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| ID | Type | Description | Link |
|---|---|---|---|
| 1U54DK083909 | U.S. NIH Grant/Contract | View source |
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| Name | Class |
|---|---|
| University of Texas | OTHER |
| University of Alabama at Birmingham | OTHER |
| Icahn School of Medicine at Mount Sinai | OTHER |
| University of Utah |
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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:
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Group 1 | Group 1 will include subjects 15 years of age or older who are a first-degree relative (child, sibling, parent, or grandparent) of an individual with genetically proven acute porphyria (AIP, HCP or VP), and have not had any previous genetic testing for porphyria themselves. | ||
| Group 2 (Not Yet Enrolling) | Group 2 will consist of subjects 15 years of age or older who have a history of clinical features suggestive of acute porphyria, such as such as abdominal, back or limb pain, recurrent nausea lasting days, reaction to medications, psychiatric history, or sun sensitivity, and an increase in urinary, fecal or serum porphobilinogen (PBG) and/or porphyrins. | ||
| Group 3 | Subjects in Group 3 will participate in the "Follow Up Sub-Study." This group will include individuals who have been seen by one of the Porphyria Consortium physicians/investigators for suspicion of porphyria 10 or more years prior to study initiation, but were not given a diagnosis of porphyria at the time of their initial visit. |
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| Measure | Description | Time Frame |
|---|---|---|
| Presence of positive biochemical features by first-line testing in subjects suspected of being a genetic carrier of acute porphyria | All subjects will be assessed for any elevation of quantitative urine porphobilinogen (PBG). | Assessed once at baseline visit for all subjects |
| Presence of positive biochemical features by second-line testing in subjects suspected of being a genetic carrier of acute porphyria | All subjects will be assessed for any elevations of fractionated quantitative urine porphyrins. | Assessed once at baseline visit for all subjects |
| Presence of positive biochemical features by second-line testing in subjects suspected of being a genetic carrier of acute porphyria | All subjects will be assessed for any elevations and levels of fractionated quantitative fecal porphyrins. | Assessed once at baseline visit for all subjects |
| Clinical features suggestive of the acute porphyria carrier state | Through a focused questionnaire, we will determine the typical duration of pain attacks. | Assessed once at baseline visit for all subjects |
| Acute porphyria genetic carrier state | All subjects will undergo DNA analysis to detect a mutation in the HMBS, CPOX, or PPOX genes, respectively. | Assessed once at baseline visit for all subjects |
| Other possible causes of mildly elevated porphyrins and recurrent pain | Participants in the Follow-up Sub-study section of this protocol will be interviewed concerning other possible causes of mildly elevated porphyins and recurrent pain. These will be patients previously seen by the investigator who were deemed not to have porphyria. |
| Measure | Description | Time Frame |
|---|---|---|
| Frequency of disease manifestations in genetically confirmed AIP and HCP | Subjects who are confirmed to have AIP and HCP will be assessed at annual follow up visits for the presence and frequency of porphyria symptoms. | Assessed annually for 5 years |
| Prevalence of HCP in a population with elevation of urine coproporphyrin and pain symptoms. |
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Group 1 Inclusion Criteria:
Group 2 Inclusion Criteria:
Groups 1 and 2 Exclusion Criteria:
Follow Up Sub-Study (Group 3) Inclusion Criteria:
Follow Up Sub-Study (Group 3) Exclusion Criteria:
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Group 1:
Individuals who are first-degree relatives of a patient with one of the acute porphyrias (AIP, HCP, VP). They will complete questionnaires and laboratory tests, including genetic testing for porphyria. The data will be used to develop a clinical profile for the risk factors associated with the genetic carrier state.
Group 2:
Subjects who possibly have acute porphyria, but do not have a confirmed diagnosis based on genetic testing. They will serve to test the validity of the clinical index derived from Group 1.
Group 3:
Patients who have been seen by one of the Porphyria Consortium physicians/investigators 10 or more years ago, but were not given a diagnosis of porphyria. They will complete a questionnaire to determine whether they received a porphyria diagnosis, or another diagnosis that might explain the initial presentation.
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| Name | Affiliation | Role |
|---|---|---|
| Bruce Wang, M.D. | University of California at San Francisco | Study Chair |
| Karl E. Anderson, M.D. | University of Texas | Principal Investigator |
| Joseph R. Bloomer, M.D. | University of Alabama at Birmingham | Principal Investigator |
| Robert J. Desnick, Ph.D., M.D. | Icahn School of Medicine at Mount Sinai | Principal Investigator |
| James P. Kushner, M.D. | University of Utah | Principal Investigator |
| Herbert L. Bonkovsky, M.D. | Carolinas Medical Center and HealthCare System | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| UAB Porphyria Center, University of Alabama at Birmingham | Birmingham | Alabama | 35294 | United States | ||
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| ID | Term |
|---|---|
| D046349 | Coproporphyria, Hereditary |
| D017118 | Porphyria, Acute Intermittent |
| D046350 | Porphyria, Variegate |
| ID | Term |
|---|---|
| D017094 | Porphyrias, Hepatic |
| D008107 | Liver Diseases |
| D004066 | Digestive System Diseases |
| D012873 | Skin Diseases, Genetic |
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| OTHER |
| Carolinas Medical Center | OTHER |
| National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) | NIH |
| Rare Diseases Clinical Research Network | NETWORK |
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| Assessed once during a one-time telephone or in-person interview |
| Presence of heavy metals | All subjects will undergo a blood test to screen for the presence of heavy metals as a cause for minor elevations of porphyrin levels. | Assessed once at baseline visit for all subjects |
| Validity of Genetic Carrier Profile | The biochemical and clinical features of genetically proven but asymptomatic HCP will be tabulated and compared to subjects who are not genetic carriers. Its accuracy in predicting risk factors for HCP will be tested in subjects in Group 2. | The profile will be tested once during the baseline visit for subjects in Group 2. |
Based on the number of subjects in Group 2 determined by DNA analysis to have HCP, we will approximate the prevalence of HCP in a population with elevations in coproporphyrin and pain symptoms that are undiagnosed. |
| Assessed once enrollment and genetic testing of subjects in Group 2 are complete - after a 1-year recruitment and enrollment period. |
| UCSF Porphyria Center, University of California at San Francisco |
| San Francisco |
| California |
| 94143 |
| United States |
| Mount Sinai Porphyria Comprehensive Diagnostic & Treatment Center, Mount Sinai School of Medicine | New York | New York | 10029 | United States |
| Wake Forest University School of Medicine | Winston-Salem | North Carolina | 27157 | United States |
| UTMB Porphyria Center, University of Texas Medical Branch | Galveston | Texas | 77555 | United States |
| Porphyria Center, University of Utah | Salt Lake City | Utah | 84132 | United States |
| D030342 |
| Genetic Diseases, Inborn |
| D009358 | Congenital, Hereditary, and Neonatal Diseases and Abnormalities |
| D012871 | Skin Diseases |
| D017437 | Skin and Connective Tissue Diseases |
| D011164 | Porphyrias |
| D008659 | Metabolic Diseases |
| D009750 | Nutritional and Metabolic Diseases |