My 23andme results have establish that I have a double set of gs224 haplotype . I discovered that I also have identical results for all positions in the GCH1 gene.  Does it mean that I am a homozygot for this gene? Hope someone can assist; I'm new to genetics.
I also have the gs224 double-haplotype and am homozygous for all SNPs in and near GCH1. It isn't possible to say for sure that you are homozygous for the gene without full sequencing. I've had exome sequencing done which also came back homozygous, but that test does not cover introns in the gene. --Jlick (talk) 18:07, 4 August 2012 (UTC)
According to https://www.23andme.com/you/explorer/gene/?gene_name=GCH1 shows I've got heterozygosity at rs7147286, rs3783641, rs3783642. Lilly Mendel also seems pure homozygous. --- cariaso 18:13, 4 August 2012 (UTC)
I've created a Yahoo group for everyone with Gs224 flagged on their Promethease report. I don't know if this haplotype has health effects or not, but if we all compare notes then maybe we can figure out it out. If you are interested in joining, please go to http://health.groups.yahoo.com/group/GCH1discussions . Thanks! Geneoptimize (talk) 18:08, 15 August 2012 (UTC)