Cytogenetic notation
Encyclopedia
The following table summarizes symbols and abbreviations used in cytogenetics
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Cytogenetics
Cytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes. It includes routine analysis of G-Banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ...
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| Symbol | Description |
|---|---|
| , | Separates modal number (total number of chromosomes), sex chromosomes, and chromosome abnormalities |
| - | Loss of a chromosome |
| Grouping for breakpoints and structurally altered chromosomes | |
| + | Gain of a chromosome |
| ; | Separates rearranged chromosomes and breakpoints involving more than one chromosome |
| / | Separates cell lines or clones |
| // | Separates recipient and donor cell lines in bone marrow transplants |
| del | Deletion |
| der | Derivative chromosome Derivative chromosome A derivative chromosome is a structurally rearranged chromosome generated either by a rearrangement involving two or more chromosomes or by multiple aberrations within a single chromosome... |
| dic | Dicentric chromosome Dicentric chromosome Dicentric chromosome is an aberrant chromosome having two centromeres. Dicentric chromosomes form when two chromosome segments , each with a centromere, fuse end to end, with loss of their acentric fragments... |
| dn | de novo (not inherited) chromosomal abnormality |
| dup | Duplication Gene duplication Gene duplication is any duplication of a region of DNA that contains a gene; it may occur as an error in homologous recombination, a retrotransposition event, or duplication of an entire chromosome.The second copy of the gene is often free from selective pressure — that is, mutations of it have no... of a portion of a chromosome |
| fra | Fragile site (usually used with Fragile X syndrome Fragile X syndrome Fragile X syndrome , Martin–Bell syndrome, or Escalante's syndrome , is a genetic syndrome that is the most commonly known single-gene cause of autism and the most common inherited cause of intellectual disability... ) |
| h | Heterochromatic Heterochromatin Heterochromatin is a tightly packed form of DNA, which comes in different varieties. These varieties lie on a continuum between the two extremes of constitutive and facultative heterochromatin... region of chromosome |
| i | Isochromosome Isochromosome An isochromosome is a chromosome that has lost one of its arms and replaced it with an exact copy of the other arm. This is sometimes seen in some females with Turner syndrome or in tumor cells. This may also cause an isochromosome to have two centromeres The chromosome arm is already copied during... |
| ins | Insertion Insertion (genetics) In genetics, an insertion is the addition of one or more nucleotide base pairs into a DNA sequence. This can often happen in microsatellite regions due to the DNA polymerase slipping... |
| inv | Inversion Chromosomal inversion An inversion is a chromosome rearrangement in which a segment of a chromosome is reversed end to end. An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself. Inversions are of two types: paracentric and pericentric.Paracentric inversions do not include the... |
| .ish | Precedes karyotype Karyotype A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28... results from FISH Fluorescent in situ hybridization FISH is a cytogenetic technique developed by biomedical researchers in the early 1980s that is used to detect and localize the presence or absence of specific DNA sequences on chromosomes. FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high... analysis |
| mar | Marker chromosome |
| mat | Maternally-derived chromosome rearrangement |
| p | Short arm of a chromosome |
| pat | Paternally-derived chromosome rearrangement |
| psu dic | pseudo dicentric - only one centromere Centromere A centromere is a region of DNA typically found near the middle of a chromosome where two identical sister chromatids come closest in contact. It is involved in cell division as the point of mitotic spindle attachment... in a Dicentric chromosome Dicentric chromosome Dicentric chromosome is an aberrant chromosome having two centromeres. Dicentric chromosomes form when two chromosome segments , each with a centromere, fuse end to end, with loss of their acentric fragments... is active |
| q | Long arm of a chromosome |
| r | Ring chromosome |
| t | Translocation Chromosomal translocation In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A gene fusion may be created when the translocation joins two otherwise separated genes, the occurrence of which is common in cancer. It is detected on... |
| ter | Terminal end of arm (e.g. 2qter refers to the end of the long arm of chromosome 2) |
| tri | Trisomy Trisomy A trisomy is a type of polysomy in which there are three copies, instead of the normal two, of a particular chromosome. A trisomy is a type of aneuploidy .-Description and causes:... |
| trp | Triplication of a portion of a chromosome |