Description: The karyotype screening is a diagnostic test to identify chromosomal abnormalities. This technique allows the analysis of the number and structure of chromosomes in a cell, providing crucial information about an individual’s genetics. By obtaining a karyotype, which is a visual representation of chromosomes organized in pairs, alterations such as trisomies, monosomies, and translocations can be detected. The screening is commonly performed on blood samples, amniotic fluid, or tissue, and is carried out using cell culture and staining techniques. The importance of karyotype screening lies in its ability to assist in the diagnosis of various genetic conditions and syndromes, as well as in the evaluation of reproductive health. Additionally, it is a valuable tool in genetic research, allowing scientists to study genetic variability and the molecular bases of diseases. In summary, karyotype screening is an essential procedure in medical genetics and bioinformatics, significantly contributing to the understanding of chromosomal abnormalities and their impact on human health.
History: Karyotype screening has its roots in the advances of cytogenetics in the 20th century. In 1956, the normal number of human chromosomes was established as 46, thanks to the work of scientists like Joe Hin Tjio and Albert Levan. This discovery enabled the development of techniques for the visualization and analysis of chromosomes, facilitating the identification of chromosomal abnormalities. Over the decades, karyotype screening has evolved with the introduction of more sophisticated methods, such as fluorescence in situ hybridization (FISH) and comparative genomics, which have improved the accuracy and speed of diagnoses.
Uses: Karyotype screening is primarily used in the diagnosis of genetic disorders such as Down syndrome, Turner syndrome, and Klinefelter syndrome. It is also applied in the evaluation of recurrent miscarriages and in the investigation of infertility. In the prenatal context, it is used to detect chromosomal abnormalities in fetuses through amniocentesis or chorionic villus sampling. Additionally, it is an important tool in oncology, where it is used to identify chromosomal alterations in tumor cells, which can influence cancer treatment and prognosis.
Examples: An example of karyotype screening use is in prenatal diagnosis, where Down syndrome can be identified in a fetus from an amniotic fluid sample. Another case is in oncology, where it has been used to detect the translocation of chromosome 9 and 22, known as the Philadelphia chromosome, in patients with chronic myeloid leukemia, which helps guide appropriate treatment.
