Familial paroxysmal polyserositis (familial Mediterranean fever); incidence of amyloidosis and mode of inheritance.

Findings in 120 cases of familial paroxysmal polyserositis from Lebanon are reported. There was a predominance of male and Armenian patients. Symptoms started before age 20 in 82%. Amyloidosis was diagnosed in 9 patients only. Rectal biopsy in 21 consecutive cases with long-standing illness was negative for amyloid. Amyloidosis without polyserositis was not encountered. Proportion of affected sibs (130) was lower than expected (160) for an autosomal recessive gene. Poor penetrance, especially in females could account for this discrepancy.