There are at least three four kind of alleles that have unknown biochemical function

* Alleles PGx alleles that are listed by PharmGKB, but has no functional status* Unknown alleles with variants that cause changes to the protein, but which are not classified by PharmGKB* Alleles Unknown alleles with variants that do not cause changes to the protein, and which are not classified by PharmGKB

The There is no explicit dosing recommendation for patients with an unknown biochemical function allele on at least one chromatid is to follow the normal medication advice. This means that normal there is no special medication is recommended, recommendation '''even if the sister-chromatid has ''No function'' or ''Increased function'''''.

This dosing recommendation is very conservative, and the question is whether the allele with ''Unknown function'' should rather be treated as a ''Normal function'' allele(thereby assigning modified dosing recommendations to e.g. ''Unknown function''/''No function''-patients).

[[Normal function]] means that the biochemical function of the allele is sufficiently close to the average that a normal medication recommendation can be used.There are at least three kind of alleles that have Alleles with normal biochemical functionare

* Any allele alleles with no variants (these "wildtype" alleles are usually explicitly classified as ''Normal function'' by PharmGKB, but not always)In addition, at least in the world of SNP-arrays, the definition of ''Normal function'' alleles and ''Unknown function'' alleles are overlapping* Alleles that is are '''not''' classified (by PharmGKB* An allele with no variants) have ''Normal function''

In other words: the definitions ''Normal function'' and ''Unknown function'' are partially overlapping. If we replace the ''Unknown function'' classification with ''Normal function'', dosing recommendations for these patients have to be changed accordingly.