karyótype

A karyotype is a person's complete set of chromosomes, arranged in order of size and shape. It is essentially a visual representation of the chromosomes within a cell. Humans typically have 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs are autosomes, which are the same in both males and females. The 23rd pair are sex chromosomes, which determine a person's sex. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).

Karyotyping is a laboratory technique used to examine a person's chromosomes. This process involves obtaining a sample of cells, such as blood, and then staining the chromosomes to make them visible under a microscope. The chromosomes are then arranged in a standardized format, creating the karyotype. This visual display allows geneticists to identify any abnormalities in the number or structure of chromosomes.

Deviations from a normal karyotype can indicate various genetic disorders. For example, Down syndrome is caused by an extra copy of chromosome 21 (trisomy 21). Klinefelter syndrome, affecting males, is characterized by the presence of an extra X chromosome (XXY). Karyotyping is a crucial diagnostic tool in genetics, used for prenatal diagnosis, identifying causes of infertility, and diagnosing developmental and intellectual disabilities. It plays a vital role in understanding genetic conditions and provides valuable information for genetic counseling and reproductive planning.