Supplement 5: Correlation of the genotypes with the IFN score

Among the SSc cases, the presence of the GG or GT genotypes of IFNAR2 rs7279064 were significantly associated with higher IFN score (p=0.008), which remained significant after correction for ethnicity (p=0.032). The IFN score did not vary significantly by the investigated SNP in the control group. The mean difference ± SE of the IFN score between SSc patients with TT/GT versus GG genotype was 7.34±0.9 whereas the mean difference ± SE in the control group was only 0.37 ± 1.06.

Other SNPs (IFNAR2 rs4986956 , STAT1 rs1914408, STAT4 rs11889341, rs6752770, IRF7 rs1061502, IFNAR1 rs17875834, rs2257167, IRF5 rs729302, rs2004640 and rs752637) did not correlate with the IFN score among the SSc patients or controls (table 2). We did not investigate the correlation of these SNP’s with the IFN score among the SLE patients because the small sample size precluded us from a meaningful statistical analysis.

Table 2: Correlation of the investigated genotypes with the IFN score


Gene SNP Study Group Minor Allele Frequency (%) P-Value ‡
rs17875834 SSc* A=0.08 1.0
Control† A=2.4 1.0
rs2257167 SSc C=41.5 0.136
Control G=35.7 0.248
rs4986956 SSc C=4.6 1.0
Control C=16.7 1.0
rs7279064 SSc G=27.3 0.008
Control G=42.9 0.482
rs1914408 SSc A=22.3 0.573
Control A=28.6 0.06
rs11889341 SSc A=25 0.806
Control A=15 0.544
rs6752770 SSc C=28 0.52
Control C=28.6 0.509
rs2004640 SSc A=48.4 0.55
Control A=50
rs729302 SSc C=30.8 0.121
Control C=19 1.0
rs752637 SSc A=44.6 0.054
Control A=42.9 0.763
rs1061502 SSc G=34.6 0.305
Control G=26.2 0.207

*Genomic DNA was available on 66 (91.7%) SSc patients
†Genomic DNA was available on 21 (100%) healthy controls
‡Recessive Model