6-O-sulfation enzyme which catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to position 6 of the N-sulfoglucosamine residue (GlcNS) of heparan sulfate. Critical for normal neuronal development where it may play a role in neuron branching. May also play a role in limb development. May prefer iduronic acid. 3'-phosphoadenylyl sulfate + alpha-D-glucosaminyl-[heparan sulfate](n) = 6-sulfo-alpha-D-glucosaminyl-[heparan sulfate](n) + adenosine 3',5'-bisphosphate + H(+) Expressed in fetal brain and liver. N-glycosylated. According to PubMed:17405882 most mice die between embryonic day 15.5 and the perinatal stage. Those that survive are considerably smaller than their wild-type littermates and exhibit development abnormalities including a reduction in the number of fetal microvessels in the labyrinthine zone of the placenta. However, according to PubMed:18196599, pups are viable and grossly normal at birth. During early adulthood, however, mice fail to thrive and exhibit growth retardation, bodyweight loss, enlargement of airspaces in the lung and, in some cases, lethality. Belongs to the sulfotransferase 6 family.