IEMbase 0020: TAT-related tyrosine aminotransferase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 20 |
| Nosology | 1.4.02.01 |
| Gene | TAT |
| External IDs | OMIM:276600 |
| Generated mapping | CANDIDATE by fuzzy alias to Tyrosinemia_Type_I.yaml |
| Candidate DisMech targets | No current standalone target; Tyrosinemia_Type_I.yaml is a false-positive candidate |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents tyrosinemia type II/Richner-Hanhart syndrome. Characteristic clinical features are corneal erosion and palmoplantar hyperkeratosis. Additional features include photophobia, lacrimation, blisters and erosions on palms and soles, and occasional intellectual disability.
The biochemical profile is severe hypertyrosinemia with elevated urinary 4-hydroxyphenylacetic acid, 4-hydroxyphenyllactic acid, and 4-hydroxyphenylpyruvic acid. The listed treatment is phenylalanine and tyrosine restriction.
DisMech phenotype coverage
There is no current standalone DisMech entry for TAT-related tyrosinemia type
II. The generated fuzzy candidate, Tyrosinemia_Type_I.yaml, is not appropriate:
HT1 is FAH-related, dominated by liver failure, renal tubular dysfunction,
succinylacetone, delta-ALA, and hepatocellular carcinoma risk. Those features do
not represent the corneal and palmoplantar phenotype of TAT deficiency.
Concordance and completeness
Judgement: unmapped disease-level gap. The candidate is a tyrosinemia-family string match, not a biological or phenotypic match.
IEMbase contributes a clear compact phenotype set for a future entry: corneal erosions/photophobia/lacrimation, palmoplantar hyperkeratosis with blistering or erosions, intellectual disability as a variable feature, high plasma tyrosine, elevated urinary p-hydroxyphenyl organic acids, and dietary phenylalanine and tyrosine restriction.
Curation actions
- Do not map this record to
Tyrosinemia_Type_I.yaml. - Add a future standalone
Tyrosinemia_Type_IIor TAT-deficiency disease entry if this disease is in scope for curation. - Use this note as a phenotype checklist for that future entry.