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IEMbase 0139: DPEP1-related Dipeptidase deficiency

Scope

Field Value
IEMbase ID 139
Nosology 2.1.09.01
Gene DPEP1
External IDs OMIM:179780
Generated mapping UNMAPPED
Candidate DisMech targets No valid DPEP1/cystinylglycinuria target found
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as DPEP1-related dipeptidase deficiency, with alternate labels cysteinylglycinuria, cysteinyl-glycinase deficiency, and MBDD. Treatability is marked unknown.

Characteristic biochemical rows include increased cystinylglycine in plasma and urine, increased urinary cysteinylglycine, increased urinary cystine, increased urinary leukotriene D4, and decreased urinary leukotriene E4. RBC glutathione is listed as normal. Clinical rows include partial deafness, abnormal EEG, abnormal EMG, foot deformity, motor impairment, myoclonic seizures, neurocognitive and behavioral issues, and psychomotor delay. No treatment rows are listed.

DisMech phenotype coverage

No local DPEP1, membrane-bound dipeptidase deficiency, or cystinylglycinuria target was found. The local cystinuria entry is not a valid substitute: it models SLC3A1/SLC7A9 amino-acid transporter disease rather than DPEP1 dipeptidase deficiency and leukotriene/cysteinylglycine handling.

Concordance and completeness

Judgement: true unmapped local disease gap.

The IEMbase biochemical signature is specific to cystinylglycine and leukotriene metabolite handling, and the clinical signal is neurodevelopmental/neuromotor. Current DisMech lacks a matching DPEP1 disease entry.

Curation actions

  • Keep this record unmapped.
  • Do not map to cystinuria or other cystine-transporter disease.
  • Future curation should add a DPEP1/cystinylglycinuria target with cystinylglycine/cystine biomarkers, leukotriene D4/E4 imbalance, psychomotor delay, seizures, deafness, and neuromotor findings.