Karyotype is a set of human chromosomes. It describes all the features of genes: size, quantity, shape. Normally, the genome consists of 46 chromosomes, of which 44 are autosomal, that is, they are responsible for hereditary traits (hair and eye color, ear shape and other).
From school lessons we remember that a person, like any other living organism, consists of a multitude of cells. At the person of them it is totaled approximately 50 trillion.
The history of biomarker diagnostics of prostate cancer (PCa) is three quarters of a century. In his studies, A.B. Gutman et al. (1938) noted a significant increase in the activity of serum acid phosphatase in men with PCa metastases.
Monogenic defects (determined by one gene) are observed more often than chromosomal defects. Diagnosis of diseases usually begins with the analysis of clinical and biochemical data, the pedigree of the proband (the person who first discovered the defect), the type of inheritance.
In multifactorial genetic diseases, a polygenic component is always present, consisting of a sequence of genes cumulatively interacting with each other.
The sex of a person is determined by a pair of chromosomes - X and Y. In women cells, there are two X chromosomes, in men's cells there is one chromosome X and one Y. The chromosome Y is one of the smallest in a karyotype, only a few genes that are not related to it regulation of sex.
Microdeletions of neighboring genes on the chromosome cause a number of very rare syndromes (Prader-Willi, Miller-Dicker, Di-Georgie, etc.). Diagnosis of these syndromes became possible due to the improvement of the method of preparation of chromosome preparations. In the event that the microdeletion can not be detected by karyotyping, DNA probes specific to the region that has undergone deletion are used.
Karyotyping is the main method for diagnosing these syndromes. It should be noted that methods for identifying chromosomal segmentation accurately identify patients with specific chromosomal abnormalities, even in cases where the clinical manifestations of these anomalies are insignificant and of little specificity. In complex cases, karyotyping can be supplemented by in situ hybridization.
To isolate polymorphic regions of DNA, bacterial enzymes are used - restriction enzymes, the product of which are restriction sites. Spontaneous mutations that occur in polymorphic sites make them resistant or, conversely, sensitive to the action of a specific restriction enzyme.
