Ethylmalonic encephalopathy-report of two cases

Area of Science:

• Biochemistry
• Genetics
• Pediatric Neurology

Background:

• Ethylmalonic encephalopathy is a rare, autosomal recessive metabolic disorder.
• It presents in infancy with developmental delay, acrocyanosis, petechiae, chronic diarrhea, and often early death.
• Biochemical hallmarks include urinary organic acid abnormalities and are linked to mutations in the ETHE1 gene.

Observation:

• Two additional cases of ethylmalonic encephalopathy are presented.
• The first patient exhibited typical symptoms, atypical clinical features, and extensive neuroimaging changes.
• The second patient presented with typical clinical and biochemical profiles, alongside cytochrome C oxidase deficiency.

Findings:

• A novel homozygous mutation in exon 3 of the ETHE1 gene was identified in the first patient.
• The genetic basis of the second patient was not investigated but clinical and biochemical findings were consistent.
• These cases expand the known spectrum of ETHE1 gene mutations and clinical presentations.

Implications:

• Understanding ETHE1 gene mutations is crucial for diagnosing ethylmalonic encephalopathy.
• The findings contribute to the limited knowledge of this rare metabolic disease.
• Further research may elucidate genotype-phenotype correlations and potential therapeutic targets.