||common in clinvar
||likely to carry one HLA-B27 allele, possible risk for B27 Syndromes.
||likely to carry two HLA-B27 alleles, possible risk for B27 Syndromes.
Perhaps the best known HLA-B27 tag SNP is rs116488202, located about 23kb away from rs3819299, but the former SNP is not tested on many platforms (for example, it is not tested by Ancestry), while the latter is and can be used as a proxy assuming strong enough linkage disequilibrium (which is likely at least in European populations but perhaps not others).
rs3819299 is reported to be associated with a (minor) impact on platelet count, but not with an association to ankylosing spondylitis (which is well reported as associated with HLA-B27).
rs3819299 is cited in this patent as associated with HLA-B*4002 in the JPT population
||New gene functions in megakaryopoiesis and platelet formation.
||5.05 [3.43-6.66] 10^9/l increase