
Here I present: “Ankylosing Spondylitis”, Victor McKusick, Mendelian Inheritance in Man’, 1966. (AS).
INTRODUCTION.
Ankylosing spondylitis (AS) is a type of arthritis from the disease spectrum of axial spondyloarthritis. is characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. With AS, eye and bowel problems—as well as back pain—may occur. Joint mobility in the affected areas sometimes worsens over time. Ankylosing spondylitis is believed to involve a combination of genetic and environmental factors. More than 90% of people affected have a specific human leukocyte antigen known as the HLA-B27 antigen. The underlying mechanism is believed to be autoimmune or auto inflammatory. Diagnosis is based on symptoms with support from medical imaging and blood tests. AS is a type of seronegative spondyloarthropathy, meaning that tests show no presence of rheumatoid factor (RF) antibodies.
Spondyloarthropathy (SpA), one of the commonest chronic rheumatic diseases, includes a spectrum of related disorders comprising the prototype ankylosing spondylitis (AS), a subset of psoriatic arthritis (PsA), reactive arthritis (ReA), arthritis associated with inflammatory bowel disease, and undifferentiated spondyloarthropathy.
There is evidence that susceptibility to spondyloarthropathy type-1 (SPDA1) can be conferred by variation in the HLA-B27 allele on cytogenetic location 6p21.33 and genomic coordinates 6:31,353,875-31,357,179. The screenshot of the HLA-B27 gene 3,305 bp (base pairs) of DNA sequence length is shown BELOW. Nine (9) other genes besides HLA-B27 in the 6p21.33 cytogenetic location are listed BENEATH.
| Coordinate | Symbol | Genomic Name |
| 6:31,158,589 | TCF19 | Transcription factor-19 (SC1) |
| 6:31,164,337 | POU5F1 | Pou domain, class 5, transcription factor 1 (octamer-binding transcription factor 3) |
| 6:31,173,735 | PSORS1C3 | Psoriasis susceptibility 1 candidate 3, noncoding |
| 6:31,268,749 | HLA-C | Major histocompatibility complex, class I, C |
| 6:31,353,875 | HLA-B | Major histocompatibility complex, class I, B |
| 6:31,400,711 | MICA | MHC class I polypeptide-related sequence A |
| 6:31,463,180 | HCP5 | Major histocompatibility complex, class I, gene P5-1 |
| 6:31,494,918 | MICB | MHC class I polypeptide-related sequence B |
| 6:31,528,962 | MCCD1 | Mitochondrial coiled-coil domain 1 |
| 6:31,530,226 | DDX39B | DExD-box helicase 39B |

