Arthritis Res Ther. 2013 Oct 22;15(5):R158. doi: 10.1186/ar4341.
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.
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.
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 HLAB2705, and 3 positive for HLAB2704. All cases of genotype discordance were explained by the presence of HLAB*2704.
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.
HLA-B27 基因分型常用于支持强直性脊柱炎（AS）的诊断。最近的一项研究表明，HLA-B27 可能会对寿命产生不利影响。本研究的目的是首次确定新西兰人群中 HLA-B27 的患病率，并检验 HLA-B27 患病率是否随年龄增长而下降。
117 名白种人对照组、111 名新西兰毛利人对照组和 176 名 AS 患者直接采用 PCR-SSP 对 HLA-B27 进行基因分型。这些参与者和另外 1103 名白种人对照组对 HLA-B27 标记单核苷酸多态性（SNP）rs4349859 和 rs116488202 进行基因分型。所有检测到新西兰毛利人 HLA-B27 阳性的 AS 患者均进行高分辨率分型以确定亚等位基因状态。
新西兰白种人对照组 HLA-B27 患病率为 9.2%，毛利人对照组为 6.5%。在白种人对照组中未发现 HLA-B27 患病率随年龄增长而下降（p = 0.92）。在白种人中，HLA-B27 与 SNP 基因型之间的一致性为 98.7-99.3%，在毛利人中为 76.9-86%。14 名毛利人 AS 患者中，1 例 HLA-B27 阴性，10 例 HLA-B2705 阳性，3 例 HLA-B2704 阳性。所有基因型不一致的病例均由 HLA-B*2704 的存在解释。
新西兰白种人 HLA-B27 的患病率与北欧人群一致，且不随年龄增长而下降。在 HLA-B27 阳性的 AS 毛利人中，76.9% 为 HLA-B*2705 阳性，这表明毛利人患 AS 的遗传易感性主要是由于与白种人混合。
