HLA-B27 is a normal gene but has a strong association with Ankylosing Spondylitis although it’s not entirely clear how it effects the disease as not everyone who has the gene develops AS.
So presence of the gene alone is not a positive diagnosis of AS and in my experince, testing for the gene is not routine although other key symptoms were there for a long time.
I thought the test was something new but at the 2011 NASS conference in Portsmouth a specialist told me the test had been around since the 1970′s and probably cost £20.
According to an article on wikipedia
‘The prevalence of HLA-B27 varies markedly in the general population. For example, about 8% of Caucasians, 4% of North Africans, 2-9% of Chinese, and 0.1-0.5% of persons of Japanese descent possess this gene. In northern Scandinavia (Lapland), 24% of people are HLA-B27 positive, while 1.8% have associated ankylosing spondylitis.’
The Spondylitis Association of America point out that ‘Generally speaking, no more than 2% of people born with this gene will eventually get spondylitis.’
Research is still ongoing in terms of this gene and others that might play a part with AS and you may be able to take part in this research if you have been diagnosed with AS. Contact details are on the NASS website.