cystathioninuria (Monarch Disease Ontology id MONDO_0009058) is an autosomal recessive disorder caused by cystathionine gamma-lyase deficiency. It is usually pyridoxine-dependent, but in very rare cases it may be non-dependent. It is generally considered to be a benign condition without pathogenic relevance. However, association of cystathioninuria with intellectual impairment has been reported in several cases. Also known as: Cystathione gamma-lyase deficiency syndrome, cystathionase deficiency, cystathione gamma-lyase deficiency syndrome, cystathioninuria (disease), gamma-cystathionase deficiency.