Related Articles Phenotypic variability in two patients with tumor necrosis factor receptor associated periodic fever syndrome emphasizes a rare manifestation: Immunoglobulin A nephropathy. Eur J Med Genet. 2020 Apr;63(4):103780 Authors: Balci S, Kisla Ekinci RM, Melek E, Atmis B, Bisgin A, Yilmaz M Abstract Tumor necrosis factor receptor associated periodic fever syndrome (TRAPS) is caused by heterozygote mutations in TNFRSF1A, characterized by recurrent inflammatory attacks. In this report, we described two patients with different heterozygote mutations in TNFRSF1A. Patient 1, a 15-year-old male, had suffered from recurrent fever attacks accompanied by abdominal pain, eye manifestations, and myalgia with increased acute phase reactants since the age of 6-month. He had been unsuccessfully treated with colchicine for having familial Mediterranean fever without an identifiable MEFV mutation since the age of 4-year. At the age of 15 years, he was diagnosed with immunoglobulin (Ig) A nephropathy due to massive proteinuria and renal biopsy findings. Next generation sequencing revealed NM_001065.3: c.236C>T; p. (Thr79Met); T50M heterozygote mutation in TNFRFS1A. He was treated with methylprednisolone and cyclosporine for IgA nephropathy, thereafter with canakinumab for TRAPS. Patient 2, a 17-year-old female, had recurrent arthritis attacks accompanied by increased acute phase reactants for the last two months. She had neither fever attacks nor rashes or myalgia. Her physical examination was normal between attacks. Magnetic resonance imaging of both knees and ankles showed no signs of chronic arthritis. MEFV analyzes showed no mutation. Next generation sequencing revealed NM_001065.3: c.362G>A; p.(Arg121Gln); R92Q heterozygote mutation in TNFRFS1A. Arthritis attacks were treated successfully with ibuprofen thereafter. In conclusion, we wish to emphasize the diversity of the clinical manifestations between these two patients with distinct sequence variants in TNFRSF1A. Moreover, we presented a rare manifestation of TRAPS, IgA nephropathy. PMID: 31586650 [PubMed - indexed for MEDLINE]