Reducing body myopathy (RBM) is a rare pathologically defined myopathy characterized by
the presence of inclusion bodies which are abnormally stained by menadione–nitroblue–
tetrazolium. The clinical symptoms vary widely as to the age of onset, disease progression
and severity. Among the many reported patients, there have been only three families with
this disorder, showing a manifold of clinicopathological features in each family. We report a
fourth family with RBM affecting a boy and his mother. The proband (boy) began to have …