# Intrauterine intestinal obstruction in a preterm infant with severe mevalonate kinase deficiency – a case report

## TL;DR

A preterm infant with severe mevalonate kinase deficiency developed intestinal obstruction and other severe symptoms, highlighting the need for early diagnosis and treatment.

## Contribution

This case report adds to the limited data on neonatal manifestations and outcomes of severe mevalonate kinase deficiency.

## Key findings

- Intrauterine intestinal obstruction was a presenting feature of severe mevalonate kinase deficiency in a preterm infant.
- The infant exhibited elevated urinary mevalonic acid and responded to anti-inflammatory therapy but ultimately died from cardiorespiratory failure.
- The case emphasizes the importance of early diagnostic consideration in the presence of fetal anomalies like hydrops fetalis and microcephaly.

## Abstract

Mevalonate kinase deficiency is an inherited autoinflammatory disorder that can present with a wide clinical spectrum, ranging from mild forms with recurrent episodes of fever, lymphadenopathy, splenomegaly and skin rash to the much rarer severe form, which is characterized by additional occurrences of psychomotor impairment, cholestatic jaundice, ophthalmological symptoms, and failure to thrive. The few cases described with perinatal onset often showed a very severe clinical course.

Here, we report the case of a preterm infant born at 30 + 2 weeks of gestation with a prenatal genetic diagnosis of mevalonate kinase deficiency presenting with intrauterine bowel dilatation, mild hydrops fetalis, and microcephaly. Laparotomy on the second day of life revealed intestinal obstruction necessitating partial ileum resection and ileostomy. The neonate had recurrent inflammatory reactions with elevated C-reactive protein levels, severe cholestasis, a progressive liver dysfunction, and an increasingly distended abdomen with subsequent respiratory insufficiency. Urinary mevalonic acid was highly elevated. The patient received anti-inflammatory therapy with prednisone and anakinra. Unfortunately, the patient died at the age of 77 days due to cardiorespiratory failure.

This case shows that intestinal obstruction with dilated fetal bowel loops can be an initially leading clinical symptom of severe mevalonate kinase deficiency. Diagnostics should be considered at an early stage, especially in the presence of other anomalies such as hydrops fetalis, growth restriction, or microcephaly. Data on the neonatal course of severe mevalonate kinase deficiency are still scarce and further studies are needed, particularly on treatment in neonates and young infants.