Niemann-Pick type A disease with new mutation: A case report

J Med Case Rep. 2022 Jul 27;16(1):288. doi: 10.1186/s13256-022-03486-5.

PMID: 35883096

Fatemeh Aghamahdi, Matineh Nirouei, Shahram Savad

Highlights: This presentation describes a 1-year-old boy with neurodevelopmental delay, hepatosplenomegaly, and severe hypotonia.

Abstract

Background: Niemann-Pick type A (NP-A) is a congenital, inherited condition brought on by a deficiency of the lysosomal enzyme acid sphingomyelinase. Due to this deficiency, sphingomyelin builds up in lysosomes, which causes cellular apoptosis, hepatosplenomegaly, neurological disorders, and failure to thrive. Other symptoms of the disease that aid in identification include cherry-red spots in the macula and foamy cells in the bone marrow. Type A is a rare, incurable disease with early symptoms and a dismal prognosis; babies seldom survive for more than two years.

Case presentation: A 1-year-old Persian boy with abdominal distention and slow weight gain was referred to the clinic. He was the first male offspring of consanguineous parents. Hepatosplenomegaly, severe hypotonia, breathing difficulties, a slightly coarse face with an open mouth, and a protruding tongue were among findings. The coarse facial features led to the original diagnosis of clinical mucopolysaccharidosis (MPS), however additional testing ruled out this genetic condition. Acid sphingomyelinase levels were lower than usual, according to enzyme histochemistry. Next-generation sequencing of the patient's DNA's coding exons and surrounding intronic regions revealed a homozygous c.682T>G variant in the SMPD1 gene during the genetic analysis. The classification for this variant was "variant of unknown significance." Additional analysis of his parents' DNA extracts using Sanger sequencing revealed that both of his parents' SMPD1 genes were heterozygous for the c.682T>G variant.

Conclusions: This article presents a case of a 1-year-old kid with significant hypotonia, hepatosplenomegaly, and neurodevelopmental delay. A further study revealed a novel mutation for Niemann-Pick disease.

Keywords: Acid sphingomyelinase, Case report, Hypotonia, Neurodegenerative disorder, Niemann-Pick type A