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KRIT1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

KRIT1 gene

The KRIT1 gene provides instructions for making a protein that strengthens blood vessel junctions and prevents leakage, playing a critical role in vascular integrity.

Normal Function

The KRIT1 gene (also known as CCM1) provides instructions for making a protein that strengthens the interactions between cells that form blood vessels and limits leakage from the vessels. The KRIT1 protein interacts with other proteins to form a complex found in the junctions that connect neighboring cells. As part of this complex, the KRIT1 protein helps turn off (suppress) a signaling molecule known as RhoA-GTPase. This molecule regulates the actin cytoskeleton, a network of fibers that provides structural framework to the cell. When turned on, RhoA-GTPase stimulates the formation of actin fibers, which has been linked to weakened junctions between cells and increased leakage from blood vessels.

Health Conditions Related to Genetic Changes

Cerebral cavernous malformation

More than 100 KRIT1 gene mutations have been identified in families with cerebral cavernous malformations, which are collections of weak, leaky blood vessels in the brain.

  • Virtually all of these mutations place a premature stop signal in the instructions for making the KRIT1 protein, preventing adequate production.
  • A shortage of this protein impairs the function of the cellular complex, causing RhoA-GTPase signaling to be turned on abnormally.
  • This weakens cellular junctions and increases the permeability of blood vessel walls.
  • Increased leakage into the brain can cause health problems such as headaches, seizures, and bleeding in the brain (cerebral hemorrhage).

Mutations in the KRIT1 gene account for up to 50 percent of all familial cerebral cavernous malformation cases. One particular mutation (1363C>T) is responsible for up to 70 percent of cases in people of Hispanic heritage.

Other Names for This Gene

  • ankyrin repeat-containing protein Krit1
  • CAM
  • CCM1
  • cerebral cavernous malformations 1
  • krev interaction trapped 1
  • KRIT1_HUMAN

Frequently Asked Questions

Yes, first-degree relatives should be offered genetic counseling and testing. If a pathogenic variant is identified, regular MRI surveillance (every 2–3 years) is recommended, even if the individual is asymptomatic, to detect new or enlarging lesions early.===
DNA test from a peripheral blood sample is the most common method. In some cases, a skin biopsy can provide DNA, but blood is preferred for its ease and reliability. The test looks for pathogenic variants, including the common 1363C>T mutation.
Patients presenting with headaches, seizures, or focal neurological deficits that imaging reveals as small, well-circumscribed vascular lesions (cavernous malformations) should raise suspicion. If multiple lesions are found or the family history includes similar brain vascular abnormalities, KRIT1 mutation testing is advised.
Most lesions are monitored if asymptomatic. Surgery or stereotactic radiosurgery is considered when the lesion causes recurrent hemorrhage, significant seizures, or progressive neurological deficits. The decision depends on lesion size, location, and symptom severity.
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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