BackgroundRecent advances in high-throughput DNA sequencing technologies have expanded our understanding of the molecular underpinnings of various genetic disorders and have led to increased utilization of genomic tests by clinicians. However, each test can generate thousands of variants, and given the paucity of functional studies assessing each one of them, experimental validation of a variant's clinical significance is not feasible for clinical laboratories. Therefore, many variants are reported as variants of unknown clinical significance due to this gap. However, the creation of large variant databases like the Genome Aggregation Database has significantly improved the interpretation of novel variants. Specifically, pathogenicity prediction for novel missense variants can now utilize features describing regional variant constraint. Constrained genomic regions are those that have an unusually low variant counts in the general population. Earlier pathogenicity classifiers tried to capture these regions using protein domains.