# Incidental maternal glutaric aciduria type I detection through newborn screening: A case report

## TL;DR

A mother was unexpectedly diagnosed with a metabolic disorder after her newborn's screening showed a low carnitine level.

## Contribution

This is the first reported case of maternal glutaric aciduria type I detected through newborn screening in France.

## Key findings

- A previously undescribed mutation in the GCDH gene was identified in the mother.
- The mother showed an asymptomatic but high-excretor biochemical profile.
- Newborn screening for carnitine metabolism disorders can lead to incidental maternal diagnoses.

## Abstract

The expansion of newborn screening in France (2023–2025) to include carnitine metabolism disorders has increased false positives, often due to unsuspected maternal metabolic conditions. We report the first french incidental diagnosis of a glutaric acidemia type I in a mother following a low C0 carnitine level detected on her newborn's screening. Genetic analysis revealed a previously undescribed mutation in the GCDH gene at a homozygote state consistent with an asymptomatic but high-excretor biochemical profile.