Published online Aug 26, 2022. doi: 10.12998/wjcc.v10.i24.8749
Peer-review started: March 25, 2022
First decision: June 27, 2022
Revised: July 2, 2022
Accepted: July 20, 2022
Article in press: July 20, 2022
Published online: August 26, 2022
Processing time: 143 Days and 18.7 Hours
The mitochondrial respiratory chain defects have become the most common cause of neurometabolic disorders in children and adults, which can occur at any time in life, often associated with neurological dysfunction, and lead to chronic disability and premature death. Approximately one-third of patients with mitochondrial disease have biochemical defects involving multiple respiratory chain complexes, suggesting defects in protein synthesis within the mitochondria. We here report a child with VARS2 gene mutations causing mitochondrial disease.
A girl, aged 3 years and 4 mo, had been unable to sit and crawl alone since birth, with obvious seizures and microcephaly. Brain magnetic resonance imaging showed symmetrical, flaky, long T1-weighted and low T2-weighted signals in the posterior part of the bilateral putamen with a high signal shadow. T2 fluid-attenuated inversion recovery imaging showed a slightly high signal and diffusion-weighted imaging showed an obvious high signal. Whole-exome gene sequencing revealed a compound heterozygous mutation in the VARS2 gene, c.1163(exon11)C>T and c.1940(exon20)C>T, which was derived from the parents. The child was diagnosed with combined oxidative phosphorylation deficiency type 20.
In this patient, mitochondrial disorders including Leigh syndrome and MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) were ruled out, and combined oxidative phosphorylation deficiency type 20 was diagnosed, expanding the phenotypic spectrum of the disease.
Core Tip: The clinical manifestation of the child was remarkable. Through the comprehensive analysis of symptoms, physical examination, biochemical examination and gene sequencing, the child was confirmed to have combined oxidative phosphorylation deficiency type 20, and the phenotypic spectrum of the disease was thus expanded.