# Mitochondrial complex I deficiency in a 4-year-old boy due to compound heterozygous NDUFV1 mutation: a case report of a new pathogenic variant

## TL;DR

A 4-year-old boy with mitochondrial complex I deficiency had a new harmful mutation in the NDUFV1 gene, causing facial paralysis and balance issues.

## Contribution

The paper reports a novel pathogenic variant in the NDUFV1 gene associated with mitochondrial complex I deficiency.

## Key findings

- Compound heterozygous NDUFV1 mutations c.640G < A and c.248C < T were identified in a patient with mitochondrial complex I deficiency.
- The variant c.248C > T in NDUFV1 was found to have a previously unknown pathogenic effect.
- The patient exhibited left-sided facial paralysis and balance impairment linked to the genetic mutations.

## Abstract

Mutations in the NDUFV1 gene are associated with mitochondrial complex I deficiency and have been linked to various clinical conditions such as Leigh syndrome, severe infantile lactic acidosis, newborn cardiomyopathy, progressive leukoencephalopathy, and other encephalomyopathies. Genetic alterations revealed mitochondrial complex 1 deficiency, nuclear type 4 |AR: two compound heterozygous missense mutations in the NDUFV1 gene, c.640G < A (p.E214K) chr11:67377981 (Exon 1) and c.248C < T (p.S83L) chr11:67376115 (Exon 3) gene. Our case identifies a previously unknown pathogenic effect of the variant ‘c.248C > T’ in the NDUFV1 gene, observed in a 4-year-old boy with left-sided facial paralysis and balance impairment. While this discovery is significant, further exploration of NDUFV1 gene variants is essential for a comprehensive understanding and effective treatment strategies.