Non-tuberculous mycobacterial infections pose a significant diagnostic and therapeutic challenge. We report two cases of such infection of the spine in HIV-negative patients who presented with deformity and neurological deficit. The histopathological features in both specimens were diagnostic of tuberculosis. The isolates were identified as Mycobacterium intracellulare and M. fortuitum by genotyping (MicroSeq 16S rDNA Full Gene assay) and as M. tuberculosis and a mycobacterium other than tuberculosis, respectively, by culture. There is a growing need for molecular diagnostic tools that can differentiate accurately between M. tuberculosis and atypical mycobacteria, especially in regions of the developing world which are experiencing an increase in non-tuberculous mycobacterial infections

Low bone mass and osteopenia have been described in the axial and peripheral skeleton of patients with adolescent idiopathic scoliosis (AIS). Recently, many studies have shown that gene polymorphism is related to osteoporosis. However, no studies have linked the association between IL6 gene polymorphism and bone mass in AIS. This study examined the association between bone mass and IL6 gene polymorphism in 198 girls with AIS. The polymorphisms of IL6-597 G→A, IL6-572 G→C and IL6-174 G→A and the bone mineral density in the lumbar spine and femoral neck were analysed and compared with their levels in healthy controls. The mean bone mineral density at both sites in patients with AIS was decreased compared with controls (p = 0.0022 and p = 0.0013, respectively). Comparison of genotype frequencies between AIS and healthy controls revealed a statistically significant difference in IL6-572 G→C polymorphism (p = 0.0305). There was a significant association between the IL6-572 G→C polymorphism and bone mineral density in the lumbar spine, with the CC genotype significantly higher with the GC (p = 0.0124) or GG (p = 0.0066) genotypes. These results suggest that the IL6-572 G→C polymorphism is associated with bone mineral density in the lumbar spine in Korean girls with AIS

Introduction. Kyphoscoliosis is defined by a structural lateral curvature of the spine of 10° or more and an excessive thoracic kyphotic curve of 40° or more. Genetic analyses of families in which two or more members had kyphoscoliosis identified a 3·5 Mb area on chromosome 5p containing three genes of the Iroquois (IRX) homeobox family, IRX1, IRX2, and IRX4, which were then sequenced. Methods. Exons and highly conserved non-coding regions (HNCRs) 500 kb upstream and downstream fromIRX1, IRX2, and IRX4 were sequenced in 46 individuals from six families. Selection of these elements was based on PhastCons Placental Mammal Conserved Elements, Multiz Alignment. Single-nucleotide polymorphism (SNP) genotypes and sequence variants were obtained from all individuals. There were 431 SNPs, 61 in IRX4 regions, 80 in IRX2 regions, and 290 in IRX1 regions. 137 SNPs were novel. Mendelian inconsistencies were detected with PEDCHECK (inconsistency rate: 1·4%; missing data: 2·8%). SNPs and individuals with greater than 10% missing rate were excluded. Association analyses (ASSOC [SAGE version 6.0.1]) of the quantitative trait with patient's largest curve, were undertaken on 391 SNPs. Results. Association analyses resulted in 12 SNPs with p values less than 0·025, 11 of which were located upstream and downstream from IRX1. The most significant p value (p=0·000382) was obtained for rs35710183 (table). Multiple variants were found surrounding IRX1. The most prominent is a single base-pair deletion in all affected individuals genotyped in one family. All individuals with kyphoscoliosis and those with scoliotic curves greater than 35° had genotypes differing from the reference (unaffected) genotype for 23 SNPs. Several of these SNPs had significant p values for the association analyses done previously. Conclusions. The phenotype of kyphoscoliosis has been linked to sequence variants that lie within regulatory regions of the IRX homeobox gene family. Further analyses to establish the relevance of these findings will be done through in-vivo and in-vitro assays. The identification of spinal genetic determinants related to axial growth and maturation will help with the understanding of spinal pathology and potentially allow for development of directed therapeutic interventions

Aims

Degenerative cervical spondylosis (DCS) is a common musculoskeletal disease that encompasses a wide range of progressive degenerative changes and affects all components of the cervical spine. DCS imposes very large social and economic burdens. However, its genetic basis remains elusive.

Purpose. Back pain is the primary cause of disability worldwide yet surprisingly little is known of the underlying pathobiology. We conducted a genome-wide association study (GWAS) meta-analysis of chronic back pain (CBP). Adults of European ancestry from 15 cohorts in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and UK Biobank were studied. Methods. CBP cases were defined as reporting back pain present for ≥3–6 months; non-cases were included as comparisons (“controls”). Each cohort conducted genotyping followed by imputation. GWAS used logistic regression with additive genetic effects adjusting for age, sex, study-specific covariates, and population substructure. Suggestive (p<5×10. –7. ) & genome-wide significant (p<5×10. –8. ) variants were carried forward for replication in an independent sample of UK Biobank participants. Discovery sample n = 158,025 individuals, including 29,531 CBP cases. Results. Genome-wide significant association was found for intron variant rs12310519 in SOX5 (OR=1.08, p=7.2×10. −10. ). This was replicated in the independent sample n = 283,752, comprising 50,915 cases (OR 1.06, p=5.3×10. −11. ); in joint meta-analysis OR=1.07, p=4.5×10. −19. exceeding genome-wide significance. We found three other suggestive associations in discovery, two of which exceeded genome-wide significance in joint meta-analysis: an intergenic variant rs7833174 located between CCDC26 and GSDMC (OR 1.05, p=4.4×10. −13. ), and an intron variant, rs4384683, in DCC (OR 0.97, p=2.4×10. −10. ). Conclusion. We have identified and replicated a genetic locus associated with CBP (SOX5). We also identified 2 other loci that reached genome-wide significance in a 2-stage joint meta-analysis (CCDC26/GSDMC and DCC) which will shed light on the pathogenic mechanisms underlying CBP. Conflicts of interest: YA and LK are owners of Maatschap PolyOmica. This study was supported by the European Community's Seventh Framework Programme funded project PainOmics (Grant agreement n. 602736) and conducted using the UK Biobank Resource (project # 18219). CHARGE and other cohort-specific funding sources to be submitted- see below

It has been suggested that matrix metalloproteinase-3 (MMP-3, stromelysin-1) has an important role in the degeneration of intervertebral discs (IVDs). A human MMP-3 promoter 5A/6A polymorphism was reported to be involved in the regulation of MMP-3 gene expression. We suggest that IVD degeneration is associated with 5A/6A polymorphism. We studied 54 young and 49 elderly Japanese subjects. Degeneration of the lumbar discs was graded using MRI in the younger group and by radiography in the elderly. 5A/6A polymorphism was determined by polymerase-chain reaction-based assays. We found that the 5A5A and 5A6A genotype in the elderly was associated with a significantly larger number of degenerative IVDs than the 6A6A (p < 0.05), but there was no significant difference in the young. In the elderly, the IVD degenerative scores were also distributed more highly in the 5A5A and 5A6A genotypes (p = 0.0029). Our findings indicate that the 5A allele is a possible risk factor for the acceleration of degenerative changes in the lumbar disc in the elderly

Introduction. Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity. It occurs mainly in girls and progresses during pre-pubertal and pubertal growth, which is a crucial period for bone mass acquisition. The cause and molecular mechanisms of AIS are not clear; at present the consensus is that AIS has a multifactor cause, with many genetic factors. During the past 5 years, considerable effort has been devoted to identify a gene or genes that cause a predisposition to AIS. Many loci for this disorder have been mapped to different chromosome regions, but no genes have been clearly identified as being responsible for AIS, and, most importantly, the resulting protein defects remain to be shown. We aimed to identify the gene(s) that could be involved in AIS and to validate their involvement by both genetic and functional analyses. Methods. A large multiplex AIS French family was chosen for this study on the basis of clinical and radiological data. Whole genome genotyping of the 20 members of this family led to the mapping of a dominant disease-causing gene to two critical genomic intervals (Edery and colleagues, Eur J Hum Genet, accepted [2011]), but the causative mutation remains to be identified. In parallel, gene expression profiling was investigated by microarray analysis in RNA samples isolated from osteoblasts derived from healthy individuals and those with AIS. RNA samples were extracted from osteoblasts, purified, fluorescently labelled, and then hybridised to gene expression microarrays with the Illumina expression BeadChips technology containing more than 46 000 probes for the human genome (HumanHT-12). Data analysis in R version 2.10.1 (Bioconductor packages oligo and limma) was done, and genes that had at least 1·5-fold change in expression were considered differentially regulated relative to controls. AIS candidate genes within the critical intervals were selected on the basis of their mRNA expression in AIS individuals and by their known functions. The coding regions of these candidate genes were then sequenced to identify potential mutations. The biological activity of mutant proteins is under evaluation by in-vivo functional studies in zebrafish. Results. In the AIS family, a maximum LOD score of 3·01 was reached on two specific chromosomal regions. The interval lengths of these regions were 7cM and 12cM. These two regions contain several genes that might be responsible for AIS. Microarray analysis showed many genes that are differentially regulated in AIS osteoblasts compared with control osteoblasts. We recorded that 2·6% of the 24000 genes examined were upregulated in AIS osteoblasts, whereas 2·16% of them were downregulated. We observed a roughly 3-fold increase or decrease in the transcripts of many genes in AIS osteoblasts. Some of the differentially regulated genes are located within the two chromosomal candidate regions. The sequencing of the candidate genes' coding sequences was done on the family members. Sequence analysis showed two rare SNPs located on the coding regions of a gene that we called CH5G1. These two SNPs are located on the C-terminal region of the CH5G1 protein and affect its structure and probably its cellular activity and biological process leading to the disease. The C-terminal region of this protein interacts with the mRNA of a gene whose defects cause scoliosis as a secondary phenotype. The pathogenic nature of these SNPs is being investigated in the zebrafish model. The results suggest that CH5G1 gene's defects could be associated with AIS in this family. Conclusions. Identification of susceptibility genes for AIS will facilitate the understanding of underlying biochemical pathways (functional studies) and ultimately the development of specific therapies (pharmacological studies). This is likely to have important implications, since the cause of AIS is unknown. Acknowledgments. This study is supported by the Fondation Yves Cotrel, Institut de France

The lack of an accurate, rapid diagnostic test for mycobacterium tuberculosis (TB) is a major handicap in the management of spinal TB. GeneXpert, a new, rapid molecular diagnostic test is recommended as the first line investigation for suspected pulmonary TB in areas with a high prevalence of HIV or drug resistance, yet it has not been validated for the diagnosis of musculoskeletal TB.

The aim of this study was to assess the accuracy of GeneXpert in diagnosing spinal TB.

A prospective clinical study of 69 consecutive adults with suspected spinal TB was conducted at a tertiary hospital in an area with the highest incidence and prevalence of TB in the world. GeneXpert was used on tissue samples of the enrolled patients and its diagnostic accuracy compared with a reference standard of tissue in liquid culture. A total of 71 spine samples from 69 patients (two re-biopsies) were included in the study.

The GeneXpert test showed a sensitivity of 95.6% and specificity of 96.2% for spinal TB. The results of the GeneXpert test were available within 48 hours compared with a median of 35 days (IQR 15 to 43) for cultures. All cases of multi-drug resistant TB (MDR TB) were diagnosed accurately with the GeneXpert test. The MDR TB rate was 5.8%.

Cite this article: Bone Joint J 2014;96-B:1366–9.

Aims

Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed non-operatively or operatively in our institution.