karüotüübi

Karyotype refers to the complete set of chromosomes in a cell or organism. It is typically observed during metaphase of cell division when chromosomes are condensed and most visible. A karyotype analysis involves arranging the chromosomes in pairs, from largest to smallest, and numbering them. This ordered display, often called a karyogram or idiogram, allows for the identification of chromosomal abnormalities.

Human cells normally have 23 pairs of chromosomes: 22 pairs of autosomes and one pair of sex chromosomes (XX for females and XY for males), totaling 46 chromosomes. Deviations from this standard number or structure can lead to various genetic disorders. For example, Down syndrome is caused by trisomy 21, meaning an individual has three copies of chromosome 21 instead of the usual two. Similarly, Klinefelter syndrome in males results from an extra X chromosome (XXY).

Karyotype analysis is a crucial diagnostic tool in genetics. It is used to identify chromosomal abnormalities associated with developmental delays, infertility, and certain types of cancer. It can also be used to determine the sex of an individual and to detect structural changes in chromosomes, such as translocations, deletions, or duplications. The process typically involves obtaining a cell sample (like blood or amniotic fluid), culturing the cells, arresting them at metaphase, staining the chromosomes, and then capturing images for analysis and arrangement.