# Impact of COVID-19 infection in patients with inherited metabolic diseases: a National Multicenter Study from the French IMDs Healthcare Network for Rare Diseases

## TL;DR

This study found that most patients with inherited metabolic diseases had mild to moderate COVID-19, with children more likely to experience metabolic issues than adults.

## Contribution

The study provides new insights into the differential impact of COVID-19 on children versus adults with inherited metabolic diseases.

## Key findings

- Most IMD patients experienced mild to moderate COVID-19 symptoms.
- Children with IMDs were more likely to experience metabolic destabilization than adults.
- Severe outcomes and treatment interruptions were rare in both children and adults.

## Abstract

The COVID-19 pandemic presented unique challenges for patients with inherited metabolic diseases (IMDs), particularly due to the risk of infection-related metabolic decompensation and disruptions to specialized care. We aimed to assess the impact of COVID-19 infection on the clinical course of patients with IMDs in a National Multicenter Study from the French IMDs Healthcare Network for Rare Diseases.

This national French study included 317 IMD patients (69 children and 248 adults) with symptomatic or asymptomatic COVID-19 infection between January 2020 and January 2023. Most COVID-19 cases were mild to moderate. The frequency of symptomatic COVID-19 was similar in adults and children (234/248 [94.3%] vs. 56/64 [87.5%], p = 0.09). Children experienced more frequently metabolic destabilization than adults during a COVID-19 infection (17/67 [25.4%] vs. 33/248 [13.3%], p = 0.03). Moreover, the proportion of children admitted to the ICU was higher than that of adult patients (5/69 [7.2%] vs. 4/248 [1.6%], p = 0.04). Temporary suspension or delay of IMD-specific treatment due to COVID-19 was rare, affecting 3/64 (4.7%) children and 13/229 (5.7%) adults. Severe COVID-19 outcomes were uncommon, with only one death in the adult cohort and five cases of long-term sequelae (1 child, 4 adults).

COVID-19 was generally mild to moderate in IMD patients and caused metabolic decompensation or imbalance in a minority of cases, with only rare interruptions to disease-specific treatment. We observed that COVID-19 more frequently worsened the condition of children with IMD compared to adults in our cohort of patients.

The online version contains supplementary material available at 10.1186/s13023-026-04230-8.