Porphyrias: Classification

Porphyrias can be classified according to various criteria, although there may be overlap. For example, in the context of symptomatology and therapy, acute forms are distinguished from cutaneous forms, although they are differentiated according to different aspects.

According to the cause, a distinction is made between primary and secondary porphyrias:

Primary porphyrias

  • Acute intermittent porphyria (AIP) – ICD-10 E80.2: Other porphyria; autosomal dominant.
  • Porphyria variegata (PV) – ICD-10 E80.2: Other porphyria; autosomal dominant.
  • Hereditary coproporphyria (HCP) – ICD-10 E80.2: Other porphyria; autosomal dominant.
  • Doss porphyria (δ-ALA-deficiency porphyria/ALAD-deficiency porphyria) – ICD-10 E80.2: Other porphyria; autosomal recessive.
  • Porphyria cutanea tarda (PCT) – ICD-10 E80.1; most common form; autosomal dominant or acquired
    • Subform: hepatoerythropoietic porphyria (HEP) – ICD-10 E80.2: other porphyria; autosomal recessive; severe progressive form
  • Congenital erythropoietic porphyria (CEP) (synonym: Günther’s disease) – ICD-10 E80.0: Hereditary erythropoietic porphyria; autosomal recessive.
  • Erythropoietic porphyria (EPP) – ICD-10 E80.0: Hereditary erythropoietic porphyria; autosomal dominant.

Secondary porphyrias

  • Coproporphyrias (acquired)
  • Protoporphyrinemias (acquired)

The porphyrias can be divided into the following two groups depending on where the porphyrins mainly accumulate:

  • Hepatic porphyrias (common) – the porphyrins accumulate mainly in the liver.
    • Porphyria cutanea tarda (PCT).
      • Subtype: hepatoerythropoietic porphyria (HEP).
    • Acute intermittent porphyria (AIP).
    • Porphyria variegata (PV)
    • Hereditary coproporphyria (HCP)
    • Doss porphyria (δ-ALA-deficiency porphyria/ALAD-deficiency porphyria).
  • Erythropoietic porphyrias (rare) – porphyrins accumulate mainly in the bone marrow
    • Erythropoietic porphyria (EPP).
    • Congenital erythropoietic porphyria (CEP) (synonym: Günther’s disease).

Another possible classification of porphyrias can be based on the temporal manifestation of the disease:

Acute porphyrias

  • Acute intermittent porphyria (AIP).
  • Hereditary coproporphyria (HCP).
  • Doss porphyria (δ-ALA-deficiency porphyria/ALAD-deficiency porphyria).
  • Porphyria variegata (PV)

Non-acute porphyria

  • Erythropoietic porphyria (EPP)
  • Congenital erythropoietic porphyria (CEP).
  • Porphyria cutanea tarda (PCT)

Ultimately, porphyrias can be classified according to the presence of manifestations on the skin as follows:

Cutaneous porphyrias

  • Erythropoietic porphyria (EPP).
  • Hereditary coproporphyria (HCP).
  • Congenital erythropoietic porphyria (CEP).
  • Porphyria cutanea tarda (PCT)
  • Porphyria variegata (PV)

Non-cutaneous porphyrias

  • Acute intermittent porphyria (AIP).
  • Doss porphyria (δ-ALA-deficiency porphyria/ALAD-deficiency porphyria).