Here are the major and minor alleles (Major> Minor) for the SNPs given by 23andMe with my results as well.
The GCH1 gene contains a large number of blocks of haplotypes, so it may appear you have lots of heterozygous (+/-) or homozygous (+/+) results when in reality you may have just a few because many of the SNPs are closely linked in groups that are inherited together.
(With just a cursory look, I think rs41298442 might be the only true mutation 23andMe provides, i.e., one that definitively causes disease. It's highly unlikely you would have this one and not know about it already.)
To research any SNPs of interest you can replace the rs# in the links below with any one you like:
PubMed:
http://www.ncbi.nlm.nih.gov/pubmed/?term=rs841
Snpedia:
http://www.snpedia.com/index.php/Rs841
dbSNP:
http://www.ncbi.nlm.nih.gov/SNP/snp_ref.cgi?rs=841
OpenSNP:
https://opensnp.org/snps/rs841
Google (for example):
http://www.google.com/search?hl=en&q=GCH1+rs841
Importantly, virtually no study is ever decisive until proven in the real world. Many studies lack validity (either statistically or otherwise), or are contradicted by other studies, or simply don't turn out to have relevance in real life, etc.
Most importantly, remember that no SNP by itself causes disease, by definition. A SNP may predispose to disease, but it requires a combination of other factors (e.g., other SNPs, environment, diet, epigenetics, etc) to actually cause disease.
Here are the 38 SNPs (note that I don't have any heterozygous results):
rs841 G>A AA +/+
rs41298442 T>C TT -/- (actual mutation)
i5000652 A>G AA -/-
rs41298440 G>A GG -/-
rs752688 C>T TT +/+
i5000639 G>A GG -/-
i5000654 C>T CC -/-
i5000643 G>C GG -/-
i5000649 C>A CC -/-
i5000644 C>T CC -/-
rs17253591 C>T CC -/-
rs10131232 G>A AA +/+
rs17128021 G>A GG -/-
rs4411417 T>C CC +/+
rs2878168 G>A AA +/+
rs17128028 C>T CC -/-
rs2878169 G>T GG -/-
i5000641 A>G AA -/-
rs9671371 C>T TT +/+
i5000651 T>G TT -/-
i5000655 T>A TT -/-
i5000642 A>G AA -/-
rs17128033 C>T CC -/-
rs7492600 G>T GG -/-
rs12147422 T>C TT -/-
rs3783637 C>T CC -/-
rs8004018 A>G AA -/-
rs10498472 T>G TT -/-
rs998259 C>T CC -/-
rs12885400 T>C TT -/-
rs7147286 G>A AA +/+
rs3783641 T>A AA +/+
rs3783642 T>C CC +/+
rs8017210 G>A AA +/+
i5000650 C>T CC -/-
rs56127440 G>A GG -/-
i5000645 G>A GG -/-
rs41298432 G>A GG -/-
Edit: I almost forgot, 23andMe provides a 39th "intergenic" SNP for GCH1 as well, that I am heterozygous for:
rs8007267 C>T CT +/-
See:
https://www.23andme.com/you/explorer/snp/?snp_name=rs8007267