Genetic susceptibility of lumbar degenerative disc disease in young adults (<40 years) analysis of 58 single nucleotide polymorphisms in 580 individuals based on total degenerative disc score
|IJOCP | Volume – 2015| Issue – 2015| Article ID – 2015:81
Conference: Indian Orthopaedic Association Annual Conference IOACON-2013, India [Click for Full details]
Authors: Kanna R, Senthil R M
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Introduction: Degenerative disc disease (DDD) is a common condition that increases with aging. Although the exact mechanisms that lead to DDD are not well understood, a significant genetic influence has been found. Focusing on DDD that occurs in young adults can be valuable in determining the exact role of genetic predisposition to DD. The present study was undertaken to assess the association between single nucleotide polymorphisms of candidate genes in a cohort of young Indian adults.
Methods: We selected young patients (age < 40 years) with lumbar disc degeneration and evaluated them with MRI imaging and Genetic association studies for 58 SNPs of 35 candidate genes. Disc degeneration of individual discs of lumbar spine from L1 to S1 was quantified by Pfirmann’s grading in MRI images (1.5 Tesla). The subjects were stratified into three groups based on a Total Degenerative Disc Score (TDDS). TDDS was developed by adding the individual scores of Pfirmann grading of all the five lumbar discs. Based on the TDDS, the severity of DDD among the subjects was classified as mild (TDDS < 10), moderate (TDDS of 10 to 15) and severe (TDDS > 15). The patients were classified into three groups so that the extreme confounding patients in the mild and severe TDDS groups will automatically fall into the moderate TDDS group. For the final association analysis, only the results of mild (the unaffected, control group) and severe TDDS groups (affected, case group) were compared and analyzed.
Results: The study population comprised of 580 subjects including 308 patients with mild TDDS, 211 patients with moderate TDDS and 61 patients with severe TDDS. There was no significant difference in the gender difference and the mean age of the both groups. To identify the SNPs associated with early accelerated DDD, association analysis was performed using only the mild and severe TDDS groups for reasons stated above. Three of the 35 candidate genes showed significant association with severe TDDS. SNPs viz., rs1940044of MMP (Matrix Metalloproteinase 7), rs2300496 SNP and rs3213718 SNPs of CALM1 (Calmodulin) and rs5277 of COX 2 (Cyclooxygenase) were found to be significantly associated with severe TDDS. Among the previously reported candidate genes, our analysis in the young Indian population had revealed that SNPs ofCOL 9, SKT, CHST 3, CILP, IGFR, SOXp, BMP, MMP 2-12, ADH2, IL1RN, AGC 1, ADAMTS5, NGFB, GLI, HHIP, TAC1 and IL1B were not significantly associated with severe TDDS.
Conclusion: This is the first of its kind in studying the genetic aspects of disc degeneration in the Indian population. The study identifies specific SNP associations of three genes (MMP 7, CALM 1 and COX2) in young adults with severe lumbar disc degeneration. This also shows that disc degeneration is a complex disease with an intricate interplay of multiple genetic polymorphisms.
|How to Cite this Abstract|
|Kanna R, Senthil R M. Genetic susceptibility of lumbar degenerative disc disease in young adults (<40 years) analysis of 58 single nucleotide polymorphisms in 580 individuals based on total degenerative disc score. International Journal of Conference Proceedings 2015;(2015):81|