A method of identifying a gene associated with a disease or pathological condition of the disease includes: a) obtaining a first group of exome sequences from a first population suffering from the disease or pathological condition and a second group of exome sequences from a second population not having the disease or pathological condition; b) identifying one or more variants in the first group by comparing it with the second group, and optionally with a public database, to generate a first set of variant data; c) applying a variant quality score calibration tool with a truth sensitivity threshold to remove false-positive variants having a sensitivity lower than the threshold and background variants from the first set of variant data so as to obtain a second set of variant data; d) removing synonymous variants from the second set of variant data to obtain a third set of variant data; and e) identifying one or more deleterious variants from the third set of variant data using a gene burden analysis, optionally generating a fourth set of variant data.