congenital lactic acidosis, Saguenay-Lac-Saint-Jean type
Findings
No curated finding names congenital lactic acidosis, Saguenay-Lac-Saint-Jean type yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Saguenay-Lac-St. Jean (SLSJ) type congenital lactic acidosis, a French Canadian form of Leigh syndrome, is a mitochondrial disease characterized by chronic metabolic acidosis, hypotonia, facial dysmorphism and delayed development.
Definition from the Mondo Disease Ontology (MONDO:0009069), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Death in infancy · Congenital onset · Infantile onset · Neonatal onset
HPO, annotations 2026-09-02
Features
88 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.
- Decreased activity of mitochondrial complex IVHPOHP:0008347
- 10 of 10 reported patients
- Very frequent (80% to 99% of cases)
- Increased circulating lactate concentrationHPOHP:0002151
- 10 of 10 reported patients
- Very frequent (80% to 99% of cases)
- Increased CSF lactateHPOHP:0002490
- 3 of 3 reported patients
- Very frequent (80% to 99% of cases)
- Abnormal circulating enzyme concentration or activityHPOHP:0012379
- Very frequent (80% to 99% of cases)
- Failure to thriveHPOHP:0001508
- Very frequent (80% to 99% of cases)
- Global developmental delayHPOHP:0001263
Show the remaining 76
- AtaxiaHPOHP:0001251
- Frequent (30% to 79% of cases)
- ChoreaHPOHP:0002072
- Frequent (30% to 79% of cases)
- Cytochrome C oxidase-negative muscle fibersHPOHP:0003688
- Frequent (30% to 79% of cases)
- Decreased liver functionHPOHP:0001410
- Frequent (30% to 79% of cases)
- Developmental regressionHPOHP:0002376
- Frequent (30% to 79% of cases)
- EEG with abnormally slow frequenciesHPOHP:0011203
- Frequent (30% to 79% of cases)
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.
- LRPPRCHGNC:15714
- Definitive · G2P · Autosomal recessive · 2025
- Definitive · Natera · Autosomal recessive · 2023
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2021
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
7 names
Resolves to: congenital lactic acidosis, Saguenay-Lac-Saint-Jean type
- Also called
- COX deficiency, French-Canadian typecytochrome C oxidase deficiency, French-Canadian typecytochrome oxidase deficiency, Saguenay-Lac-Saint-Jean typeLeigh syndrome, French-Canadian typeLeigh syndrome, Saguenay-Lac-Saint-Jean typemitochondrial complex IV deficiency, nuclear type 5, (French-Canadian)SLSJ-COX deficiency