Gender-specific haplotype association of collagen α2 (XI) gene in ossification of the posterior longitudinal ligament of the spine.

Abstract Among Japanese, ossification of the posterior longitudinal ligament of the spine (OPLL) is a leading cause of myelopathy, showing ectopic bone formation in the paravertebral ligament. We have provided genetic evidence that the collagen alpha2 (XI) (COLllA2) locus of chromosome 6 constitutes susceptibility for OPLL. Five distinct single nucleotide polymorphisms (SNPs), identified in COLllA2, were combined to construct possible haplotypes by the use of a maximum likelihood program. Estimated haplotype frequency was compared in OPLL patients and non-OPLL controls. We report a gender-specific association of the COLllA2 haplotype with OPLL. The frequency of the most commonly observed haplotype was significantly higher in male patients (P = 0.0003) compared with controls, but not in female patients (P = 0.21). OPLL is predominantly observed in males, with a prevalence ratio of 2:1, and our gender-specific associations indicate that genetic factors involving COLllA2 play... [ABSTRACT FROM AUTHOR]