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of or relating to the formation of red blood cells
a genetic abnormality of metabolism causing abdominal pains and mental confusion

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/12/13 12:15:12」(JST)

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Erythropoietic porphyria is a type of porphyria associated with erythropoietic cells. In erythropoietic porphyrias, the enzyme deficiency occurs in the red blood cells.^[1]

There are three types:^[2]

Name	OMIM	Gene
erythropoietic protoporphyria (EPP)	177000	ferrochelatase
congenital erythropoietic porphyria or "Gunther's" (CEP)^[3]^:526	263700	uroporphyrinogen III synthase
hepatoerythropoietic porphyria	176100	uroporphyrinogen III decarboxylase

X-linked sideroblastic anemia or "X-linked dominant erythropoietic protoporphyria", associated with ALAS2 (aminolevulinic acid synthase), has also been described. X-linked dominant erythropoietic protoporphyria (XDEPP) is caused by a gain of function mutation in the ALAS2 (5-aminolevulinate synthase) gene; the very first enzyme in the Heme biosynthetic pathway. The mutation is caused by a frameshift mutation caused by one of two deletions in the ALAS2 exon 11, either c. 1706-1709 delAGTG or c. 1699-1700 delAT. This alters the 19th and 20th residues of the C-terminal domain thereby altering the 2° structure of the enzyme. The delAT mutation only occurred in one family studied whereas the delAGTG mutation occurred in several genetically distinct families. The delAGTG causes a loss of an a-helix which is replaced by a ß-sheet.

Previously known mutations in the ALAS2 resulted in a loss-of-function mutation causing X-linked sideroblastic anemia. Erythropoietic protoporphyria (EPP) has similar symptoms as X-linked dominant erythropoietic protoporphyria but the mutation occurs as a loss-of-function in the FECH (ferrochelatase ) enzyme; the very last enzyme in the pathway. All individuals studied presented symptoms without mutations in the FECH enzyme. The patterns of inheritance led the researchers to conclude the mutation must come from an enzyme on the X-chromosome with ALAS2 being the most likely candidate.

X-linked dominant erythropoietic protoporphyria is distinct from EPP in that there is no overload of Fe2+ ions. Additionally, unlike the other the other condition the arises out of a mutation of the ALAS2 gene, there is no anemia. XDEPP is characterized by a build up of Protoporphyrin IX caused by in increased level of function in the ALAS2 enzyme. Because there is a build up of Proporphyrin IX with no malfunction of the FECH enzyme, all the available Fe2+ is used in the production of Heme causing the FECH enzyme to use Zn2+ in its place causing a build up of Zinc Protoporphyrin IX.

X-linked dominant erythropoietic protoporphyria is a relatively mild version of porphyria with the predominate symptom being extreme photo sensitivity causing severe itching and burning of the skin due to the buildup of Protoporphyrin IX. One possible treatment was discovered when treating an individual with supplemental Iron for a gastric ulcer. Levels of free Protoporphyrin decreased significantly as there was iron available for the FECH to produce Heme. Levels of Zn Protoporphyrin, however did not decrease. ^[4]^[5]

References

^ "OMIM - PORPHYRIA, CONGENITAL ERYTHROPOIETIC". http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=263700. Retrieved 2008-12-04.
^ Richard E, Robert-Richard E, Ged C, Moreau-Gaudry F, de Verneuil H (June 2008). "Erythropoietic porphyrias: animal models and update in gene-based therapies". Curr Gene Ther 8 (3): 176–86. doi:10.2174/156652308784746477. PMID 18537592.
^ James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
^ Whatley SD, Ducamp S, Gouya L, et al. (September 2008). "C-terminal deletions in the ALAS2 gene lead to gain of function and cause X-linked dominant protoporphyria without anemia or iron overload". Am. J. Hum. Genet. 83 (3): 408–14. doi:10.1016/j.ajhg.2008.08.003. PMC 2556430. PMID 18760763. http://linkinghub.elsevier.com/retrieve/pii/S0002-9297(08)00441-2.
^ Online 'Mendelian Inheritance in Man' (OMIM) 300752

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1. ポルフィリン症：概要 porphyrias an overview
2. 先天性骨髄性ポルフィリン症 congenital erythropoietic porphyria
3. 骨髄性プロトポルフィリン症およびX連鎖優性プロトポルフィリン症 erythropoietic protoporphyria and x linked protoporphyria
4. 晩発性皮膚ポルフィリン症および肝骨髄性ポルフィリン症：マネージメントおよび予後 porphyria cutanea tarda and hepatoerythropoietic porphyria management and prognosis
5. 晩発性皮膚ポルフィリン症および肝骨髄性ポルフィリン症：臨床的特徴および診断 porphyria cutanea tarda and hepatoerythropoietic porphyria clinical manifestations and diagnosis

English Journal

A molecular study of congenital erythropoietic porphyria in cattle.

Agerholm JS, Thulstrup PW, Bjerrum MJ, Bendixen C, Jørgensen CB, Fredholm M.SourceDepartment of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, Dyrlaegevej 68, DK-1870 Frederiksberg C, Denmark Department of Basic Sciences and Environment, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus Blichers Allé, DK-8830 Tjele, Denmark Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of Copenhagen, Groennegaardsvej 3, DK-1870 Frederiksberg C, Denmark.
Animal genetics.Anim Genet.2012 Apr;43(2):210-215. doi: 10.1111/j.1365-2052.2011.02228.x. Epub 2011 Jul 21.
Previous studies have shown that congenital erythropoietic porphyria (CEP) in cattle is caused by an inherited deficiency of the enzyme uroporphyrinogen III synthase (UROS) encoded by the UROS gene. In this study, we have established the pedigree of an extended Holstein family in which the disease i
PMID 22404357

Japanese Journal

日本の遺伝性ポルフィリン症 : 1920年(第1例報告)から91年間(2010年)の集計

近藤雅雄,矢野雄三,浦田郡平
ALA-porphyrin science 1(2), 73-82, 2012
NAID 40019685103

Congenital erythropoietic porphyria : anesthetic implications

KUMAR MRITUNJAY,BOSE SOMNATH,DARLONG VANLAL,PUNJ JYOTSNA
Journal of anesthesia 23(4), 569-571, 2009-11-20
NAID 10027265119

ポルフィリン症患者およびその未発症血縁者における酸化的ストレスに関する研究

網中雅仁,近藤雅雄,高田礼子 [他],山内博,池田真紀,吉田勝美
日本衞生學雜誌 63(3), 628-635, 2008-05-15
… We sought to establish a causal relationship between oxidative stress and porphyria in patients and carriers. … Methods: We measured urinary 8-hydroxy-2′-deoxyguanosine concentration in porphyria patients and carriers with multifactorial inheritance as a possible marker of attack. …
NAID 10024477788