CHST7 (carbohydrate sulfotransferase 7) is an X-linked enzyme that catalyzes the sulfation of carbohydrate moieties, specifically transferring sulfate groups to position 6 of N-acetylglucosamine and N-acetylgalactosamine residues 1. The enzyme preferentially acts on mannose-linked GlcNAc and contributes to chondroitin sulfate biosynthesis, playing essential roles in craniofacial development 1. CHST7 functions in the Golgi apparatus as part of glycosaminoglycan modification pathways that affect extracellular matrix composition 2. Disease relevance includes cancer susceptibility, where CHST7 hypermethylation in blood cells associates with increased colorectal cancer risk, particularly in females 3, and elevated serum CHST7 serves as a diagnostic biomarker for lung cancer differentiation from pulmonary inflammations 4. CHST7 is also implicated in pituitary adenoma differentiation, with methylation status affecting SF-1 lineage development 5, and has been identified as a novel candidate risk gene for autism spectrum disorder 6. Additionally, CHST7 shows association with Alzheimer's disease risk and demonstrates escape from X-chromosome X 7. The gene's expression and methylation patterns are sensitive to environmental exposures like PFAS 8.