<unk> , also known as DNA<unk> , is used to identify changes in DNA sequence or chromosome structure.<unk>  can also include measuring the results of<unk>  changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting,<unk>  can be used to diagnose or rule out suspected<unk>  disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's<unk>  makeup.<unk>  can also be used to determine biological relatives, such as a child's biological parentage<unk>  mother and father) through DNA paternity<unk> , or be used to broadly predict an individual's ancestry.<unk>  of plants and animals can be used for similar reasons as in humans (e.g. to assess relatedness/ancestry or predict/diagnose<unk>  disorders), to gain information used for selective breeding, or for efforts to boost<unk>  diversity in endangered populations. The variety of<unk>  tests has expanded throughout the years. Early forms of<unk>  which began in the 1950s involved counting the number of chromosomes per cell. Deviations from the expected number of chromosomes (46 in humans) could lead to a diagnosis of certain<unk>  conditions such as trisomy 21 (Down syndrome) or monosomy X (Turner syndrome). In the 1970s, a method to stain specific regions of chromosomes, called chromosome banding, was developed that allowed more detailed analysis of chromosome structure and diagnosis of<unk>  disorders that involved large structural rearrangements. In addition to analyzing whole chromosomes (cytogenetics),<unk>  has expanded to include the fields of molecular<unk> s and genomics which can identify changes at the level of individual genes, parts of genes, or even single nucleotide "letters" of DNA sequence. According to the National Institutes of Health, there are tests available for more than 2,000<unk>  conditions, and one study estimated that as of 2017 there were more than 75,000<unk>  tests on the market.
Genetic testing
Muscle biopsy
Nerve biopsy
Nerve conduction study
Electromyography
Electrophysiology
Electrophysiology study
Genetic screen