Five of fifty (1.8%) patients with neutropenia had characteristics of Felty Syndrome, i.e., neutropenia plus RF+ and/or ACPA+, but just one of the three classic features (RA, FR+ and ACPA+, neutropenia and splenomegaly), for a prevalence of 0.3% of the total of patients. This evidence concerns the gene PRTN3 and rheumatoid arthritis.