# Case Report: Early-onset mevalonic aciduria in neonates with inflammatory marker elevated

## TL;DR

This case report describes a rare neonatal condition called mevalonic aciduria, highlighting its symptoms and a new genetic mutation.

## Contribution

The study reports a novel homozygous MVK gene mutation in a neonate with early-onset mevalonic aciduria.

## Key findings

- A neonate with elevated inflammatory markers was diagnosed with mevalonic aciduria via ELISA and genome sequencing.
- A new MVK gene mutation (c.928G>A, p.Val310Met) was identified as the cause of the condition.
- The case expands the known clinical and genetic spectrum of mevalonic aciduria in neonates.

## Abstract

The aim of this study was to present a case of early-onset mevalonic aciduria (MA) in a neonate and summarize the relevant phenotypic and genotypic spectra of MA.

We describe a neonate who presented with elevated inflammatory marker after birth. Liver function tests revealed liver injury, and enzyme-linked immunosorbent assay (ELISA) confirmed increased mevalonic acid levels in blood and urine. Whole-genome sequencing identified a novel homozygous mutation (c.928G>A, p.Val310Met) in the MVK gene. To date, only 16 neonate cases of MA have been reported in the literature. Affected individuals typically present recurrent fever, hepatosplenomegaly, lymphadenopathy, vomiting, diarrhea, and neurological damage symptoms. This case emphasizes that in patients presenting with recurrent fever accompanied by vomiting, diarrhea, hepatosplenomegaly, and lymphadenopathy, clinicians should pay close attention to differentiating MA from infectious diseases and autoinflammatory disorders to avoid misdiagnosis or underdiagnosis.

We report one of the youngest neonates with early-onset MA diagnosed promptly, caused by the novel homozygous MVK variant, c.928G>A (p.Val310Met), and expand the genotypic and clinical phenotypic spectrum of MVK variants related with MA.