ALCAM and CD6 — multiple sclerosis risk factors

• ALCAM polymorphisms may have influence on risk, development and progression of MS.
• Genotype AA in rs12360861G>A locus of CD6 seems to be protective against MS.
• SNP rs17824933 of CD6 seems to be associated with MS progression.
• Difference in mRNA expression of CD6 between MS patients and controls was found.

ALCAM and CD6 may play an important role in the pathogenesis of multiple sclerosis (MS), since they are involved in the transmigration of leukocytes across the blood–brain barrier. In this study, we confirmed our previous findings about the association of the ALCAM gene with risk, development and progression of MS. Additionally, we showed that in the case of the CD6 gene (encoding receptor of ALCAM) not only polymorphisms but also mRNA expression level are associated with MS. Our analysis revealed that the risk of the disease for AA individuals in rs12360861 was almost 3.0-fold lower in comparison to GG individuals (OR = 0.34; CI95% = 0.12; 0.81). Moreover, we observed lower expression of CD6 mRNA in patients than in healthy individuals (T22,74 = 6.678; p = 0.002).