Clinical and molecular diagnosis of Familial Mediterranean Fever in Egyptian children.

BACKGROUND Familial Mediterranean Fever (FMF) is an autosomal inherited disorder affecting certain races including Arabs. Diagnosis depends mainly on clinical basis, but mild forms may remain undiagnosed. OBJECTIVES This study aims at an accurate diagnosis of FMF in Egyptian children by detection of genetic mutations in addition to clinical assessment. SUBJECTS AND METHODS Subjects included 66 Egyptian cases (37 males and 29 females) with a mean age of onset of 6.9 years. They had been referred from health centers and hospitals of the Delta region, Egypt. Analysis of the clinical manifestations was performed using Tel-Hashomer criteria in addition to 10 items clinical score system. For all these cases, DNA analysis was made for three common mutations M680I, M694V, and V726A using amplification refractory mutation system (ARMS-PCR) technique. RESULTS Most of the cases had attacks ranging from 3-5 days duration with the mean of 3.6 days. Their rate of recurrence was variable but 47 % of them had suffered attacks 10-30 times/year. Abdominal pain was the most common symptom (87.9%) followed by fever (82%), arthritis or arthralgia (56.1%), chest pain (45%) and myalgia (6%). Laparotomy had been done during attacks for exploration or appen-dectomy in 27.7% of cases. Positive mutations were detected among 42 cases (63.6%), of them 14 (21.2%) were compound heterozygotes, 7 (10.6%) were had homozygotes while 21 (31.8%) were simple heterozygotes. Allele M694V was the most frequent one (18.8%) followed by V726A (17.4%) and M680I (12.1%). Taking positive mutation as a guide for diagnosis, a cutoff clinical score level was determined with =15 for unlikely, =20 for definite and 15-20 for probable diagnosis. CONCLUSION Diagnosis of FMF among Egyptian children cases although based mainly on clinical suspicion requires to be confirmed through detection of the corresponding mutation which can be easily made using the simple ARMS-PCR technique.