Visceral symptoms as a key diagnostic sign for the early infantile form of Niemann-Pick disease type C in a Russian patient: A case report

Abstract

Background: Niemann-Pick disease type C is a rare metabolic disease characterized by progressive neurological deterioration with childhood onset, and often results in premature mortality. Niemann-Pick disease type C has an extremely heterogeneous clinical presentation with a wide range of visceral and neurological signs and symptoms that are not specific to the disease, and which progress over varied periods of time. The incidence and epidemiology of Niemann-Pick disease type C in Russia have not been characterized. We report the case of a Russian newborn with early-infantile onset Niemann-Pick disease type C who displayed prolonged neonatal jaundice and hepatosplenomegaly. Case presentation: A 5-year-old white boy born to non-consanguineous Russian parents was originally diagnosed with galactosemia at the age of 2 months based on a raised blood galactose level. A galactose-free and lactose-free diet resulted in achievement of a normal galactose level, but hepatosplenomegaly and cholestatic signs persisted. Liver biopsy results hinted at possible Niemann-Pick disease type C, but differential diagnostic investigations for progressive familial intrahepatic cholestasis type 2 (Byler syndrome) indicated a heterozygous genotype suggestive of this disease. Further, progressive neurological symptoms prompted additional genetic analyses for possible Niemann-Pick disease type C, from which an as-yet unreported combination of known NPC1 gene mutations was identified, and a final diagnosis of Niemann-Pick disease type C was established. The patient subsequently developed typical neurological symptoms of early-infantile Niemann-Pick disease type C, including vertical supranuclear ophthalmoparesis and cerebellar ataxia. Miglustat therapy was initiated 2.5 years ago, and some improvements in movement and speech have since been observed. Conclusions: This case illustrates the continued challenges associated with diagnosing Niemann-Pick disease type C based on the appearance of nonspecific cholestatic symptoms. Based on this case we recommend examination of all newborns and children who display unexplained cholestasis or isolated splenomegaly/hepatosplenomegaly during the first months of life for other signs of possible Niemann-Pick disease type C.