CSV call
GA reports two allele letters observed for a marker in the source file.
Chapter 2 / Orientation
A genotype call becomes a variant candidate only after context is added.
A result such as GA is an observed call. Annotation systems usually require chromosome, position, reference allele, alternate allele, genome build, and strand confidence.
Coordinate system
The coordinate must be tied to a genome build before it can be compared across resources.
Reference orientation
The reference allele and strand determine whether a candidate can be written as G>A, A>G, or something else.
Variant candidate
The candidate is useful for lookup and modeling, but it should stay labeled as inferred until checked.
Practical rule
Do not treat the result field as variant notation. Treat it as an observed genotype call that must be oriented against a reference before deeper annotation or clinical review.