Sulfotransferase that utilizes 3'-phospho-5'-adenylyl sulfate (PAPS) as sulfonate donor to catalyze the transfer of sulfate to position 6 of non-reducing N-acetylglucosamine (GlcNAc) residues of keratan (PubMed:11352640, PubMed:11278593, PubMed:12218059, PubMed:17690104). Cooperates with B4GALT4 galactosyltransferase and B3GNT7 N-acetylglucosaminyltransferase to construct and elongate the sulfated disaccharide unit [->3Galbeta1->4(6-sulfoGlcNAcbeta)1->] within keratan sulfate polymer. Involved in biosynthesis of keratan sulfate in cornea, with an impact on proteoglycan fibril organization and corneal transparency (PubMed:17690104, PubMed:11278593, PubMed:12218059). Involved in sulfation of endothelial mucins such as GLYCAM1 (PubMed:11352640). 3'-phosphoadenylyl sulfate + keratan = adenosine 3',5'-bisphosphate + keratan 6'-sulfate. Expressed in cornea. Mainly expressed in brain. Also expressed in spinal cord and trachea. The disease is caused by variants affecting the gene represented in this entry. CHST6 homozygous missense mutations have been observed in patients with macular corneal dystrophy type I, while type II patients show a large deletion and replacement in the upstream region of CHST6. The only missense mutation for type II is Cys-50, which is heterozygous with a replacement in the upstream region on the other allele of CHST6. Belongs to the sulfotransferase 1 family. Gal/GlcNAc/GalNAc subfamily. PubMed:12824236 reported a Gly-204 variant, however according to their results reported in figure 1, it is a Gln-204 variant.