Clinical manifestations and molecular genetics of seven patients with Niemann–Pick type-C: a case series with a novel variant

Abstract Objectives Niemann–Pick type C (NPC) is a rare, autosomal recessive, neurodegenerative disorder caused by biallelic pathogenic variants in the NPC1 or NPC2 genes, leading to lysosomal lipid accumulation. NPC has an incidence of 1 in 100,000 live births and presents with a wide range of symptoms affecting visceral organs and the central nervous system. We aim to describe the diverse clinical presentations of NPC through case studies. Case presentation We report seven NPC patients from five families, showcasing the variability in clinical manifestations. The most common finding was hepatosplenomegaly (70 %), followed by prolonged jaundice (57 %) and neonatal cholestasis. Pulmonary alveolar proteinosis (PAP) was observed in three patients with biallelic pathogenic variants in the NPC2 gene. Neurological symptoms, including vertical gaze palsy and epilepsy, were noted in patients with juvenile onset form. Genetic analyses identified a novel homozygous c.315del (p.Thr106ProfsTer5) variant in the NPC2 gene, associated with early infantile onset. Conclusions NPC presents with diverse clinical findings across ages. Early hepatic symptoms in infants and neuropsychiatric issues in older patients warrant a high index of suspicion for NPC in such cases. A multidisciplinary approach is crucial for patient management, and further research is needed to clarify genotype–phenotype relationships in NPC.