Disease Directory Acute Intermittent Porphyria
Metabolic

Acute Intermittent Porphyria

Also known as: AIP, HMBS deficiency, porphobilinogen deaminase deficiency, Swedish porphyria

Prevalence

1-5 per 10,000 (Orphanet)

Onset

Adolescent, Adult

Type

Autosomal dominant genetic

Gene

HMBS

About Acute Intermittent Porphyria

Acute intermittent porphyria (AIP) is the most common acute hepatic porphyria, caused by mutations in the HMBS gene encoding hydroxymethylbilane synthase, resulting in haem biosynthesis dysfunction. Patients experience attacks of severe abdominal pain, neurological dysfunction, and autonomic instability triggered by factors including certain drugs, fasting, hormonal changes, and stress. Givosiran (Givlaari), an RNA interference therapy targeting ALAS1, is approved for recurrent attacks.

Common Clinical Features

Severe abdominal pain Peripheral neuropathy Autonomic dysfunction Dark red/brown urine Hyponatremia Seizures Psychiatric symptoms

Clinical Trial Eligibility Tips

What to know before applying to Acute Intermittent Porphyria trials.

Attack frequency in the prior 12 months (typically 2 or more) is the standard inclusion criterion for acute porphyria trials

Urinary aminolevulinic acid (ALA) and porphobilinogen (PBG) levels are required biomarkers — collect during both attacks and between attacks

Givosiran (Givlaari) is approved — trials may study alternative RNAi therapies, hemin formulations, or combination approaches

Drug interaction lists are critical — many common medications are porphyrinogenic and must be reviewed with trial coordinators

Patient Resources

Patient Organization

American Porphyria Foundation

Visit website ↗

Natural History Registry

Porphyrias Consortium Registry

Join registry ↗

Orphanet

European reference resource for rare diseases (ORPHA:79276)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

Search NORD ↗

Find recruiting Acute Intermittent Porphyria trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Acute Intermittent Porphyria. Updated daily.

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