Ankylosing spondylitis

Wikipedia has articles on both spondylitis and ankylosing spondylitis, which is basically an autoimmune arthritis of the spine that tends to have its first onset in young adults. It is considered to be highly heritable, with over 90% of the risk of developing the disease being genetically based. It is two to three times more prevalent in men than in women, and men tend to be more severely affected.

A polygenic risk score, based on a weighted summary of 110 SNPs and HLA-B27, was developed based on 164 Norwegian AS patients.[PMID 30936278]

SNPs in at least 3 genes have been fairly strongly implicated in ankylosing spondylitis [PMID 17952073]:

• HLA-B*27, the first and still most prominent association; more than 80% of cases are positive for the HLA-B*27 allele, yet only 1-5% of HLA-B*27 carriers develop ankylosing spondylitis [PMID 23749187]
  

See details at: HLA-B27 Syndromes.

Not all allelles of HLA-B27 are at risk for B27 Syndromes, please check the HLA-B27 page for details.

• Over 40 allelic variants are known, the most common being B*27:05 (tagged by rs116488202)

• The ERAP1 gene, accounting for ~26% of the population attributable risk
  • rs27044
  • rs17482078
  • rs10050860
  • rs30187
  • rs2287987

• The IL23R gene, accounting for ~10% of the population attributable risk
  • rs11209026, also involved in Crohn's disease and inflammatory bowel disease (IBD)
  • rs1004819
  • rs10489629
  • rs11465804
  • rs1343151
  • rs10889677

An additional region on ch 2p15 has been reported and replicated at least once:

• rs10865331

Other SNPs have also been associated with this condition:

• rs2242944
• rs7743761
• rs868213 in the EXOC3L gene
• rs2303138 in the LNPEP gene
• rs7302230 in the CLSTN3 gene
• and two SNPs in the ARTS1 gene (also seen as ARTS-1):
  • rs30187
  • rs10050860