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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®

Corticosterone methyloxidase deficiency

Reviewed November 2013

What is corticosterone methyloxidase deficiency?

Corticosterone methyloxidase deficiency, also known as aldosterone synthase deficiency, is a disorder characterized by excessive amounts of sodium released in the urine (salt wasting), along with insufficient release of potassium in the urine, usually beginning in the first few weeks of life. This imbalance leads to low levels of sodium and high levels of potassium in the blood (hyponatremia and hyperkalemia, respectively). Individuals with corticosterone methyloxidase deficiency can also have high levels of acid in the blood (metabolic acidosis).

The hyponatremia, hyperkalemia, and metabolic acidosis associated with corticosterone methyloxidase deficiency can cause nausea, vomiting, dehydration, low blood pressure, extreme tiredness (fatigue), and muscle weakness. Affected infants often experience failure to thrive, which means they do not gain weight and grow at the expected rate. Severe cases of corticosterone methyloxidase deficiency can result in seizures and coma and can be life-threatening. However, affected individuals who survive infancy generally have a normal life expectancy, and the signs and symptoms of the disorder typically become milder or disappear by adulthood.

How common is corticosterone methyloxidase deficiency?

Corticosterone methyloxidase deficiency is a rare disorder; its prevalence is unknown. Researchers have described two types of the condition: Type I is more common in the Amish population of Lancaster, Pennsylvania, while type II is more common in people of Iranian Jewish ancestry. The two types have similar signs and symptoms but can be distinguished by laboratory testing.

What genes are related to corticosterone methyloxidase deficiency?

Mutations in the CYP11B2 gene cause corticosterone methyloxidase deficiency. This gene provides instructions for making an enzyme called aldosterone synthase. The aldosterone synthase enzyme is found in the adrenal glands, which are located on top of the kidneys.

Aldosterone synthase helps produce a hormone called aldosterone. Aldosterone regulates blood pressure by maintaining proper salt and fluid levels in the body. The aldosterone synthase enzyme is involved in a series of three chemical reactions that produce aldosterone from other (precursor) molecules: the conversion of 11-deoxycorticosterone to corticosterone, the conversion of corticosterone to 18-hydroxycorticosterone, and the conversion of 18-hydroxycorticosterone to aldosterone.

The CYP11B2 gene mutations that cause corticosterone methyloxidase deficiency lead to insufficient production of aldosterone, which impairs the kidneys' ability to reabsorb salt (sodium chloride or NaCl) into the blood and release potassium in the urine. As a result, excessive amounts of salt in the form of charged atoms (ions) of sodium (Na+) and chlorine (Cl-) leave the body in the urine, while not enough potassium is released. The resulting imbalance of ions in the body underlies the signs and symptoms of corticosterone methyloxidase deficiency.

Related Gene(s)

Changes in this gene are associated with corticosterone methyloxidase deficiency.

  • CYP11B2

How do people inherit corticosterone methyloxidase deficiency?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of corticosterone methyloxidase deficiency?

These resources address the diagnosis or management of corticosterone methyloxidase deficiency and may include treatment providers.

  • MedlinePlus Encyclopedia: Aldosterone (
  • MedlinePlus Encyclopedia: Potassium Test (

You might also find information on the diagnosis or management of corticosterone methyloxidase deficiency in Educational resources and Patient support.

General information about the diagnosis ( and management ( of genetic conditions is available in the Handbook.

To locate a healthcare provider, see How can I find a genetics professional in my area? ( in the Handbook.

Where can I find additional information about corticosterone methyloxidase deficiency?

You may find the following resources about corticosterone methyloxidase deficiency helpful. These materials are written for the general public.

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

What other names do people use for corticosterone methyloxidase deficiency?

  • 18-hydroxylase deficiency
  • 18-oxidase deficiency
  • aldosterone deficiency
  • aldosterone deficiency due to deficiency of steroid 18-hydroxylase
  • aldosterone deficiency due to deficiency of steroid 18-oxidase
  • aldosterone synthase deficiency
  • CMO deficiency
  • congenital hypoaldosteronism
  • corticosterone 18-monooxygenase deficiency
  • corticosterone methyl oxidase deficiency
  • familial hyperreninemic hypoaldosteronism
  • steroid 18-hydroxylase deficiency
  • steroid 18-oxidase deficiency
  • Visser-Cost syndrome

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines ( and How are genetic conditions and genes named? ( in the Handbook.

What if I still have specific questions about corticosterone methyloxidase deficiency?

Ask the Genetic and Rare Diseases Information Center (

What glossary definitions help with understanding corticosterone methyloxidase deficiency?

acidosis ; adrenal glands ; aldosterone ; autosomal ; autosomal recessive ; cell ; chloride ; coma ; congenital ; deficiency ; dehydration ; enzyme ; failure to thrive ; familial ; gene ; hormone ; hyperkalemia ; hyponatremia ; inherited ; ions ; methyl ; Na ; NaCl ; oxidase ; population ; potassium ; precursor ; prevalence ; recessive ; sodium ; sodium chloride ; syndrome ; wasting

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Leshinsky-Silver E, Landau Z, Unlubay S, Bistrizer T, Zung A, Tenenbaum-Rakover Y, Devries L, Lev D, Hanukoglu A. Congenital hyperreninemic hypoaldosteronism in Israel: sequence analysis of CYP11B2 gene. Horm Res. 2006;66(2):73-8. Epub 2006 May 29. (
  • López-Siguero JP, García-García E, Peter M, Sippell WG. Aldosterone synthase deficiency type I: hormonal and genetic analyses of two cases. Horm Res. 1999;52(6):298-300. (
  • Nguyen HH, Hannemann F, Hartmann MF, Malunowicz EM, Wudy SA, Bernhardt R. Five novel mutations in CYP11B2 gene detected in patients with aldosterone synthase deficiency type I: Functional characterization and structural analyses. Mol Genet Metab. 2010 Aug;100(4):357-64. doi: 10.1016/j.ymgme.2010.04.016. Epub 2010 May 21. (
  • Peter M, Dubuis JM, Sippell WG. Disorders of the aldosterone synthase and steroid 11beta-hydroxylase deficiencies. Horm Res. 1999;51(5):211-22. Review. (
  • Peter M, Fawaz L, Drop SL, Visser HK, Sippell WG. Hereditary defect in biosynthesis of aldosterone: aldosterone synthase deficiency 1964-1997. J Clin Endocrinol Metab. 1997 Nov;82(11):3525-8. (
  • Peter M. Congenital hyperreninemic hypoaldosteronism: are there different forms? Horm Res. 2006;66(2):79-80. Epub 2006 May 29. (
  • Rösler A, White PC. Mutations in human 11 beta-hydroxylase genes: 11 beta-hydroxylase deficiency in Jews of Morocco and corticosterone methyl-oxidase II deficiency in Jews of Iran. J Steroid Biochem Mol Biol. 1993 Apr;45(1-3):99-106. Review. (
  • White PC. Aldosterone synthase deficiency and related disorders. Mol Cell Endocrinol. 2004 Mar 31;217(1-2):81-7. Review. (


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? ( in the Handbook.

Reviewed: November 2013
Published: February 8, 2016