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Genetics Home Reference: your guide to understanding genetic conditions
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FECH

Reviewed July 2009

What is the official name of the FECH gene?

The official name of this gene is “ferrochelatase.”

FECH is the gene's official symbol. The FECH gene is also known by other names, listed below.

What is the normal function of the FECH gene?

The FECH gene provides instructions for making an enzyme known as ferrochelatase. This enzyme is involved in the production of a molecule called heme. Heme is vital for all of the body's organs, although it is most abundant in the blood, bone marrow, and liver. Heme is an essential component of iron-containing proteins called hemoproteins, including hemoglobin (the protein that carries oxygen in the blood).

The production of heme is a multi-step process that requires eight different enzymes. Ferrochelatase is responsible for the eighth and final step in this process, in which an iron atom is inserted into the center of protoporphyrin IX (the product of the seventh step) to form heme.

How are changes in the FECH gene related to health conditions?

porphyria - caused by mutations in the FECH gene

More than 110 mutations in the FECH gene have been identified in individuals with a form of porphyria called erythropoietic protoporphyria. A mutation in one copy of the FECH gene reduces each cell's production of ferrochelatase by about half. However, this is not enough to cause the signs and symptoms of porphyria; people with this disorder must also inherit a second altered copy of FECH. In some affected individuals, the second copy of the FECH gene is also nonfunctional, and cells make almost no ferrochelatase. In other affected individuals, the second copy of the FECH gene retains some of its function. This version of the gene is described as a low-expression allele. It reduces, but does not eliminate, the amount of ferrochelatase produced within cells. A combination of two mutated copies of the FECH gene in each cell, or one mutated copy of the gene and one low-expression allele, is necessary for erythropoietic protoporphyria to develop.

A shortage of functional ferrochelatase allows compounds called porphyrins to build up in developing red blood cells. These compounds are formed during the normal process of heme production, but reduced activity of ferrochelatase allows them to accumulate to toxic levels. The excess porphyrins can leak out of developing red blood cells and be transported through the bloodstream to the skin and other tissues. High levels of these compounds in the skin cause the oversensitivity to sunlight that is characteristic of this condition. Large amounts of porphyrins in the gallbladder can also cause gallstones. Less commonly, a buildup of these compounds in the liver can result in liver damage.

Where is the FECH gene located?

Cytogenetic Location: 18q21.3

Molecular Location on chromosome 18: base pairs 57,544,840 to 57,586,736

The FECH gene is located on the long (q) arm of chromosome 18 at position 21.3.

The FECH gene is located on the long (q) arm of chromosome 18 at position 21.3.

More precisely, the FECH gene is located from base pair 57,544,840 to base pair 57,586,736 on chromosome 18.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about FECH?

You and your healthcare professional may find the following resources about FECH helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the FECH gene or gene products?

  • Ferrochelatase, mitochondrial
  • ferrochelatase (protoporphyria)
  • Heme Synthetase
  • HEMH_HUMAN
  • Porphyrin-Metal Chelatase
  • Protoheme Ferro-Lyase

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding FECH?

allele ; atom ; bone marrow ; cell ; enzyme ; gallbladder ; gene ; heme ; hemoglobin ; inherit ; iron ; molecule ; mutation ; oxygen ; porphyrin ; protein ; protoheme ; toxic

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Badminton MN, Elder GH. Molecular mechanisms of dominant expression in porphyria. J Inherit Metab Dis. 2005;28(3):277-86. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15868463?dopt=Abstract)
  • Bloomer JR, Wang Y, Singhal A, Risheg H. Biochemical abnormality in erythropoietic protoporphyria: cause and consequences. J Pediatr Gastroenterol Nutr. 2006 Jul;43 Suppl 1:S36-40. (http://www.ncbi.nlm.nih.gov/pubmed/16819399?dopt=Abstract)
  • Di Pierro E, Moriondo V, Cappellini MD. Human gene mutations. Gene symbol: FECH. Disease: Porphyria, erythropoietic. Hum Genet. 2004 Jan;114(2):221. (http://www.ncbi.nlm.nih.gov/pubmed/15046047?dopt=Abstract)
  • Elder GH. Genetic defects in the porphyrias: types and significance. Clin Dermatol. 1998 Mar-Apr;16(2):225-33. Review. (http://www.ncbi.nlm.nih.gov/pubmed/9554235?dopt=Abstract)
  • Gouya L, Martin-Schmitt C, Robreau AM, Austerlitz F, Da Silva V, Brun P, Simonin S, Lyoumi S, Grandchamp B, Beaumont C, Puy H, Deybach JC. Contribution of a common single-nucleotide polymorphism to the genetic predisposition for erythropoietic protoporphyria. Am J Hum Genet. 2006 Jan;78(1):2-14. Epub 2005 Nov 15. (http://www.ncbi.nlm.nih.gov/pubmed/16385445?dopt=Abstract)
  • Gouya L, Puy H, Robreau AM, Bourgeois M, Lamoril J, Da Silva V, Grandchamp B, Deybach JC. The penetrance of dominant erythropoietic protoporphyria is modulated by expression of wildtype FECH. Nat Genet. 2002 Jan;30(1):27-8. Epub 2001 Dec 20. (http://www.ncbi.nlm.nih.gov/pubmed/11753383?dopt=Abstract)
  • Gouya L, Puy H, Robreau AM, Lyoumi S, Lamoril J, Da Silva V, Grandchamp B, Deybach JC. Modulation of penetrance by the wild-type allele in dominantly inherited erythropoietic protoporphyria and acute hepatic porphyrias. Hum Genet. 2004 Feb;114(3):256-62. Epub 2003 Dec 11. (http://www.ncbi.nlm.nih.gov/pubmed/14669009?dopt=Abstract)
  • Herrero C, To-Figueras J, Badenas C, Méndez M, Serrano P, Enríquez-Salamanca R, Lecha M. Clinical, biochemical, and genetic study of 11 patients with erythropoietic protoporphyria including one with homozygous disease. Arch Dermatol. 2007 Sep;143(9):1125-9. (http://www.ncbi.nlm.nih.gov/pubmed/17875872?dopt=Abstract)
  • Kauppinen R. Porphyrias. Lancet. 2005 Jan 15-21;365(9455):241-52. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15652607?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/2235)
  • Rand EB, Bunin N, Cochran W, Ruchelli E, Olthoff KM, Bloomer JR. Sequential liver and bone marrow transplantation for treatment of erythropoietic protoporphyria. Pediatrics. 2006 Dec;118(6):e1896-9. Epub 2006 Oct 30. (http://www.ncbi.nlm.nih.gov/pubmed/17074841?dopt=Abstract)
  • Risheg H, Chen FP, Bloomer JR. Genotypic determinants of phenotype in North American patients with erythropoietic protoporphyria. Mol Genet Metab. 2003 Sep-Oct;80(1-2):196-206. (http://www.ncbi.nlm.nih.gov/pubmed/14567969?dopt=Abstract)
  • Sassa S, Kappas A. Molecular aspects of the inherited porphyrias. J Intern Med. 2000 Feb;247(2):169-78. Review. (http://www.ncbi.nlm.nih.gov/pubmed/10692079?dopt=Abstract)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: July 2009
Published: July 21, 2014