classic homocystinuria
Findings
No curated finding names classic homocystinuria yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Classical homocystinuria due to cystathionine beta-synthase (CbS) deficiency is characterized by the multiple involvement of the eye, skeleton, central nervous system, and vascular system.
Definition from the Mondo Disease Ontology (MONDO:0009352), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Juvenile onset · Neonatal onset · Childhood onset
HPO, annotations 2026-09-02
Features
74 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.
- AtaxiaHPOHP:0001251
- 3 of 3 reported patients
- Brain atrophyHPOHP:0012444
- 3 of 3 reported patients
- Disproportionate tall statureHPOHP:0001519
- 11 of 11 reported patients
- Very frequent (80% to 99% of cases)
- DysarthriaHPOHP:0001260
- 3 of 3 reported patients
- ExotropiaHPOHP:0000577
- 3 of 3 reported patients
- FlushingHPOHP:0031284
- 3 of 3 reported patients
- HyperhomocystinemiaHPO
Show the remaining 62
- Dental crowdingHPOHP:0000678
- Very frequent (80% to 99% of cases)
- Ectopia lentisHPOHP:0001083
- 18 of 37 reported patients
- Very frequent (80% to 99% of cases)
- OsteoporosisHPOHP:0000939
- 0 of 1 reported patient
- Very frequent (80% to 99% of cases)
- Recurrent fracturesHPOHP:0002757
- Very frequent (80% to 99% of cases)
- Lens subluxationHPOHP:0001132
- 13 of 19 reported patients
- Frequent (30% to 79% of cases)
- KyphoscoliosisHPOHP:0002751
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.
- CBSHGNC:1550
- Definitive · ClinGen · Autosomal recessive · 2019
- Definitive · Myriad Women's Health · Autosomal recessive · 2019
- Definitive · G2P · Autosomal recessive · 2017
- Definitive · Natera · Autosomal recessive · 2022
- Strong · Genomics England PanelApp · Autosomal recessive · 2020
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Supportive · Orphanet · Autosomal recessive · 2021
Where it sits
Other names
4 names
Resolves to: classic homocystinuria
- Also called
- cystathionine beta-synthase deficiencyHomocystinuria due to Cystathionine Beta-Synthase Deficiencyhomocystinuria, B6-responsive and nonresponsive typesthrombosis, hyperhomocysteinemic