Karyotyping

Karyotyping

The cytogenetic technique used to examine and arrange chromosomes in pairs according to size in an ideogram.

Cytogenetics

The study of the structure and properties of chromosomes, including their behavior during mitosis and meiosis, chromosomal influence on phenotype, and factors causing chromosomal changes.

Karyotype

The complete set of chromosomes in a eukaryotic cell, represented in an ideogram and classified based on the position of the centromere and length of chromosomal arms.

Ideogram

A diagrammatic representation of the karyotype, showing all pairs of chromosomes arranged by size.

Eukaryotic chromosomes

Chromosomes with a specific structure consisting of nucleosomes, DNA double helix, coils, supercoils, and histones.

Homologous chromosomes

Chromosomes with similar structures, including centromeres, replicated from paternal and maternal chromosomes.

Metaphase

The stage of cell division where chromosomes are condensed and visible under a microscope, chosen for karyotyping due to their visibility.

Colchicine

A substance used to arrest cells at metaphase during karyotyping.

Banding pattern

The characteristic pattern of bands on chromosomes, represented in an ideogram and used for identification.

Chromosome abnormalities

Changes in the number or structure of chromosomes, detected through karyotyping and used for diagnosing genetic diseases, birth defects, and certain disorders.

Cytogenetic nomenclature

The standardized system for naming and describing chromosomal abnormalities, including terms like deletion, duplication, translocation, and more.

Trisomy

The presence of an extra chromosome, such as Trisomy 21 (Down syndrome) or Trisomy 13 (Patau syndrome).

Monosomy

The absence of one chromosome, such as Turner syndrome (X instead of XX).

Deletions

Missing pieces of chromosomes or genetic material, which can be small and difficult to detect.

Duplications

Extra genetic material present on any chromosome.

Translocations

Pieces of chromosomes breaking off and reattaching to another chromosome, which can be balanced or unbalanced.

Genetic rearrangement

Genetic material present on a chromosome but not in its usual location, which can coexist with duplication or deletion.

Mosaic Down syndrome

A diagnosis indicating the presence of three copies of chromosome 21 (trisomy 21) in some cells but not all, resulting in a mosaic pattern.