The high percentage (66.61%) of patients with unidentified mutations could be due to mutations in the rest of the coding or noncoding MEFV gene or due to mutations in other genes that are also causing Hereditary Recurrent Fevers.
We investigated the hypothesis that low-penetrance mutations in genes (TNFRSF1A, MEFV and NALP3/CIAS1) associated with hereditary periodic fever syndromes (HPFs) might be risk factors for AA amyloidosis among patients with chronic inflammatory disorders, including rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), Crohn's disease, undiagnosed recurrent fevers and HPFs themselves.
We conclude that the new H478YMEFV mutation is the dominant pathological variant causing the inflammatory periodic syndrome in this kindred and that full-length analyses of the MEFV gene are needed to obtain an adequate diagnosis of patients with clinical suspicion of a hereditary periodic fever syndrome, especially those from non-ancestral populations.