SAT0543 PREVALENCE OF FABRY’S DISEASE IN MILD AND SEVERE FMF PATIENTS
Authors: S. Uslu, G. Kabadayi, P. Teke Kisa, T. Yüce İnel, Z. Arslan, N. Arslan, S. Akar, F. Onen, İ. Sari
Journal: Annals of the Rheumatic Diseases (2020)

Background: Fabry disease (FD) is a rare metabolic disorder caused by the mutations in the α-galactosidase A (GLA) gene. FD patients present with heterogeneous clinical manifestations, which may overlap with systemic diseases including familial Mediterranean fever (FMF). Recurrent episodes of fever, abdominal pain, and arthralgias can be observed in both disorders and this may lead to misdiagnosis. Objectives: To investigate FD prevalence in mild and severe FMF patients. Methods: A total of 66 FMF patients, according to the Tel-Hashomer criteria, were included in the study. Patients were grouped into mild (Group 1) and severe (Group 2) subsets according to the severity score. α-GLA enzyme activity and mutations in the GLA gene were performed. Demographic features, clinical findings, MEFV mutations and treatments were recorded. Results: The clinical and demographical characteristics of the patients were given in Table 1. In severe form, 27 patients were using biological drug and 40.7% had amyloidosis. Symptoms related to FD including hypohidrosis, acroparesthesias, and painful neuropathies, were not different between the groups. Only one patient in group 1 had a low GLA enzyme activity (0.1 nmol/h/ml;Normal &gt;2.5) which also had mutations in the GLA gene but MEFV mutation test was negative. (Table 2). This patient was a 39-year-old female with recurrent abdominal pain, distal extremity pain and the presence of fever during the attacks. She was heterozygous for R301Q. In detailed history, she reported mild acroparesthesias, hypohidrosis, and tinnitus. Table 1. Demographic and clinical findings All patients n: 66 Group 1 n: 32 Group 2 n: 34 p-value Age, median (min./max.) 34 (17/64) 27 (17/59) 36 (18/64) 0.192 Male, n (%) 36 (54.5) 14 (43.8) 22 (64.7) 0.137 Disease duration, median (min./max.) 20.5 (1/57) 12.5 (2/50) 25 (1/57) 0.006 Family history of FMF, n (%) 41 (62.1) 22 (68.8) 19 (57.6) 0.443 Alpha-galactosidase A (nmol/h/ml), median (min./max.) 5.9 (0.1/16) 5.6 (0.1/9.6) 6 (3.1/16) 0.330 Abdominal pain, n (%) 58 (87.9) 31 (96.9) 27 (79.4) 0.030 Fever, n (%) 54 (81.8) 25 (78.1) 29 (85.3) 0.532 Arthritis, n (%) 34 (51.5) 10 (31.3) 24 (70.6) 0.003 Pleuritis, n (%) 31 (47) 19 (59.4) 12 (35.3) 0.083 Painful neuropathy, n (%) 23 (34.8) 13 (40.6) 10 (29.4) 0.440 Acroparesthesias, n (%) 9 (13.6) 6 (18.8) 3 (8.8) 0.240 Angiokeratomas, n (%) 0 (0) 0 (0) 0 (0) - Cardiac abnormalities 1 (1.5) 1 (3,1) 0 (0) 0.485 Tinnitus, n (%) 4 (6.1) 3 (9.4) 1 (2.9) 0.274 Hearing loss, n (%) 2 (3) 2 (6.2) 0 0.086 Hypohydrozis, n (%) 2 (3) 1 (3.1) 1 (2.9) 0.965 Cornea verticillata, n (%) 0 (0) 0 (0) 0 (0) - Proteinüria, n (%) 13 (19.7) 2 (6.3) 11 (32.4) 0.012 Colchine dosing (mg/day), median (min./max.) 2 (1/3) 1 (1/2) 2 (1/3) &lt;0.001 Table 2. MEFV mutant alleles and GLA mutations All patients n: 66 Group 1 n: 32 Group 2 n: 34 Alpha -galactosidase A ( GLA ) gene mutations, n (%) 1 (1.5) 1 (3.1) 0 (0) M694V mutations, n (%) 47 (35.6) 17 (26.5) 30 (44.1) Non-M694V mutations, n(%) 36(27.2) 20 (31.2) 16 (23.5) Conclusion: In this study, we showed the following: 1) the FD rate in the total FMF group was 1.5% (3.1% in group 1), 2) none of the patients in the severe FMF subset had abnormal enzyme activity or mutations related with FD, 3) symptoms related with FD such as hearing loss, hypohidrosis, acroparesthesias, and painful neuropathies also noted in FMF patients particularly in the milder group. Based on our results, FD should be considered in the differential diagnosis of FMF particularly in patients with atypical symptoms. Disclosure of Interests: None declared