Misdiagnosis of familial Mediterranean fever in patients with Anderson-Fabrydisease

Fabry disease (FD) is an underdiagnosed pathology due to its symptomatology that overlaps with various systemic and rheumatic disorders, including familialMediterranean fever (FMF). We examined the Mediterranean fever (MEFV) andα-galactosidase A (GLA) genes, whose mutations are responsible for FMF and FD,respectively, in 42 unrelated patients diagnosed with FMF, which revealedsignificant ambiguity regarding some of the symptoms which are also present inFD. The objective of this study was to determine the spectrum of mutationspresent in these genes, in order to identify cases of mistaken diagnosis of FMFand/or missed diagnosis of FD. Ten out of 42 patients had one mutation inhomozygosis or two different mutations in heterozygosis in the MEFV gene; 20/42had a single heterozygous mutation, and 12/42 did not have genetic alterations inMEFV. The analysis of the GLA gene conducted on all the samples revealed thatthree subjects, and some members of their families, had two different exonicmutations associated with FD. Family studies allowed us to identify eight othercases of FD, bringing the total undiagnosed subjects to 11/53. Analyzing the MEFVand GLA genes in patients with clinical diagnoses of FMF proved to befundamentally important for the reduction of diagnostic errors.