The anti-U1-RNP-positive patients were younger (p < 0.0001), had a shorter duration of SLE (p < 0.0001), more often fulfilled the hematologic disorder criteria of the American College of Rheumatology (ACR) (p = 0.04) and had an increased frequency of RP (p = 0.03). This evidence concerns the gene SNRNP70 and systemic lupus erythematosus.