HomeGeneticsGeneCYP27A1 gene
Back to Gene
CYP27A1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

CYP27A1 gene

The CYP27A1 gene produces an enzyme essential for cholesterol breakdown, and mutations in this gene can lead to a disorder involving the abnormal storage of fats in the body.

Normal Function

The CYP27A1 gene is a member of the cytochrome P450 gene family. Enzymes produced from these genes are involved in the formation and breakdown of various molecules and chemicals within cells. The CYP27A1 gene provides instructions for producing an enzyme called sterol 27-hydroxylase.

This enzyme is located in the mitochondria, where it is involved in the pathway that breaks down cholesterol to form acids used to digest fats (bile acids). Specifically, sterol 27-hydroxylase breaks down cholesterol to form a bile acid called chenodeoxycholic acid. The formation of bile acids from cholesterol is the body's main pathway for cholesterol removal, and this enzyme plays a key role in maintaining normal cholesterol levels.

Health Conditions Related to Genetic Changes

Cerebrotendinous xanthomatosis

At least 90 mutations that cause cerebrotendinous xanthomatosis have been identified in the CYP27A1 gene. This disorder is characterized by the abnormal storage of fats (lipids) in many areas of the body.

  • Mechanism: Most mutations change one amino acid in the sterol 27-hydroxylase enzyme, such as the common Arg362Cys mutation, which disrupts the enzyme's function.
  • Metabolic Impact: Because the body cannot properly form chenodeoxycholic acid, alternative pathways are used. A molecule called cholestanol is produced and accumulates in blood and tissues.
  • Symptoms: Cholesterol and cholestanol accumulate throughout the body's tissues, causing the signs and symptoms of the disorder. While tissue levels of cholesterol are high, levels in the blood are typically normal.

Genomic Location

The CYP27A1 gene is found on chromosome 2.

Frequently Asked Questions

Early signs often appear in infancy or early childhood and include chronic diarrhea, which can be mistaken for other gastrointestinal issues. Other early indicators may include cataracts (clouding of the lens) in young children, failure to thrive, and developmental delays. As the child grows, tendon xanthomas (fatty deposits in tendons) may become visible, particularly in the Achilles tendons, though these are more common in later childhood or adulthood.
Cerebrotendinous xanthomatosis is an autosomal recessive disorder, meaning a person must inherit two mutated copies of the CYP27A1 gene, one from each parent, to develop the condition. If both parents are carriers (having one mutated copy and one normal copy), there is a 25 percent chance with each pregnancy that the child will inherit two mutated copies and have the disorder. There is a 50 percent chance the child will be a carrier and a 25 percent chance the child will inherit two normal copies.
Diagnosis often relies on measuring specific lipid markers rather than standard cholesterol panels. Clinicians look for elevated levels of cholestanol in the blood and urine, as well as increased levels of bile alcohol. Genetic testing for mutations in the CYP27A1 gene confirms the diagnosis. Because blood cholesterol is typically normal, a standard lipid profile may miss the condition, so specific biochemical tests are required.
No, diet alone is insufficient to manage this condition. While a low-cholesterol diet is recommended, the primary treatment involves pharmacological intervention to replace the missing bile acid. Patients are typically prescribed chenodeoxycholic acid (CDCA) to suppress the production of cholestanol and prevent its accumulation in tissues. Without this medication, neurological and physical symptoms can progress despite dietary changes.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

kontakt@hittavard.se

Ⓒ 2024. Alla rättigheter förbehålls av juxt ab

Sök
Om ossVillkor och policyVanliga frågorKontakta oss