Subacute sclerosing panencephalitis in two brothers.

We report the occurrence of subacute sclerosing panencephalitis (SSPE) in two brothers two years after measles infection. The diagnosis was confirmed by compatible data from medical history, occurrence of autochthonic measles virus (MV) IgG production in the central nervous system (CNS), and pathognomonic EEG changes. Pathogenetically, SSPE is caused by a genome mutation of intracellularly persisting MV, causing viral nucleocapsides to accumulate in the brain cells. A specific predisposing immune defect is not known. The occurrence of two cases in one family is suggestive of a genetic predisposing factor.