The case of a patient is described who showed slowly progressive mental deterioration with generalized muscular spasticity. No ocular manifestations were observed at any time. Death occurred at the age of 35 years. The patient was the seventh in a sibship of 12, 4 members of which were similarly affected.At pathologic examination, the characteristic picture of a ubiquitous neuronal lipidosis was found.The case is considered to be an instance of so-called late amaurotic idiocy. The main features of the disease are briefly discussed.Abstract Teaser