ICD-11 definition : Porphyrias constitute a group of diseases characterized by intermittent neuro-visceral
manifestations, cutaneous lesions or by the combination of both. All porphyrias are
caused by a deficiency in one of the enzymes of the heme biosynthesis pathway resulting
in an accumulation of porphyrins and/or their precursors in the liver or bone marrow.
Clinical signs of the disease usually appear in adulthood, but some porphyrias affect
children. Porphyrias can be classified according to the main location of the metabolic
anomaly. Direct or indirect neurotoxicity may cause neurological manifestations. Transmission
of hereditary porphyrias is autosomal and either dominant with weak penetrance or
recessive with complete penetrance. Diagnosis is mainly based on the measurement of
porphyrins and their precursors in biological samples.;
Porphyrias constitute a group of diseases characterized by intermittent neuro-visceral
manifestations, cutaneous lesions or by the combination of both. All porphyrias are
caused by a deficiency in one of the enzymes of the heme biosynthesis pathway resulting
in an accumulation of porphyrins and/or their precursors in the liver or bone marrow.
Clinical signs of the disease usually appear in adulthood, but some porphyrias affect
children. Porphyrias can be classified according to the main location of the metabolic
anomaly. Direct or indirect neurotoxicity may cause neurological manifestations. Transmission
of hereditary porphyrias is autosomal and either dominant with weak penetrance or
recessive with complete penetrance. Diagnosis is mainly based on the measurement of
porphyrins and their precursors in biological samples.