You are in: eMedicine Specialties > Hematology > Heme Synthesis and Disorders Porphyria, ChesterArticle Last Updated: Dec 19, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Koyamangalath Krishnan, MD, FRCP, FACP, Dishner Endowed Chair of Excellence in Medicine, Professor of Medicine and Chief of Hematology-Oncology, Program Director, Hematology-Oncology Fellowship, James H Quillen College of Medicine at East Tennessee State University Koyamangalath Krishnan is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians-American Society of Internal Medicine, American Society of Clinical Oncology, American Society of Hematology, and Royal College of Physicians Coauthor(s): Vijay Ramu, MBBS, Staff Physician, Department of Internal Medicine, East Tennessee State University; Harsha Vardhana, MD, Medical Oncology Fellow, Department of Internal Medicine, Division of Hematology/Oncology, James H Quillen College of Medicine at East Tennessee State University Editors: Clarence Sarkodee-Adoo, MD, Consulting Staff, Department of Bone Marrow Transplantation, City of Hope Samaritan BMT Program; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Marcel E Conrad, MD, BS, (Retired) Distinguished Professor of Medicine, University of South Alabama; Rajalaxmi McKenna, MD, FACP, Consulting Staff, Department of Medicine, Southwest Medical Consultants, SC, Good Samaritan Hospital, Advocate Health Systems; Emmanuel C Besa, MD, Professor, Department of Medicine, Division of Hematologic Malignancies, Kimmel Cancer Center, Thomas Jefferson University Author and Editor Disclosure Synonyms and related keywords: Dobson's complaint, heme biosynthesis, enzyme defects, acute intermittent porphyria, AIP, acute porphyria, intermittent acute porphyria, IAP, biochemical defects, variegate porphyria, VP, neurovisceral dysfunction, metabolism error, hypertension, abdominal colic, psychosis, neuropathy, Chester porphyria gene, inborn error of metabolism, porphobilinogen deaminase, protoporphyrinogen oxidase INTRODUCTIONSection 2 of 11
  BackgroundPorphyrias are inborn errors of metabolism in which specific enzyme defects exist in the heme synthesis pathway. Chester porphyria is a unique type of porphyria with the clinical picture of acute intermittent porphyria (AIP) and the biochemical defects of both acute intermittent porphyria and variegate porphyria (VP). The first description of this disease is from a clinical observation made by an anesthetist, Zorka Bekerus, in Chester, England, in 1963 (hence the name Chester porphyria). The index case, Peter Dobson, was a salmon fisherman born in 1867 in Chester. Numerous family members had the condition, and the family coined the term Dobson's complaint to describe the mysterious illness. PathophysiologyChester porphyria does not conform to any of the recognized types of acute porphyria (see Image 1). The urine porphyrin excretory pattern varies from the pattern of acute intermittent porphyria to variegate porphyria. Chester porphyria exhibits reduction in enzymatic activity of both porphobilinogen deaminase (an enzyme with reduced activity in acute intermittent porphyria) and protoporphyrinogen oxidase (an enzyme with reduced activity in variegate porphyria). Chester porphyria manifests with attacks of neurovisceral dysfunction common to all acute porphyrias. Unlike in variegate porphyrias, cutaneous photosensitivity is not a feature of Chester porphyria. FrequencyInternationalFrequency is low, and Chester porphyria is only described in the city of Chester, England. Mortality/Morbidity
SexNo sex predilection exists. CLINICALSection 3 of 11
History
Physical
Causes
DIFFERENTIALSSection 4 of 11
ALA Dehydratase Deficiency Porphyria Diabetic Ketoacidosis Polyarteritis Nodosa Porphyria, Acute Intermittent Porphyria, Hereditary Coproporphyria Toxicity, Arsenic Toxicity, Lead Uremia
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| Media file 1: This schematic diagram of biochemical abnormality shows the sites of enzymatic defects of the various porphyrias on the left side of the diagram and the dual enzyme abnormality of Chester porphyria (deficiency of porphobilinogen deaminase and protoporphyrinogen oxidase) on the right. | |
 | View Full Size Image | Media type: Image |
Article Last Updated: Dec 19, 2006
