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Disease Profile

Non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

#N/A

ICD-10

#N/A

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

LOCAH; Non classic congenital adrenal hyperplasia; NCCAH;

Summary

Non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NCAH) is a milder and later onset form of a genetic condition known as congenital adrenal hyperplasia. Some people affected by the condition have no associated signs and symptoms while others experience symptoms of androgen (male hormone) excess. Women with NCAH are generally born with normal female genitalia. Later in life, signs and symptoms of the condition can vary but may include hirsutism, frontal baldness, delayed menarche (first period), menstrual irregularities, and infertility. Little has been published about males with NCAH. They may have early beard growth and relatively small testes. Typically, they have normal sperm counts. NCAH is caused by changes (mutations) in the CYP21A2 gene and is inherited in an autosomal recessive manner. Treatment is only necessary in people who are symptomatic and may include a glucocorticoid called dexamethasone.[1][2][3]

Symptoms

The signs and symptoms of non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NCAH) may develop any time after birth. Affected people generally experience symptoms of androgen (male hormone) excess such as acne, premature development of pubic hair, accelerated growth, advanced bone age, and reduced adult height.[2][3]

Women with NCAH are generally born with normal female genitalia. Later in life, signs and symptoms of the condition can vary but may include hirsutism, frontal baldness, delayed menarche (first period), menstrual irregularities, and infertility.[2][3]

Little has been published about males with NCAH. They may have early beard growth and relatively small testes. Typically, they have normal sperm counts.[2][3]

Some men and women affected by NCAH have no signs or symptoms of the condition.[9818]

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
Percent of people who have these symptoms is not available through HPO
Abnormal thorax morphology
Abnormality of the chest
0000765
Adrenal hyperplasia
Enlarged adrenal glands
0008221
Adrenogenital syndrome
0000840
Autosomal recessive inheritance
0000007
Growth abnormality
Abnormal growth
Growth issue

[ more ]

0001507
Gynecomastia
Enlarged male breast
0000771
Hypertension
0000822
Hypoglycemia
Low blood sugar
0001943
Hypospadias
0000047
Recurrent fever
Episodic fever
Increased body temperature, episodic
Intermittent fever

[ more ]

0001954
Renal salt wasting
Loss of salt in urine
0000127

Cause

Non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NCAH) is caused by changes (mutations) in the CYP21A2 gene. This gene provides instructions for making an enzyme called 21-hydroxylase, which is found in the adrenal glands. The adrenal glands are cone-shaped organs that sit on top of the kidneys and are responsible for releasing various types of hormones that the body needs to function. Mutations in CYP21A2 lead to deficient levels of 21-hydroxylase which cause low levels of hormones such as cortisol and/or aldosterone and an overproduction of androgens (male hormones such as testosterone). Cortisol is a hormone that affects energy levels, blood sugar levels, blood pressure, and the body's response to stress, illness, and injury. Aldosterone helps the body maintain the proper level of sodium (salt) and water and helps maintain blood pressure. Irregular levels of these hormones lead to the signs and symptoms of NCAH.[9818]

The amount of functional 21-hydroxylase enzyme determines the severity of the disorder. People with NCAH have CYP21A2 mutations that result in the production of reduced amounts of the enzyme, but more enzyme than the classic form of congenital adrenal hyperplasia.[9818]

Diagnosis

A diagnosis of non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NCAH) is often suspected based on the presence of characteristic signs and symptoms. Additional testing can then be ordered to confirm the diagnosis. This may include a blood test to measure the concentration of 17-hydroxyprogesterone (17-OHP) and/or an adrenocorticotropic hormone (ACTH) stimulation test. An ACTH stimulation test involves measuring the concentration of 17-OHP in the blood before ACTH is administered and 60 min after ACTH is given.[1][2]

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

    Newborn Screening

    • Baby's First Test is the nation's newborn screening education center for families and providers. This site provides information and resources about screening at the local, state, and national levels and serves as the Clearinghouse for newborn screening information.

      Treatment

      In some cases, people affected by non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (NCAH) may not require any treatment. Many are asymptomatic throughout their lives, although symptoms may develop during puberty, after puberty, or post partum. If symptoms are present, a glucocorticoid called dexamethasone is often recommended. Dexamethasone can treat irregular menstruation, acne, and excess body hair (hirsutism).[1][2]

      Organizations

      Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

      Organizations Supporting this Disease

        Learn more

        These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

        Where to Start

        • The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) provides information related to the health of children, adults, and families. Click on the link to view information on this topic.
        • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
        • Genetics Home Reference (GHR) contains information on Non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency. This website is maintained by the National Library of Medicine.
        • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
        • The Screening, Technology And Research in Genetics (STAR-G) Project has a fact sheet on this condition, which was written specifically for families that have received a diagnosis as a result of newborn screening. This fact sheet provides general information about the condition and answers questions that are of particular concern to parents.

          In-Depth Information

          • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
          • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
          • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
          • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
          • PubMed is a searchable database of medical literature and lists journal articles that discuss Non-classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency. Click on the link to view a sample search on this topic.

            References

            1. Merke DP & Nieman LK. Diagnosis and treatment of nonclassic (late-onset) congenital adrenal hyperplasia due to 21-hydroxylase deficiency. UpToDate. September 16, 2014; https://www.uptodate.com/contents/diagnosis-and-treatment-of-nonclassic-late-onset-congenital-adrenal-hyperplasia-due-to-21-hydroxylase-deficiency. Accessed 7/6/2015.
            2. Nimkarn A, Gangishetti PK, Yau M, New MI. 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia. GeneReviews. Updated Feb 4, 2016; https://www.ncbi.nlm.nih.gov/books/NBK1171/.
            3. Lynnette K Nieman, MD. Genetics and clinical presentation of nonclassic (late-onset) congenital adrenal hyperplasia due to 21-hydroxylase deficiency. UpToDate. September 2015; Accessed 10/19/2015.
            4. Congenital Adrenal Hyperplasia. National Organization for Rare Disorders. 2015; https://rarediseases.org/rare-diseases/congenital-adrenal-hyperplasia/.

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