Pathogenic variants (disease-causing) in the GALNT12 gene have been implicated in an increased risk of colorectal cancer. While the evidence is still emerging, pathogenic variants in GALNT12 are thought to contribute to hereditary colorectal cancer predisposition, though penetrance (the likelihood of developing cancer if a mutation is present) is not yet fully defined. Management of GALNT12–related colorectal cancer risk includes regular surveillance tailored to guidelines to detect tumors early. GALNT12 variants are not known to be more common in the Ashkenazi Jewish population.
Pathogenic variants in GALNT12 exhibit autosomal dominant inheritance. This means there is a 50% chance the condition can be passed from generation-to-generation. First degree relatives (parents, siblings, children) have a 50% chance to have the same pathogenic variant whereas second degree relatives (grandparents, aunts/uncles, nieces/nephews, half-siblings) have a 25% chance. More distant relatives have lower chances of having the same pathogenic variant when one is identified in the family.
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Written December 2025
