hypermethioninemia with deficiency of S-adenosylhomocysteine hydrolase
Findings
No curated finding names hypermethioninemia with deficiency of S-adenosylhomocysteine hydrolase yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Psychomotor retardation due to S-adenosylhomocysteine hydrolase deficiency is characterized by psychomotor delay and severe myopathy (hypotonia, absent tendon reflexes and delayed myelination) from birth, associated with hypermethioninaemia and elevated serum creatine kinase levels.
Definition from the Mondo Disease Ontology (MONDO:0013404), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset
HPO, annotations 2026-09-02
Features
52 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 hepatic echogenicityHPOHP:0031143
- 1 of 1 reported patient
- Decreased tissue S-adenosylhomocysteine hydrolase activityHPOHP:6000750
- 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
- Elevated circulating creatine kinase MM isoform concentrationHPOHP:0032234
- 1 of 1 reported patient
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.
- AHCYHGNC:343
- Definitive · ClinGen · Autosomal recessive · 2024
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Strong · PanelApp Australia · Autosomal recessive · 2025
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
- A kind of