Carriers of the aspartylglucosaminuria genetic mutation and chronic arthritis

Abstract

Objective: To ascertain whether being a carrier of an autosomal recessive disease, aspartylglucosaminuria (AGU), predisposes to chronic arthritis, as does AGU disease.

Methods: A group of 173 unrelated patients with rheumatoid arthritis (RA) but with no family members with AGU each gave a blood sample for AGUFin major mutation DNA analysis. A group of 131 AGU carriers who were parents of patients with AGU completed a questionnaire on joint symptoms and gave a blood sample for rheumatoid factor (RF) analysis. Eight RF positive parents with prolonged joint symptoms had a rheumatological evaluation.

Results: Six patients (1/28) with RA were carriers of the AGUFin major mutation, whereas the carrier frequency among Finns in general is 1/50 to 1/85. Three AGU carriers had chronic arthritis (2.3%), and 17 (13%) were RF positive; the respective percentages among Finns in general are 1.4% and 5%.

Conclusion: As for AGU disease, carrier status may also predispose to chronic arthritis.

Figure 1

Prevalence, with 95% confidence intervals, of the AGUFin major mutation among Finns. Samples 1–5 (samples 4 and 5 are from the same study) are from earlier studies.^4–7 RA, Patients with rheumatoid arthritis.