BACKGROUND: Familial Mediterranean Fever (FMF), characterized by recurrent fever 
and inflammation of serous membranes, is an autosomal recessive disease caused 
by mutations in the Mediterranean fever (MEFV) gene. Around 296 mutations have 
been reported to date.
METHODS: Two two-generation Turkish families with a total of four members 
diagnosed with FMF clinically were screened with DNA sequencing performed on 
exon 2 and exon 10 of the MEFV genes. Then, complete exome sequencing analysis 
of MEFV gene was done for four patients in whom novel mutation was detected.
RESULTS: A novel single base Guanine (G) insertion mutation in the coding region 
of MEFV gene, named c.2330dupG (p.Gln778Serfs*4 or Q778SfsX4) resulting in a 
mutated Pyrin/Marenostrin protein was identified.
CONCLUSIONS: This is the first report of a new mutation in exon 10 of the MEFV 
gene in two Turkish families. This novel pattern of insertion mutation may 
provide important information for further studies on FMF pathogenesis.