A survey of phenotype II in familial Mediterranean fever

Objective-Phenotype II in familial Mediterranean fever (FMF) is the onset o f amyloidosis before the onset of FMF with its typical attacks, or as an is olated finding in a member of an FMF family. Its presence was investigated by looking for proteinuria among the asymptomatic relatives of patients wit h FMF complicated by amyloidosis and among the asymptomatic relatives of pa tients with juvenile chronic arthritis (JCA) complicated by amyloidosis, us ed as controls. Methods-The relatives of the index patients (13 with FMF and amyloidosis) a nd controls (6 with JCA and amyloidosis) were screened for proteinuria. Rec tal biopsies were performed when proteinuria was significant (greater than or equal to 300 mg/d). Results-461 relatives were screened in the FMF group and 269 among the cont rols. Two of the FMF relatives and one JCA relative had no symptoms of FMF but had significant proteinuria. Rectal biopsy for amyloidosis was negative in all instances of significant proteinuria. Conclusion-Phenotype II is uncommon among the relatives of patients with FM F and amyloidosis.