AHP is a rare genetic disease

Acute hepatic porphyria (AHP) refers to a family of rare genetic diseases characterized by potentially life-threatening attacks and, for some people, chronic debilitating symptoms that negatively impact daily functioning and quality of life. There are four types of AHP:

The different types of AHP

Most common
  • Types of acute hepatic porphyria from most common to most rare
  • Acute intermittent porphyria (AIP)
  • Variegate porphyria (VP)
  • Hereditary coproporphyria (HCP)
  • ALAD-deficiency porphyria (ADP)

Extremely rare

The symptoms of AHP often resemble those of other diseases in the gastrointestinal, gynecological, and neurological or neuropsychiatric areas. Severe symptoms can lead to hospitalizations and unnecessary surgeries or procedures. Misdiagnosis is common, and people with AHP can wait years for an accurate and confirmed diagnosis.

Find out more about how AHP works by watching the video below. It takes you inside the body, for a deeper understanding of the disease, its signs and symptoms, and common misdiagnoses.

What AHP Does To The Body

  • In people with a genetic defect for AHP, one of the enzymes in the heme pathway doesn’t work properly
  • Heme is essential to our body and is necessary for our liver to function properly
  • In the liver, the heme pathway is controlled by an enzyme called ALAS1
  • When ALAS1 activity is increased, the enzyme that doesn’t work properly is unable to keep up. This results in the buildup of toxins called aminolevulinic acid (ALA) and porphobilinogen (PBG) in the liver, which are released throughout the body
  • ALA and PBG are harmful to nerve cells and have been associated with the symptoms and attacks of AHP
  • Attacks are associated with widespread dysfunction within the nervous system and a wide array of symptoms that can mimic those of other diseases, making a diagnosis difficult

AHP can affect anyone

  • AHP affects people of all races and ethnicities
  • AHP can affect people of all genders and ages, but most cases are in women between the ages of 15 and 45
  • Approximately 80% of people with AHP are women, while around 20% are men
  • Not everyone who has a genetic mutation for AHP will develop symptoms

Everyone experiences AHP
in a different way

Acute attacks can be life-threatening and can last for days. Acute attacks are not the only sign of AHP—some people with AHP also experience debilitating symptoms daily, even when they are not having attacks. This is part of what makes diagnosis difficult.

ACUTE AHP attacks

Person experiencing severe, unexplained abdominal pain during an acute hepatic porphyria attack

Acute attacks can cause severe problems in many parts of the body, and often require hospitalization.

CHRONIC AHP SYMPTOMS

Person experiencing ongoing pain from acute hepatic porphyria

Chronic symptoms, such as anxiety, nausea, pain, and fatigue can take a serious toll on some people with AHP.

There are simple tests your doctor can perform to help determine if you have AHP

Person diagnosed with acute hepatic porphyria

Recognizing the signs and symptoms

Because the symptoms of AHP can mimic many other diseases, being aware of its many possible symptoms can help your doctor identify the disease as early as possible. Recognizing the symptoms is a crucial first step to understanding the disease and knowing how to reduce the likelihood of attacks.

Severe, unexplained abdominal pain is the most common symptom, occurring in more than 90% of people who experience AHP attacks. People with AHP are likely to also experience at least one of many other, seemingly unrelated symptoms.

Signs and Symptoms of AHP

While most people with AHP experience severe abdominal pain during attacks, symptoms vary from person to person and change over time. Not every person with AHP will experience all the symptoms listed here, and some will experience symptoms more frequently or more severe than others.

1CENTRAL
NERVOUS SYSTEM

Confusion
Anxiety
Seizures
Insomnia
Hallucinations
Depression

2PERIPHERAL
NERVOUS SYSTEM

Limb weakness or pain
Numbness
Fatigue
Tiredness
Paralysis
Respiratory paralysis
Sensory loss

3CARDIOVASCULAR

Rapid heart rate
High blood pressure

signs and symptoms diagram

4CUTANEOUS (SKIN) SYMPTOMS*

Lesions or blisters on sun-exposed skin

5GASTROINTESTINAL

Constipation or diarrhea

6AUTONOMIC
NERVOUS SYSTEM

Unexplained abdominal pain
Pain in back or chest
Nausea and vomiting

Other

Dark or reddish urine
Low blood sodium

*Hereditary coproporphyria and variegate porphyria primarily.

There are a number of triggers for AHP attacks

Common triggers are shown below. Since triggers can be different for every person, there may be others not listed here.

Certain medications as a trigger

SOME MEDICATIONS

Hormones as triggers

Hormones including levels of estrogen and progesterone. These hormones fluctuate the most during the 2 weeks before a woman’s menstrual cycle begins

Alcohol consumption as a trigger

ALCOHOL

Smoking as a trigger

SMOKING

Stress induced triggers

Stress
caused by:

−Infections
−Surgery
−Physical
exhaustion
−Emotional
exhaustion
Fasting as a trigger

Fasting or extreme dieting

AHP can be misdiagnosed as other conditions

The signs and symptoms of AHP can be mistaken for those of other conditions, shown below. These misdiagnoses can lead to unnecessary treatments, surgeries, and hospital stays.

Gastrointestinal misdiagnoses

Gastrointestinal disorders

  • Irritable bowel syndrome (IBS)
  • Acute gastroenteritis with vomiting
  • Hepatitis
Neurological or neuropsychiatric misdiagnoses

Neurological/neuropsychiatric disorders

  • Fibromyalgia
  • Guillain-Barré syndrome
  • Psychosis
 
Gynecological misdiagnoses

Gynecological disorder

  • Endometriosis
Abdominal conditions as misdiagnoses

Abdominal conditions requiring surgery

  • Appendicitis
  • Cholecystitis
  • Peritonitis
  • Intestinal occlusion

Learn How Doctors Test for AHP

SIGN UP to receive updated information about AHP from Alnylam.

All fields are required.

 

Thank you for connecting with us.

One step away! You will receive an email shortly to verify your information and complete enrollment for AHP updates for Alnylam.

Patient - Branded Modal Block