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IEMbase 0476: KHK-related hepatic fructokinase deficiency

Scope

Field Value
IEMbase ID 476
Nosology 3.1.01.01
Gene KHK
External IDs OMIM:229800; ORPHA:2056
Generated mapping UNMAPPED; low candidate Essential_Thrombocythemia.yaml
Candidate DisMech targets No exact local target
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents autosomal recessive KHK-related hepatic fructokinase deficiency, also called essential fructosuria or ketohexokinase deficiency. Biochemical rows include decreased hepatic ketohexokinase activity, normal urine glucose, and positive urine reducing substances. The characteristic clinical row states "no clinical significance" across age ranges. There are no treatment rows.

DisMech phenotype coverage

There is no exact local DisMech target for KHK-related essential fructosuria. Hereditary_Fructose_Intolerance.yaml mentions ketohexokinase inhibition as an experimental treatment strategy for ALDOB-related HFI, but that is therapeutic KHK inhibition in a different disease, not inherited KHK deficiency.

The generated Essential_Thrombocythemia.yaml candidate is a false positive. Local essential thrombocythemia is a clonal myeloproliferative neoplasm with JAK2/CALR/MPL signaling, thrombocytosis, thrombosis, and bleeding risk. It is unrelated to benign fructose-metabolism fructosuria.

Concordance and completeness

Judgement: true KHK essential fructosuria local gap or possible low-priority scope-review item; reject essential thrombocythemia as an exact mapping.

The IEMbase record is clinically sparse and explicitly marks no clinical significance, but it is mechanistically distinct from ALDOB hereditary fructose intolerance and should not be folded into HFI without a deliberate lumping decision.

Curation actions

  • Keep this record unmapped until a KHK essential fructosuria target exists, or until DisMech makes an explicit out-of-scope decision for clinically benign biochemical traits.
  • Do not map to Essential_Thrombocythemia.yaml.
  • Do not map to Hereditary_Fructose_Intolerance.yaml; KHK inhibition is only contextual there.
  • If curated, include KHK, autosomal recessive inheritance, decreased hepatic ketohexokinase activity, positive urine reducing substances, normal urine glucose, essential fructosuria, and the clinically benign/no-significance characterization.