CBS
Chr 21ARcystathionine beta-synthase
The encoded protein functions as a homotetramer that catalyzes the conversion of homocysteine to cystathionine in the transsulfuration pathway, using pyridoxal phosphate as a cofactor and activated by adenosyl-methionine. Mutations cause autosomal recessive cystathionine beta-synthase deficiency leading to homocystinuria (both B6-responsive and nonresponsive types) and hyperhomocysteinemic thrombosis. The pathogenic mechanism involves loss of enzymatic function resulting in toxic accumulation of homocysteine.
Definitive — sufficient evidence for diagnostic panels
Some data sources returned errors (1)
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Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Mild missense constraint
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
CBS · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
The CurePSP Genetics Program
RECRUITINGTargeted Precision Nutrition Strategy To Prevent Chronic Metabolic Diseases
RECRUITINGEarly Severe Illness TrAnslational BioLogy InformaticS in Humans
RECRUITINGAmyotrophic Lateral Sclerosis (ALS) Families Project
RECRUITINGThe NADAPT Study: a Randomized Double-blind Trial of NAD Replenishment Therapy for Atypical Parkinsonism
RECRUITINGPersonalized Antisense Oligonucleotide Therapy for A Single Patient With CHCHD10 ALS (nL18576)
NOT YET RECRUITINGEffects of Probiotics in Amyotrophic Lateral Sclerosis-Frontotemporal Dementia Spectrum Disorder (ALS-FTDSD) Patients
RECRUITINGTracking and Predicting How Brain Damage Spreads in Neurodegenerative Diseases
ENROLLING BY INVITATIONExternal Resources
Links to major genomics databases and tools