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Published on: November 5, 2019
Ethylmalonic encephalopathy masquerading as meningococcemia
Ari Horton1,2,3,4, Kai Mun Hong5, Dinusha Pandithan6
1Monash Genetics, Monash Health, Melbourne, Victoria, Australia.
Abstract:
Ethylmalonic encephalopathy (MIM #602473) is a rare autosomal recessive metabolic condition caused by biallelic variants in ETHE1 (MIM #608451), characterized by global developmental delay, infantile hypotonia, seizures, and microvascular damage. The microvascular changes result in a pattern of relapsing spontaneous diffuse petechiae and purpura, positional acrocyanosis, and pedal edema, hemorrhagic suffusions of mucous membranes, and chronic diarrhea. Here, we describe an instructive case in which ethylmalonic encephalopathy masqueraded as meningococcal septicemia and shock. Ultrarapid whole-genome testing (time to result 60 h) and prompt biochemical analysis facilitated accurate diagnosis and counseling with rapid implementation of precision treatment for the metabolic crisis related to this condition. This case provides a timely reminder to consider rare genetic diagnoses when atypical features of more common conditions are present, with an early referral to ensure prompt biochemical and genomic diagnosis.
Insights
Ethylmalonic encephalopathy, a rare genetic disorder, can mimic severe infections. Rapid genomic testing is crucial for early diagnosis and precise treatment of this metabolic crisis.
Area of Science:
- Biochemistry
- Genetics
- Pediatrics
Background:
- Ethylmalonic encephalopathy is a rare autosomal recessive metabolic disorder.
- It is caused by biallelic variants in the ETHE1 gene.
- Clinical features include global developmental delay, hypotonia, seizures, and microvascular damage.
Purpose of the Study:
- To describe a case of ethylmalonic encephalopathy presenting as meningococcal septicemia.
- To highlight the utility of ultrarapid whole-genome testing in diagnosing rare genetic conditions.
- To emphasize the importance of considering genetic diagnoses in atypical presentations.
Main Methods:
- Case report of a patient with ethylmalonic encephalopathy.
- Ultrarapid whole-genome sequencing (60-hour turnaround time).
- Biochemical analysis.
Main Results:
- The patient's presentation mimicked meningococcal septicemia and shock.
- Rapid genomic and biochemical testing enabled accurate diagnosis.
- Precision treatment was initiated promptly for the metabolic crisis.
Conclusions:
- Rare genetic disorders like ethylmalonic encephalopathy can present with atypical features mimicking common conditions.
- Prompt biochemical and genomic diagnosis is essential for effective management.
- Early consideration of genetic diagnoses is critical for patients with unusual symptoms.

