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GALC gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

GALC gene

The GALC gene provides instructions for producing the enzyme galactosylceramidase, which is essential for breaking down specific fats in the nervous system.

Normal Function

The GALC gene provides instructions for making an enzyme called galactosylceramidase. Through a process called hydrolysis, this enzyme uses water molecules to break down certain fats called galactolipids, which are found primarily in the nervous system and kidneys.

Within cells, galactosylceramidase is found in enzyme-filled sacs called lysosomes where it hydrolyzes specific galactolipids, including galactosylceramide and psychosine. Galactosylceramide is an important component of myelin, the protective covering around certain nerve cells that ensures the rapid transmission of nerve impulses. Its breakdown by galactosylceramidase is part of the normal turnover of myelin that occurs throughout life. Psychosine, which is toxic to cells, forms during the production of myelin and is quickly broken down by galactosylceramidase. Under normal conditions, tissues contain very little psychosine.

Health Conditions Related to Genetic Changes

Krabbe disease

More than 200 GALC gene mutations that cause Krabbe disease have been identified. Krabbe disease is a brain disorder that usually begins in infancy (infantile Krabbe disease) and causes movement and eating problems, impaired development, and seizures. The most common mutation in affected individuals of European ancestry (often called 30-kb del) deletes a large segment of the GALC gene. Other mutations insert additional DNA building blocks (nucleotides) into the GALC gene, delete a small number of nucleotides from the gene, or replace single nucleotides with incorrect nucleotides.

These GALC gene mutations severely reduce or eliminate the activity of the galactosylceramidase enzyme. As a result, galactosylceramide and psychosine cannot be broken down. The accumulation of these galactolipids causes damage to myelin-forming cells, which impairs the formation of myelin and leads to the loss of myelin (demyelination) in the nervous system. Without myelin, nerves in the brain and other parts of the body cannot transmit signals properly, leading to the signs and symptoms of Krabbe disease.

Some individuals develop symptoms of Krabbe disease in childhood, adolescence, or adulthood (late-onset Krabbe disease). It is thought that these individuals have a mutation that allows some activity of the galactosylceramidase enzyme, which delays onset of the condition. The severity of the condition may also be affected by the presence of additional common variations (polymorphisms) in the GALC gene that affect the activity of the galactosylceramidase enzyme.

Other Names for This Gene

  • galactocerebrosidase
  • galactosylceramide beta-galactosidase
  • GALC_HUMAN
  • GALCERase

Frequently Asked Questions

HSCT is the only therapy shown to slow disease progression, but it is most effective when performed before symptoms appear or within the first few weeks of life. Children transplanted after significant neurologic decline have limited benefit. Early referral to a transplant center is essential for eligibility evaluation.
second dried‑blood spot assay to measure GALC enzyme activity is repeated, followed by molecular genetic testing to identify pathogenic GALC mutations. Some centers also perform MRI of the brain and nerve conduction studies to assess early disease involvement.
Look for progressive stiffness or weakness in the legs, difficulty feeding or swallowing, irritability, fever without infection, and loss of developmental milestones such as smiling or tracking objects. These symptoms often appear between 2‑6 months of age and merit urgent referral to a pediatric neurologist and metabolic specialist.
Options include preimplantation genetic testing (PGT‑M) with in‑vitro fertilization to select embryos without two pathogenic GALC copies, prenatal diagnostic testing (chorionic villus sampling or amniocentesis) for at‑risk pregnancies, or using donor gametes that are not carriers. Genetic counseling can help you weigh these choices.
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.

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