An Unusual Cause of Renal Dysfunction: AA Amyloidosis with a Heterozygous Mutation of MEFV Gene

A BSTRACT This case report details a 51-year-old man from Andhra Pradesh, India, with a 4-year history of well-controlled hypertension and progressive renal dysfunction over 2 years. Initial evaluation revealed elevated creatinine levels, absent proteinuria, and unremarkable imaging. Kidney biopsy showed amyloid deposits confirmed through Congo red staining and immunohistochemistry, revealing Serum Amyloid-A (SAA) amyloidosis. Genetic analysis identified a heterozygous mutation in the MEFV gene, associated with familial Mediterranean fever (FMF), despite the patient’s lack of classic FMF symptoms or Mediterranean ethnicity. This case underscores the importance of considering Amyloid A amyloidosis in atypical renal dysfunction and highlights the diagnostic value of genetic studies and immunohistochemistry in elucidating rare presentations.