A novel, non-functional, COL1A1 polymorphism is not associated with lumbar disk disease in young male Greek subjects unlike that of the Sp1 site.

OBJECTIVE We recently reported the association of the Sp1 site polymorphism of the COL1A1 gene with lumbar disk disease (LDD). In the present study we searched for a different polymorphism of the COL1A1 gene (which is usually not in linkage disequilibrium with the Sp1 site) in subjects with LDD. DESIGN Blood was collected from 24 Greek army recruits, aged 29+/-7.6 years, with LDD, and 66 healthy men, aged 26+/-4.38 years, matched for body mass index (BMI) and age, with normal BMD and with no history of trauma or fractures, who served as controls. DNA was extracted and the COL1A1 gene was sequenced. Of the control subjects, 12 were army recruits and 54 were selected from the general population. RESULTS The four base-pair insertion polymorphism in the COL1A1 gene analyzed by polymerase chain reaction amplification of DNA produces two different fragments (alleles A1 and A2): 14 patients (58.3%) were homozygous for A2A2, versus 35 controls (53%), while 3 patients (12.5%) were A1A1, and 8 of the control subjects (12%) had this genotype. There were no statistically significant differences in the presence of the two alleles of this polymorphism between patients with LDD and control subjects. CONCLUSIONS A four base-pair insertion polymorphism of the COL1A1 gene is not associated with the presence of LDD in young males, unlike the Sp1 site polymorphism of the same gene. These data reinforce the association between LDD and the functional polymorphisms of the Sp1 site by showing that other polymorphic sites of the of the COL1A1 gene in the same population of patients are not linked to the disease.