Genetic background may contribute to the latitude-dependent prevalence of dermatomyositis and anti-TIF1-γ autoantibodies in adult patients with myositis

Table 2 Association of polymyositis- or dermatomyositis-associated single-nucleotide polymorphisms with latitude

Variable	Immunochip associations and P values for subgroups			Associations with latitude, adjusted for sex
Variable	Reported gene	Polymyositis	Dermatomyositis	OR (95% CI)	P value
PM associations
rs2476601	PTPN22	7.90 × 10⁻¹¹	0.05	1.08 (1.05, 1.11)	< 0.001
rs4690220	SLC26A1 \| IDUA	7.47 × 10⁻⁶	0.03	1.02 (1.01, 1.02)	0.001
rs7956536	UBE3B \| MMAB	3.66 × 10⁻⁶	0.67	1.01 (1.00, 1.02)	0.004
rs17799348	FAM167A \| BLK	4.13 × 10⁻⁶	0.32	0.99 (0.98, 0.99)	0.035
rs1420095	IL18R1	6.16 × 10⁻⁶	0.87	0.99 (0.98, 1.01)	0.334
rs2286896	NAB1	3.76 × 10⁻⁶	0.58	0.99 (0.98, 1.01)	0.434
rs9905921	LOC728073 \| RPL38	2.01 × 10⁻⁶	0.10	0.99 (0.99, 1.01)	0.748
rs7535818	RGS1	1.37 × 10⁻⁵	0.14	0.99 (0.99, 1.01)	0.897
DM associations
rs4702698	ROPN1L \| ANKRD33B	0.5	4.49 × 10⁻⁶	0.99 (0.98, 0.99)	0.012
rs570676	PRR5L \| TRAF6	0.01	6.23 × 10⁻⁷	0.99 (0.98, 1.00)	0.081

DM Dermatomyositis, PM Polymyositis
All variables were analysed against latitude in an ordered logistic regression analysis, adjusted for sex. Single-nucleotide polymorphisms (SNPs) identified as having suggestively significant P values (P < 2.25 × 10⁻⁵) for either PM or DM in the Immunochip study [8] were used. SNP risk allele frequencies were calculated from the Immunochip study control data (n = 9911)

ISSN: 1478-6362