Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «C»:
Chromosome 5q- syndrome
Chromosome 5q- syndrome: A blood disorder due to the loss of part of the long (q) arm of chromosome 5 in myeloid (bone marrow) cells, causing refractory (treatment-resistant) anemia, and myelodysplastic syndrome that is generally associated with a good prognosis but on occasion may lead to AML (acut...
Chromosome band: One of the transverse bands produced on chromosomes by differential staining techniques. Depending on the particular staining technique, the bands are alternating light and dark or fluorescent and nonfluorescent.
Each human chromosome has a short arm ("p" for "petit") and long arm...
Chromosome banding: The treatment of chromosomes to reveal characteristic patterns of horizontal bands like bar codes.
The banding patterns lend each chromosome a distinctive appearance so the 22 pairs of human nonsex chromosomes and the X and Y chromosomes can be identified and distinguished witho...
Chromosome complement: The whole set of chromosomes for the
species. In humans, the chromosome complement (which is also called the karyotype)
consists of 46 chromosomes. ...
Chromosome disorder: An abnormal condition due to an abnormality
of the chromosomes. For example, Down syndrome (the genetic abnormality featuring three
chromosome 21s, instead of two, also referred to as trisomy 21) is a chromosome disorder. ...
Chromosome duplication: Part of a chromosome in duplicate. A particular kind of mutation involving the production of one or more copies of any piece of DNA, including sometimes a gene or even an entire chromosome.
A duplication is the opposite of a deletion.
Duplications have been important in the e...
Chromosome inversion: A chromosome segment is clipped out, turned upside down and reinserted back into the chromosome.
A chromosome inversion can be inherited and have come from one of the parents to a child. Or the inversion can appear for the first time in a child.
An inversion can be "balanced"...
Chromosome inversion, paracentric
Chromosome inversion, paracentric: A basic type of chromosome rearrangement. A segment that does not include the centromere (and so is paracentric) has been snipped out of a chromosome, turned through 180 degrees (inverted), and inserted right back into its original location in chromosome. The featu...
Chromosome inversion, pericentric
Chromosome inversion, pericentric: A basic type of chromosome rearrangement in which a segment that includes the centromere (and so is pericentric) has been snipped out of a chromosome, turned through 180 degrees (inverted), and inserted back into its original
location in chromosome. The feature tha...
Chromosome map: The chart of the linear array of genes on a chromosome.
A chromosome map can also refer to the visual appearance of a chromosome when stained and examined under a microscope. Particularly important are visually distinct regions, called light and dark bands, which give each of the chr...
A fragment of a chromosome (one of the microscopically visible carriers of the genetic material DNA) that is lacking a centromere (the "waist" of the chromosome essential for the division and the retention of the chromosome in the cell) and so is lost when the cell divides....
Chromosome, acrocentric: A
chromosome (one of the microscopically visible carriers of
the genetic material DNA) with its centromere (the "waist"
of the chromosome) located quite near one end of the
chromosome. The "acro-" in acrocentric comes from the Greek
"akron" meaning "the end." Humans ...
An abnormal chromosome (a microscopically visible carrier of the genetic material DNA) with two centromeres rather than the normal one. The centromere is essential for the division of the chromosome. A dicentric chromosome is twice tethered and so is pulled in opposite direct...
Chromosome, marker: An abnormal chromosome that is distinctive in appearance but not fully identified.
A marker chromosome is not a "marker" of a specific disease. It is a marker chromosome merely in the sense that it can be distinguished under the microscope from all of the normal human chromosomes...
Chromosome, metaphase: A chromosome in the stage of the
cell cycle (the sequence of events in the life of a cell) when a chromosome is most condensed and easiest to distinguish and so to study.
Metaphase chromosomes are often chosen for karyotyping and for chromosome analysis because they are read...