Lack of association of a restriction fragment length polymorphism for serum amyloid P gene with reactive amyloidosis.

The prevalence of a recently described restriction fragment length polymorphism using Msp I for the serum amyloid P gene was determined in 5 groups of patients. Patients with reactive (secondary) amyloidosis, juvenile rheumatoid arthritis, related inflammatory conditions, or juvenile rheumatoid arthritis with reactive amyloidosis, and healthy control subjects were found to be polymorphic for 8.8-kb and 5.6-kb gene fragments; they either had one or the other or both fragments. No significant differences were seen between these groups with relation to this polymorphism, and no correlation with the presence of reactive amyloidosis was observed.