Genetic susceptibility of intervertebral disc degeneration among young Finnish adults

<p>Abstract</p> <p>Background</p> <p>Disc degeneration (DD) is a common condition that progresses with aging. Although the events leading to DD are not well understood, a significant genetic influence has been found. This study was undertaken to assess the association between relevant candidate gene polymorphisms and moderate DD in a well-defined and characterized cohort of young adults. Focusing on young age can be valuable in determining genetic predisposition to DD.</p> <p>Methods</p> <p>We investigated the associations of existing candidate genes for DD among 538 young adults with a mean age of 19 belonging to the 1986 Northern Finland Birth Cohort. Nineteen single nucleotide polymorphisms (SNP) in 16 genes were genotyped. We evaluated lumbar DD using the modified Pfirrmann classification and a 1.5-T magnetic resonance scanner for imaging.</p> <p>Results</p> <p>Of the 538 individuals studied, 46% had no degeneration, while 54% had DD and 51% of these had moderate DD. The risk of DD was significantly higher in subjects with an allele G of <it>IL6 </it>SNPs rs1800795 (OR 1.45, 95% CI 1.07-1.96) and rs1800797 (OR 1.37, 95% CI 1.02-1.85) in the additive inheritance model. The role of <it>IL6 </it>was further supported by the haplotype analysis, which resulted in an association between the GGG haplotype (SNPs rs1800797, rs1800796 and rs1800795) and DD with an OR of 1.51 (95% CI 1.11-2.04). In addition, we observed an association between DD and two other polymorphisms, <it>SKT </it>rs16924573 (OR 0.27 95% CI 0.07-0.96) and <it>CILP </it>rs2073711 in women (OR 2.04, 95% CI 1.07-3.89).</p> <p>Conclusion</p> <p>Our results indicate that <it>IL6</it>, <it>SKT </it>and <it>CILP </it>are involved in the etiology of DD among young adults.</p

Proceedings of the 24th Paediatric Rheumatology European Society Congress: Part three

From Springer Nature via Jisc Publications Router.Publication status: PublishedHistory: collection 2017-09, epub 2017-09-0

Genetic risk factors for intervertebral disc degeneration

Abstract Low back pain (LBP) is the leading cause of years lived with disabilities worldwide. Intervertebral disc (IVD) degeneration is a strong contributing factor to LBP. Recent studies have shown that genetic determinants contribute markedly to IVD degeneration but knowledge about the actual genes involved as well as their roles is still limited. The aim of this thesis work was to study genetic factors that may predispose to IVD degeneration. Using both family and case-control association study designs, variants in five genes showed association with IVD degeneration on magnetic resonance imaging (MRI) in a population-based sample and among patients with sciatica due to lumbar disc herniation (LDH). We performed a candidate gene association study of the known variants implicated in IVD degeneration in a Finnish cohort of 538 young individuals with a moderate degree of lumbar IVD degeneration on MRI. We were able to confirm the associations of variants in the IL6, SKT, and CILP genes, which provides further evidence for true associations. Based on our earlier linkage study in Finnish sciatica families, we performed a candidate gene analysis and identified IL17F as a potential candidate gene. To the best of our knowledge this is the first study to observe an association between this gene and discogenic sciatica. Both IL-6 and IL-17 are pro-inflammatory cytokines with elevated expression levels in herniated tissues, which suggest a role in IVD degeneration. Study of the role of genes coding for inflammatory mediators is of interest as it may contribute to the understanding of the overall inflammatory response of the disc. In addition, we reported on the involvement of SKT in the etiology of lumbar disc herniation (LDH) both in Japanese and Finnish case-control samples. Experimental studies in mice have shown that Skt homozygous mutants exhibit disc abnormalities resulting in a kinky tale phenotype. We hypothesized that the human homolog SKT could have long-term importance in the onset of IVD degeneration by making the discs more vulnerable. Finally, through linkage studies and in the subsequent association analyses, the role of CHST3 as a novel risk factor for IVD degeneration was identified. CHST3 encodes an enzyme that catalyzes the sulfation of chondroitin, and mutations in this gene are associated with spondylepiphyseal dysplasia and humerospinal dysostosis. In our study, we identified this gene using genome –wide linkage based on data from a Southern Chinese family and speculated that mild CHST3 reduction caused by the reported susceptibility SNP could result in disc degeneration in adults in conjunction with other risk factors. This thesis provides new information about the genetic background of IVD degeneration and new insights into the etiology of the disease. The specific roles of these genes in the IVD function and pathogenesis of sciatica are not clear however, and need to be elucidated.Tiivistelmä Alaselkäkipu on yksi yleisimmistä sairauksista ja johtava syy työkyvyttömyyteen. Välilevyrappeuma myötävaikuttaa merkittävästi alaselän kipuun. Vaikka aiemmat tutkimukset ovat osoittaneet, että perintötekijöillä on vahva osuus välilevyrappeumaan, altistavat geenit ja niiden rooli tunnetaan huonosti. Tämän tutkimuksen tavoitteena oli arvioida tiettyjen perintötekijöiden osuutta välilevyrappeumassa ja tunnistaa taudille altistava geeni perheaineistossa aiemmin havaitulta kromosomialueelta. Aineistoina tutkimuksessa olivat perheaineistot sekä laajat potilas-kontrolliaineistot suomalaisesta ja aasialaisista väestöistä. Tutkimuksessa osoitimme, että perimän vaihtelut viidessä tutkitussa geenissä altistivat erilaisille välilevyrappeuman taudin muodoille. Tutkimus, jossa analysoimme aiemmin tunnistettuja alttiusgeenejä, vahvisti IL6, SKT ja CILP geenien vaihteluiden osuuden taudin alttiustekijöinä. Tutkimusaineistona oli pohjoissuomalainen syntymäkohortti, jossa välilevyrappeuma oli määritetty magneettikuvauksella (MRI). Suomalaisessa perheaineistossa tehdyn kokogenomin laajuisen kartoituksen pohjalta analysoimme IL17F geenin mahdollisena uutena alttiusgeeninä oireiselle välilevytaudille. Kahdesta geenin variantista koostuva haplotyyppi assosioitui tautiin merkitsevästi. Lisäksi osoitimme, että SKT-geenin tietty muutos altistaa välilevyn pullistumille sekä japanilaisessa että suomalaisessa potilasaineistossa. Hiirikokeissa on havainnoitu, että SKT-geenin homotsygootti mutaatio johtaa välilevy-poikkeamaan, joka edelleen aiheuttaa hiiren poikkeavan häntäilmiasun-. Hypoteesimme oli, että ihmisen SKT -geeni voi myötävaikuttaa välilevypullistuman kehittymiseen altistamalla välilevyt rappeumalle. Edelleen, laajassa usean populaation aineiston käsittävässä tutkimuksessa osoitimme CHST3-geenin muutoksen altistavan välilevyrappeumalle. Peittyvästi periytyvät muutokset tässä geenissä aiheuttavat perinnöllisiä harvinaisia luusairauksia. Tämä väitöstutkimus tarjoaa uutta tietoa välilevyrappeuman geneettisestä taustasta ja auttaa taudin syiden tutkintaa. Geenien rooli välilevyn toiminnassa ja muutosten vaikutus taudin kulkuun vaativat kuitenkin vielä lisätutkimuksia

Association of the Tag SNPs in the Human SKT Gene (KIAA1217) With Lumbar Disc Herniation

Lumbar disc herniation (LDH) is one of the most common musculo-skeletal diseases. Recent studies have indicated that LDH has strong genetic determinants, and several susceptibility genes have been reported to associate with LDH; however, its etiology and pathogenesis still remain unclear. KIAA1217 (alias SKT, the human homolog of murine Skt [Sickle tail]) is a good candidate for an LDH susceptibility gene because SKT is specifically expressed in nucleus pulposa of intervertebral discs (IVDs) in humans and mice, and SktGt mice, which are established through a large-scale gene-trap mutagenesis, exhibit progressive, postnatal onset abnormality of the IVDs. Here, we report the association of SKT with LDH. Using tag SNPs, we examined the association in two independent Japanese case-control populations and found a significant association with SKT rs16924573 in the allele frequency model (p = 0.0015). The association was replicated in a Finnish case-control population (p = 0.026). The combined p value of the two population by meta-analysis is 0.00040 (OR, 1.34; 95% CI, 1.14–1.58). Our data indicate that SKT is involved in the etiology of LDH

Multiple chronic pain states are associated with a common amino acid–changing allele in KCNS1

Not all patients with nerve injury develop neuropathic pain. The extent of nerve damage and age at the time of injury are two of the few risk factors identified to date. In addition, preclinical studies show that neuropathic pain variance is heritable. To define such factors further, we performed a large-scale gene profiling experiment which plotted global expression changes in the rat dorsal root ganglion in three peripheral neuropathic pain models. This resulted in the discovery that the potassium channel alpha subunit KCNS1, involved in neuronal excitability, is constitutively expressed in sensory neurons and markedly downregulated following nerve injury. KCNS1 was then characterized by an unbiased network analysis as a putative pain gene, a result confirmed by single nucleotide polymorphism association studies in humans. A common amino acid changing allele, the ‘valine risk allele’, was significantly associated with higher pain scores in five of six independent patient cohorts assayed (total of 1359 subjects). Risk allele prevalence is high, with 18–22% of the population homozygous, and an additional 50% heterozygous. At lower levels of nerve damage (lumbar back pain with disc herniation) association with greater pain outcome in homozygote patients is P = 0.003, increasing to P = 0.0001 for higher levels of nerve injury (limb amputation). The combined P-value for pain association in all six cohorts tested is 1.14 E−08. The risk profile of this marker is additive: two copies confer the most, one intermediate and none the least risk. Relative degrees of enhanced risk vary between cohorts, but for patients with lumbar back pain, they range between 2- and 3-fold. Although work still remains to define the potential role of this protein in the pathogenic process, here we present the KCNS1 allele rs734784 as one of the first prognostic indicators of chronic pain risk. Screening for this allele could help define those individuals prone to a transition to persistent pain, and thus requiring therapeutic strategies or lifestyle changes that minimize nerve injury

Lumbar disc degeneration is linked to a carbohydrate sulfotransferase 3 variant

Lumbar disc degeneration (LDD) is associated with both genetic and environmental factors and affects many people worldwide. A hallmark of LDD is loss of proteoglycan and water content in the nucleus pulposus of intervertebral discs. While some genetic determinants have been reported, the etiology of LDD is largely unknown. Here we report the findings from linkage and association studies on a total of 32,642 subjects consisting of 4,043 LDD cases and 28,599 control subjects. We identified carbohydrate sulfotransferase 3 (CHST3), an enzyme that catalyzes proteoglycan sulfation, as a susceptibility gene for LDD. The strongest genome-wide linkage peak encompassed CHST3 from a Southern Chinese family-based data set, while a genome-wide association was observed at rs4148941 in the gene in a meta-analysis using multiethnic population cohorts. rs4148941 lies within a potential microRNA-513a-5p (miR-513a-5p) binding site. Interaction between miR-513a-5p and mRNA transcribed from the susceptibility allele (A allele) of rs4148941 was enhanced in vitro compared with transcripts from other alleles. Additionally, expression of CHST3 mRNA was significantly reduced in the intervertebral disc cells of human subjects carrying the A allele of rs4148941. Together, our data provide new insights into the etiology of LDD, implicating an interplay between genetic risk factors and miRNA.Link_to_subscribed_fulltex