familial hypertryptophanemia
Findings
No curated finding names familial hypertryptophanemia yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Familial hypertryptophanemia is characterized by intellectual deficit associated with behavioral problems: periodic mood swings, exaggerated affective responses and abnormal sexual behavior. Twelve cases have been reported so far. Congenital abnormalities in tryptophan metabolism appear to be responsible for the tryptophanemia and tryptophanuria.
Definition from the Mondo Disease Ontology (MONDO:0010907), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Neonatal onset
HPO, annotations 2026-09-02
Features
5 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.
- HypertryptophanemiaHPOHP:0500134
- 1 of 1 reported patient · Neonatal onset
- Very frequent (80% to 99% of cases)
- Increased serum serotoninHPOHP:0003144
- 1 of 1 reported patient
- Very frequent (80% to 99% of cases)
- TryptophanuriaHPOHP:0003361
- Very frequent (80% to 99% of cases)
- Global developmental delayHPOHP:0001263
- 0 of 1 reported patient
- Intellectual disabilityHPOHP:0001249
- 0 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.
- TDO2HGNC:11708
- Supportive · Orphanet · Autosomal recessive · 2021
- Limited · ClinGen · Autosomal recessive · 2023
- Limited · Labcorp Genetics (formerly Invitae) · Unknown · 2018
- Limited · PanelApp Australia · Autosomal recessive · 2025