RESUMO
The development of new genetic diagnostic, and hence therapeutic possibilities, has brought the realization that genetic disease is now an integral part of medical practice. Advances in cytogenetic and molecular testing have drastically improved the ability to diagnose with certainty many previously unrecognized genetic diseases. However, this advance in technology does not come without new questions. New tests are not always the most cost-effective ones and some have significant diagnostic limitations. Genetic tests fall under three major categories: chromosomal genetic tests; molecular genetic tests [DNA and gene tests]; and biochemical genetic tests [measuring the amount and activity of proteins]. This review article focuses on chromosomal anomalies and cytogenetic tests. The different types of cytogenetic tests, their indications, and the advantages and disadvantages of each of them are discussed. This review will also present the strategy of choice for each one of these tests depending on the type of chromosomal anomalies that we are searching for and the available specimen for diagnosis. Chromosomal anomalies represent one of the entities of genetic diseases. A large number of cytogenetic tests exist for diagnosis of these chromosomal anomalies. However, the choice of cytogenetic test to be carried out should be based on clinical indications, on the type and size of cytogenetic anomaly that we are searching for, and on the available specimen for diagnosis