Clinical Diagnosis of Acute Porphyria

Clinical Diagnosis of Acute Porphyria

The purpose of this study is to test whether a focused questionnaire and laboratory tests can better define risk factors associated with possible genetic porphyria. The investigators hypothesize that the genetic carrier state of acute porphyria is distinctive enough that the Genetic Carrier Profile the investigators devise through this study will be useful in identifying carriers of genetic porphyria among the large population with undiagnosed abdominal pain.

The porphyrias are a group of genetic diseases caused by disturbances in the formation of heme, an essential component of hemoglobin and other proteins, leading to either acute (neurologic) and/or chronic (cutaneous) symptoms. Acute porphyria is often difficult to diagnose because symptoms may not be specific and, unless the patient is in an active attack, laboratory values typically may not be useful for diagnosing porphyria. The purpose of this study is to test whether a focused questionnaire and laboratory evaluation tool can better define risk factors associated with possible genetic porphyria. The goals of this study are:

• To determine the presence and number of abnormal lab tests and porphyria-like symptoms in adult family members of the first person in a family who has been diagnosed with a disease of acute porphyria, 50% of whom are expected to carry the same genetic defect of the index case.
• To devise a Genetic Carrie Profile that could be used to screen people in whom the diagnosis of porphyria is being considered.
• To test the Profile in patients with symptoms suggestive of HCP and/or urine tests showing some elevation of porphyrins.
• To explain other possible causes of minor increases in porphyrin levels in patients with recurrent abdominal pain who have not been diagnosed with porphyria

Group 1 Inclusion Criteria:

• Be 15 years of age or older
• Be a first-degree relative (child, sibling, parent, or grandparent) of an individual with genetically proven acute porphyria (AIP, HCP or VP)
• Not have had any previous genetic testing for acute porphyria

Group 2 Inclusion Criteria:

• Be 15 years of age or older
• Have a history of suggestive clinical features, such as abdominal, back or limb pain, recurrent nausea lasting days, reaction to medications, psychiatric history, or sun sensitivity.
• An increase in urinary, fecal or serum porphobilinogen (PBG) and/or porphyrins

Groups 1 and 2 Exclusion Criteria:

• Have previously had genetic testing for acute porphyria
• Have a history of "alarm" symptoms, such as anemia, unintentional weight loss, signs of GI (gastrointestinal) bleeding, or dysphagia (difficulty in swallowing).

Follow Up Sub-Study (Group 3) Inclusion Criteria:

• Have been seen by one of the Porphyria Consortium physicians/investigators 10 or more years prior to study initiation
• Had a slight increase in porphyrins during the initial visit
• Not given a diagnosis of porphyria at the time of the visit

Follow Up Sub-Study (Group 3) Exclusion Criteria:

• You have been seen by the Porphyria Consortium physician/investigator less than 10 years prior to study initiation.