A Family with Late-Onset and Predominant Choreic Niemann Pick Type C: A Treatable Piece in the Etiological Puzzle of Choreas

Abstract

Niemman Pick type C (NPC) is a treatable neurodegenerative lysosomal disorder characterized by the widespread age of onset and clinical presentation. The adult NPC phenotype frequently includes ataxia, supranuclear gaze palsy, and cognitive and behavioral problems.1 Movement disorders are also often observed in these patients. Among them, chorea has been rarely described as a dominant sign.1, 2 On the other hand, a phenotype dominated by chorea and cognitive and behavioral manifestations is suggestive of Huntington's disease (HD).3, 4 The rare cases showing this phenotype proved to be negative for the CAG expansion in HTT and are categorized as Huntington-like disorders (HDL).5 Although the list of HDL genetic etiologies has grown considerably during the past few years, the diagnostic yield for these conditions is still limited.3, 5 Noteworthy, NPC is neither routinely considered in the differential diagnosis of chorea nor among the HDL disorders. We present 2 siblings presenting with a late onset and predominate choreic phenotype, where the final diagnosis was NPC.