Clinical disease among patients heterozygous for familial Mediterranean fever

D Marek‐Yagel, Y Berkun, S Padeh… - … : Official Journal of …, 2009 - Wiley Online Library
D Marek‐Yagel, Y Berkun, S Padeh, A Abu, H Reznik‐Wolf, A Livneh, M Pras, E Pras
Arthritis & Rheumatism: Official Journal of the American College …, 2009Wiley Online Library
Objective To define the molecular basis of familial Mediterranean fever (FMF) in patients
with only 1 mutation in the MEFV gene. Methods Genetic analysis was performed in 20 FMF
patients, including full sequencing of complementary DNA (cDNA) samples and multiplex
ligation‐dependent probe amplification analysis. In patients with first‐degree relatives with
FMF, haplotype analysis was also performed. Results A second mutation was found in 2
patients. In the other 18 patients, we could not identify additional mutations, large genomic …
Objective
To define the molecular basis of familial Mediterranean fever (FMF) in patients with only 1 mutation in the MEFV gene.
Methods
Genetic analysis was performed in 20 FMF patients, including full sequencing of complementary DNA (cDNA) samples and multiplex ligation‐dependent probe amplification analysis. In patients with first‐degree relatives with FMF, haplotype analysis was also performed.
Results
A second mutation was found in 2 patients. In the other 18 patients, we could not identify additional mutations, large genomic deletions, or duplications. Analysis of single‐nucleotide polymorphisms along the cDNA ruled out a lack of expression of 1 of the alleles. In 2 of the 3 families in which more than 1 sibling had FMF, we showed that the affected siblings inherited a different MEFV allele from the parent who did not have the MEFV mutation.
Conclusion
These findings are highly consistent with the existence of a clinical phenotype among some patients who are heterozygous for FMF and could explain the vertical transmission in some families. A single mutation in the MEFV gene may be much more common than was previously thought and may include up to 25% of patients who are diagnosed as having FMF.
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