SMI‐34 is raised against hyperphosphorylated neurofilaments (Covance, USA) and been found to recognize intraneuronal pathological Tau paired helical filaments (PHF‐tau/Alzheimer disease tangles) (32) and to be a marker of Purkinje cell damage in Post‐mortem human brain (33). The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.