3-hydroxy-3-methylglutaryl-CoA synthase deficiency
Findings
No curated finding names 3-hydroxy-3-methylglutaryl-CoA synthase deficiency yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
3-hydroxy-3-methylglutaryl-CoA synthase deficiency (HMG-CoA synthase deficiency) is a rare autosomal recessively inherited disorder of ketone body metabolism, reported in less than 20 patients to date, characterized clinically by episodes of decompensation (often associated with gastroenteritis or fasting) that present with vomiting, lethargy, hepatomegaly, non ketotic hypoglycemia and, in rare cases, coma. Patients are mostly asymptomatic between acute epidodes. HMG-CoA synthase deficiency requires an early diagnosis in order to avoid hypoglycemic crises that can lead to permanent brain damage or death.
Definition from the Mondo Disease Ontology (MONDO:0011614), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset · Juvenile onset · Childhood onset
HPO, annotations 2026-09-02
Features
21 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- DiarrheaHPOHP:0002014
- 1 of 1 reported patient
- Elevated circulating alanine aminotransferase concentrationHPOHP:0031964
- 1 of 1 reported patient
- Elevated circulating aspartate aminotransferase concentrationHPOHP:0031956
- 1 of 1 reported patient
- Hypoglycemic comaHPOHP:0001325
- 1 of 1 reported patient
- HypophosphatemiaHPOHP:0002148
- 3 of 3 reported patients
- Increased circulating free fatty acid levelHPO
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- HMGCS2HGNC:5008
- Definitive · ClinGen · Autosomal recessive · 2018
- Definitive · G2P · Autosomal recessive · 2015
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
2 names
Resolves to: 3-hydroxy-3-methylglutaryl-CoA synthase deficiency
- Also called
- HMG-CoA synthase deficiencyHMG-CoA synthase-2 deficiency