TY - JOUR T1 - Genetic Markers in a Medieval Case of Ankylosing Spondylitis JF - The Journal of Rheumatology JO - J Rheumatol SP - 679 LP - 681 DO - 10.3899/jrheum.151170 VL - 43 IS - 3 AU - IMANOL MARTÍN LAZA AU - MONTSERRAT HERVELLA AU - CONCEPCIÓN DE-LA-RÚA Y1 - 2016/03/01 UR - http://www.jrheum.org/content/43/3/679.abstract N2 - To the Editor:Ankylosing spondylitis (AS) is a chronic rheumatic autoimmune disease that affects mainly the sacroiliac joints and spine, where it causes ankylosis through processes of inflammation and ossification. Although the exact accurate etiology of AS is unknown, the disease’s development has been shown to be influenced by genetic factors. The HLA-B27 allele is the strongest genetic marker associated with AS1, but there are other genes both within and outside the MHC that are involved in the development of AS. The most significant laboratory test in the diagnosis of AS involves detecting the presence of the allele HLA-B27, because 90–95% of patients with AS have this allele2. Nevertheless, this allele is found in about 10% of the world’s population; of them, only 5% ultimately develop this disease2. This means that when there are several radiological and clinical symptoms, detecting the allele HLA-B27 is not enough to diagnose the disorder.The aim of our study was to identify several genetic markers associated with the development of AS [HLA-B27 allele and single–nucleotide polymorphisms (SNP) in interleukin 23R (IL-23R) and … Address correspondence to I. Martín Laza, Department of Genetics, Physical Anthropology, and Animal Physiology, UPV/EHU, Barrio Sarriena s/n 48940 Leioa, Bizkaia, Spain. E-mail: imanol.martinl{at}ehu.es ER -