Porphyrias

Porphyrias are a group of rare metabolic disorders caused by genetic or acquired deficiencies of specific enzymes in the heme biosynthesis pathway. Heme is essential for the formation of hemoglobin, myoglobin, and several other biochemical compounds. As a result of these enzyme defects, toxic intermediate metabolites (porphyrins or their precursors) accumulate in the blood and tissues.

Porphyrias are classified based on the defective enzyme and predominant clinical features. They are generally divided into acute (abdominal) and cutaneous forms.

Clinical manifestations:

Acute (abdominal) porphyrias: Severe abdominal pain without obvious organic cause, painful urination, muscle weakness, neurological symptoms (up to severe paralysis), fatigue, tachycardia, hypertension, psychiatric disturbances (personality changes, aggression, or depression).

Cutaneous porphyrias: Increased skin sensitivity to sunlight, blistering, pigmentation changes, scarring, hypertrichosis (increased facial hair), and dark-colored urine.

Diagnostic methods:

Measurement of porphobilinogen (PBG) and δ-aminolevulinic acid (ALA) in urine.

Spectrophotometric and fluorescent analysis of plasma or urinary porphyrins.

Genetic testing (especially in hereditary forms).