Prevalence of HLA-B27 in the New Zealand population: effect of age and ethnicity.

Abstract

INTRODUCTION:

HLA-B27 genotyping is commonly used to support a diagnosis of ankylosing spondylitis (AS). A recent study has suggested that HLA-B27 may adversely affect longevity. The objectives of this study were to determine, for the first time, the prevalence of HLA-B27 in the New Zealand population, and to test whether HLA-B27 prevalence declines with age.

METHODS:

117 Caucasian controls, 111 New Zealand Māori controls, and 176 AS patients were directly genotyped for HLA-B27 using PCR-SSP. These participants and a further 1103 Caucasian controls were genotyped for the HLA-B27 tagging single nucleotide polymorphisms (SNPs) rs4349859 and rs116488202. All AS patients testing positive for HLA-B27 of New Zealand Māori ancestry underwent high resolution typing to determine sub-allele status.

RESULTS:

HLA-B27 prevalence was 9.2% in New Zealand Caucasian controls and 6.5% in Māori controls. No decline in HLA-B27 prevalence with age was detected in Caucasian controls (p = 0.92). Concordance between HLA-B27 and SNP genotypes was 98.7-99.3% in Caucasians and 76.9-86% in Māori. Of the 14 AS patients of Māori ancestry, 1 was negative for HLA-B27, 10 were positive for HLAB*2705, and 3 positive for HLAB*2704. All cases of genotype discordance were explained by the presence of HLAB*2704.

CONCLUSIONS:

HLA-B27 prevalence in New Zealand Caucasians is consistent with that of Northern European populations and did not decline with increasing age. In Māori with AS who were HLA-B27 positive, 76.9% were positive for HLA-B*2705, suggesting that genetic susceptibility to AS in Māori is primarily due to admixture with Caucasians.

• Authors: Rebecca L Roberts, Mary C Wallace, Gregory T Jones, Andre M van Rij, Tony R Merriman, Andrew Harrison, Douglas White, Lisa K Stamp, Daniel Ching, John Highton, Simon M Stebbings
• Journal: Arthritis research & therapy (Arthritis Res Ther) Vol. 15 Issue 5 Pg. R158 (Oct 22 2013) ISSN: 1478-6362 [Electronic] England
• PMID: 24286455 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• HLA-B*27:05 antigen
• HLA-B27 Antigen

Topics

• Adult
• Aged
• Female
• Gene Frequency
• Genetic Predisposition to Disease (genetics)
• HLA-B27 Antigen (genetics)
• Humans
• Male
• Middle Aged
• Native Hawaiian or Other Pacific Islander (genetics)
• New Zealand (epidemiology)
• Polymorphism, Single Nucleotide
• Prevalence
• Spondylitis, Ankylosing (ethnology, genetics)
• White People (genetics)