aminolevulinate (ALA) dehydratase deficiency pophyria; porphobilinogen (PBG) synthase deficiency porphyria

Etiology

• almost complete deficiency of a ALA dehydratase
• accumulation of aminolevulinate
• inhibition of heme synthesis

Epidemiology

• rarest from of porphyria (only 4 cases reported)
• onset: adolescence (2 cases), infancy (1 case), age 63 (1 case)

Clinical manifestations

• insufficient data
• that seen is similar to acute intermittent porphyria

Laboratory

• urine
  • markedly elevated aminolevulinate
  • porphobilinogen within normal limits
  • *markedly elevated coproporphyrin III
  • *markedly elevated protoporphyrin IX
• erythrocytes
  • *markedly elevated coproporphyrin III
  • *markedly elevated protoporphyrin IX

* No satisfactory explanation for these findings. Perhaps ferrochelatase affected as well.

Differential diagnosis

• lead poisoning
• hereditary tyrosinemia I

Management

• insufficient data
• treat as for acute intermittent porphyria

More general terms

• porphyria

Additional terms

• acute intermittent porphyria (AIP); Swedish porphyria
• delta-aminolevulinic acid dehydratase; ALADH; porphobilinogen synthase (ALAD)
• heme synthesis