The Gene Callability Atlas

A gene can read perfectly and still hide the answer.

An aggregation of sequencing blind-spot knowledge across 19,250 human genes, from 16 public sources, with evidence behind every flag.

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This symbol is not in the Blindspot dataset, which carries the 19,250 genes with a RefSeq Select transcript on chromosomes 1–22, X and Y.

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ⓘExon models from RefSeq Select; difficult-region overlap and intervals from the GIAB stratifications; category flags from the reference-assembly comparison; gene validity and dosage from ClinGen. Every figure is traceable to a documented source.
The problem
1 in 3human genes have at least one documented blind spot — in their coding sequence, promoter or copy number
1 in 9human genes have coding sequence that standard short reads can’t reliably call
1 in 5pathogenic ClinVar variants sit in a region GIAB flags as difficult to sequence
10,657coding exons lie entirely in repeated sequence, where a short read may land on the wrong copy

Measured from the Blindspot database on 2 October 2026. How each figure is measured.

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The evidence base →
Blindspot Genetics is an informational and educational reference tool. It surfaces published, gene- and assembly-level sequencing limitations to support test selection and clinical understanding. It does not provide medical advice, make patient-specific recommendations, or replace confirmatory testing, laboratory judgment, or genetic counseling. Clinical decisions remain the responsibility of the ordering provider and testing laboratory. Every figure is traceable to peer-reviewed literature or a documented internal pipeline.