text: <unk>  allows the<unk>  diagnosis of vulnerabilities to inherited diseases, and can also be used to determine a person's ancestry. Normally, every person carries two copies of every gene, one inherited from their mother, one inherited from their father. The human genome is believed to contain around 20,000 - 25,000 genes. In addition to studying chromosomes to the level of individual genes,<unk>  in a broader sense includes biochemical tests for the possible presence of<unk>  diseases, or mutant forms of genes associated with increased risk of developing<unk>  disorders.<unk>  identifies changes in chromosomes, genes, or proteins. Most of the time,<unk>  is used to find changes that are associated with inherited disorders. The results of a<unk>  test can confirm or rule out a suspected<unk>  condition or help determine a person's chance of developing or passing on a<unk>  disorder. Several hundred<unk>  tests are currently in use, and more are being developed.
  Since<unk>  may open up ethical or psychological problems,<unk>  is often accompanied by<unk>  counseling.
option_0: Genetic testing
option_1: Nerve conduction study
option_2: Electromyography
option_3: Electrophysiology
option_4: Brugada syndrome genetic testing
option_5: Electrophysiologic study
option_6: Endomyocardial biopsy
option_7: Cognitive neuropsychology