Genome-Wide Association/Exome Sequencing

The classic linkage approach to finding disease-causing genes is difficult to apply in mental health disorders. This entry describes the modern approach to gene discovery, which has been extraordinarily successful in identifying genes involved in mental health disorders.

Every person has two copies of every gene—one from each parent, although there are exceptions, such as genes that map to the sex chromosomes in men. The two copies are referred to as alleles. Another exception to the two copies for every gene rule is copy number variants (CNVs). At CNV loci, a person may have only one (copy loss) or more than two copies (copy gains) of affected genes. Classic genetic disorders are generally caused by mutations affecting a single allele of a gene (autosomal dominant disorders; ...