Androgen receptor genetic variants in male patients with ankylosing spondylitis in Taiwan
Correspondence: Professor Hong-Yo Kang, Graduate Institute of Clinical Medical Sciences and Center for Menopause and Reproductive Research, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Kaohsiung, Taiwan.
Ankylosing spondylitis (AS) is a chronic rheumatic disorder with gender differences. The aim of study was to investigate the association between polymorphisms of the androgen receptor (AR) gene and the susceptibility to AS in Taiwanese men of Han Chinese descent.
We conducted a case-control study with 92 male AS patients and 108 healthy controls. Trinucleotide (CAG and GGC) repeats and seven single nucleotide polymorphisms (SNPs) rs962458, rs6152, rs1204038, rs5918757, rs2361634, rs6624304 and rs1337080 in the AR gene were genotyped.
We found that only one patient had polymorphic SNPs of the AR gene. None of the genotyped SNPs in the AR gene, originally found in Caucasians, was polymorphic in the Taiwanese men. Neither CAG nor GGC repeat lengths in the AR gene had a significant relationship with human leukocyte antigen (HLA)-B27 positivity or disease severity in AS.
There were no differences in CAG and GGC lengths in the AR gene between AS and the controls. None of the genotyped SNPs in AR gene are detected to be polymorphic in male Taiwanese, which indicates that the effect of AR gene on AS may be ethnic-specific and may be conserved in East Asians compared to Caucasian populations. Still, additional studies using large sets of subjects deserve further attention, since our sample size was small with limited statistical power and supporting evidence for association between the AR gene and AS risk in the Japanese population exists.