👤 Minna Männikkö

Low back pain (LBP) is a common disabling condition. Lumbar disc degeneration (LDD) may be a contributing factor for LBP. Modic change (MC), a distinct phenotype of LDD, is presented as a pathological bone marrow signal change adjacent to vertebral endplate on MRI. It is strongly associated with LBP and has heritability around 30%. Our objective was to identify genetic loci associated with MC using a genome-wide meta-analysis. Presence of MC was evaluated in lumbar MRI in the Northern Finland Birth Cohort 1966 (n=1182) and TwinsUK (n=647). Genome-wide association analyses were carried out using linear regression model. Inverse-variance weighting approach was used in the meta-analysis. A locus associated with MC (p<5e-8) was found on chromosome 9 with the lead SNP rs1934268 in an intron of the Show less

Childhood-onset primary osteoporosis is manifested as reduced bone mineral density, peripheral fractures and/or vertebral compression fractures. Until now, only mutations in LRP5 have been shown to cause the disorder. Candidate gene analyses were performed on 15 patients with primary osteoporosis and 80 healthy controls using CSGE and sequencing. The genes studied included DKK1, DKK2, WNT3A, WNT10B, AXIN1, SOST, TPH1 and 5-HTR1B. Two rare variants in WNT3A (c.152A > G, p.K51R) and DKK1 (c.359G > T, p.R120L) were identified in two patients and their affected family members, but not in control subjects, suggesting a significance for the skeletal phenotype. The in vitro studies of variants showed reduced signaling activity in p.K51R-Wnt3a, while no differences were observed between the WT and variant forms of DKK1. This study addresses the role of other components of the canonical Wnt signaling pathway besides LRP5 in primary osteoporosis, and putatively associates WNT3A and DKK1 variants with the disorder. Future functional studies are needed to elucidate the functional effects of the variants. Show less