01/16/2008] [Indexed: 12/21/2022] Open
Abstract
Human height is a highly heritable and complex trait but finding important genes has proven more difficult than expected. One reason might be the composite measure of height which may add heterogeneity and noise. The aim of this study was to conduct a genome-wide linkage scan to identify quantitative trait loci (QTL) for lengths of spine, femur, tibia, humerus and radius. These were investigated as alternative measures for height in a large, population–based twin sample with the potential to find genes underlying bone size and bone diseases. 3,782 normal Caucasian females, 18–80 years old, with whole body dual energy X-ray absorptiometry (DXA) images were used. A novel and reproducible method, linear pixel count (LPC) was used to measure skeletal sizes on DXA images. Intraclass correlations and heritability estimates were calculated for lengths of spine, femur, tibia, humerus and radius on monozygotic (MZ; n = 1,157) and dizygotic (DZ; n = 2,594) twins. A genome-wide linkage scan was performed on 2000 DZ twin subjects. All skeletal sites excluding spine were highly correlated. Intraclass correlations showed results for MZ twins to be significantly higher than DZ twins for all traits. Heritability results were as follows: spine, 66%; femur, 73%; tibia, 65%; humerus, 57%; radius, 68%. Results showed reliable evidence of highly suggestive linkage on chromosome 5 for spine (LOD score = 3.0) and suggestive linkage for femur (LOD score = 2.19) in the regions of 105cM and 155cM respectively. We have shown strong heritability of all skeletal sizes measured in this study and provide preliminary evidence that spine length is linked to the chromosomal region 5q15-5q23.1. Bone size phenotype appears to be more useful than traditional height measures to uncover novel genes. Replication and further fine mapping of this region is ongoing to determine potential genes influencing bone size and diseases affecting bone.
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Affiliation(s)
- Usha Chinappen-Horsley
- Twin Research and Genetic Epidemiology Unit, King's College London School of Medicine, St Thomas' Hospital, London, United Kingdom.
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Abstract
Idiopathic scoliosis in the adolescent period is a complex genetic disorder of high prevalence and extreme variability. Epidemiological approaches have confirmed the genetic basis of this disorder and have suggested multiple modes of heritability. The current challenge is to identify the genetic determinants of this condition to distinguish individuals who are at risk for severe progression. This review summarizes the literature establishing the genetic basis of this disorder. Studies focused on the identification of genes responsible for the scoliotic phenotype are reviewed, with an emphasis on recent works that have utilized contemporary strategies to isolate genes related to complex diseases. To date, molecular studies have isolated critical regions on chromosomes and X of potential importance to the etiology of scoliosis. An analysis of these works will aid in an understanding of seemingly conflicting results, and will help us determine the focus of future work.
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Affiliation(s)
- Nancy Hadley Miller
- University of Colorado at Denver and Health Sciences Center, Denver, CO, USA.
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Qiu XS, Tang NLS, Yeung HY, Qiu Y, Cheng JCY. Genetic association study of growth hormone receptor and idiopathic scoliosis. Clin Orthop Relat Res 2007; 462:53-8. [PMID: 17514010 DOI: 10.1097/blo.0b013e3180986dc2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Although the etiology of scoliosis is multifactorial, genetic factors play an important role. Recent linkage studies on familial idiopathic scoliosis revealed multiple putative predisposition loci. A genetic association study is complementary to linkage studies in defining the genetic basis of complex traits of diseases like idiopathic scoliosis. The onset and progression of adolescent idiopathic scoliosis is a manifestation of aberrant growth in the spine. Meanwhile, a high proportion of patients with adolescent idiopathic scoliosis have additional phenotypes, which suggest systemic growth dys-regulation during puberty. The growth hormone-insulin-like growth factor axis plays the principle role in skeletal growth regulation. Because growth hormone receptor alleles were associated with body stature and response to growth hormone treatment, we hypothesized the growth hormone receptor is a candidate predisposing and disease modifier gene for adolescent idiopathic scoliosis. Five hundred ten girls with adolescent idiopathic scoliosis and 363 normal subjects were recruited. Curve severity, arm span, and bone mineral densities were recorded. Five polymorphisms were studied by polymerase chain reaction-restriction fragment length polymorphism. All the genotype and allele frequencies were comparable between groups. The Cobb angles among patients of different genotypes were similar. The growth hormone receptor did not appear to be a predisposing gene or disease modifier gene of adolescent idiopathic scoliosis.
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Affiliation(s)
- Xu S Qiu
- Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong
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Gorman KF, Breden F. Teleosts as models for human vertebral stability and deformity. Comp Biochem Physiol C Toxicol Pharmacol 2007; 145:28-38. [PMID: 17240199 DOI: 10.1016/j.cbpc.2006.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 10/12/2006] [Accepted: 10/12/2006] [Indexed: 11/17/2022]
Abstract
Vertebral development is a dynamic and complicated process, and defects can be caused by a variety of influences. Spinal curvature with no known cause (idiopathic scoliosis) affects 2-3% of the human population. In order to understand the etiology and pathogenesis of complex human skeletal defects such as idiopathic scoliosis, multiple models must be used to study all of the factors affecting vertebral stability and deformity. Although fish and humans have many of the same types of offenses to vertebral integrity, they have been overlooked as a resource for study. The most common morphological deformity reported for fish are those that occur during the development of the spinal system, and as with humans, curvature is a common morphological consequence. Here we review spinal curvature in teleosts and suggest that they are an unexploited resource for understanding the basic elements of vertebral stability, deformity, development and genetics. Fish can be a value to vertebral research because they are tractable, have a diversity of non-induced vertebral deformities, and substantial genomic resources. Current animal models lack non-induced deformities and the experimental tractability necessary for genetic studies. The fact that fish are free of an appendicular skeleton should allow for analysis of basic spinal integrity without the biomechanical constraints observed in quadrupedal and bipedal models. To illustrate the point we review human idiopathic scoliosis and the potential contribution teleosts can make for the identification of causes, risk factors, and treatment options.
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Affiliation(s)
- Kristen F Gorman
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada.
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