S4 collection of QTL summary statistics keyed by the identity
tuple (study, context, trait). Each element is that tuple's
per-variant GRanges – variant_id plus the per-variant
Z / N / MAF mcols.
Details
Required columns: study, context and trait;
the 3-tuple is unique. The class-level slots inherited from
SumStatsBase – ldSketch, genome and
qcInfo – apply uniformly to every row, and qcInfo records
which summaryStatsQc passes have run.
See also
QtlSumStats for the constructor and
GwasSumStats for the GWAS counterpart.