aneuploidy


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Related to aneuploidy: aneuploidy screening, Turner syndrome

aneuploidy

 [an″u-ploi´de]
the state of having chromosomes in a number that is not an exact multiple of the haploid number. adj., adj an´euploid.

an·eu·ploi·d·y

(an'yū-ploy'dē),
State of being aneuploid.

aneuploidy

/an·eu·ploi·dy/ (an″u-ploi´de) any deviation from an exact multiple of the haploid number of chromosomes, whether fewer or more.

aneuploidy

[an′yoo͡ploi′dē]
any variation in chromosome number that involves individual chromosomes rather than entire sets of chromosomes. There may be fewer chromosomes, as in Turner's syndrome (one X chromosome in females), or more chromosomes, as in Down syndrome (three copies of chromosome 21). Such individuals have various abnormal physiological and morphological traits. Compare euploidy. See also chromosomal aberration, monosomy, trisomy.

an·eu·ploi·d·y

(an'yū-ploy'dē)
State of being aneuploid.

aneuploidy

An abnormality in the number of CHROMOSOMES by loss or duplication. The number may be smaller or greater than the normal diploid constitution. The loss of a whole chromosome is lethal. A chromosome extra to one of the pairs is called TRISOMY. Trisomy 21, for instance, causes DOWN'S SYNDROME. DNA aneuploidy refers to abnormal quantities of DNA in a nucleus. See also MOSAICISM.

aneuploidy

a condition where more or less than a complete set of chromosomes is found in each cell of an individual. Compare EUPLOIDY. Typically aneuploids have one extra or one missing chromosome. For example, in DOWN'S SYNDROME affected individuals have three number-21 chromosomes rather than the normal two, a condition known as TRISOMY. see CHROMOSOMAL MUTATION.

chromosome 

One of the thread-like structures located within the cell nucleus composed of an extremely long, double-stranded DNA (deoxyribonucleic acid) helix tightly folded around proteins called histones. Each chromosome carries genes that contain the hereditary material that controls the growth and characteristics of the body. There are 46 chromosomes in each human somatic cell organized in 23 pairs, of which 22 pairs are similar in appearance but differ at the molecular level. They are called autosomal chromosomes or autosomes and are designated by a number (with chromosome 1 being the longest, followed by chromosome 2, etc.). The other pair, the sex chromosomes determines the sex of the individual. In mammals the two sex chromosomes of females are alike (homologous) and are referred to as X chromosomes. Males carry one X chromosome along with a much shorter chromosome, the Y chromosome. Each chromosome has a centromere that divides it into two arms, the short arm 'p' and the long arm 'q'. Disorders of chromosome number in which the number of chromosomes is above or below the normal (46) are called aneuploidy. Common forms of aneuploidy are trisomy in which there is one extra chromosome and monosomy in which there is one less, than the normal 46. They rarely cause specific eye diseases but affected individuals present ocular manifestations. Examples: Down's syndrome (trisomy of chromosome 21), Edwards' syndrome (trisomy 18), Turner's syndrome (monosomy 45 XO). There are other chromosome abnormalities such as translocation (one segment of a chromosome is transferred to another chromosome) as may occur in congenital anterior polar cataract, deletion (a loss of a piece of chromosome) as in aniridia, choroideremia, retinoblastoma, etc. Other cases involve damage of a chromosome (e.g. fragile X syndrome). See defective colour vision; gene; mitosis; mutation.

aneuploidy

the state of having chromosomes in a number that is not an exact multiple of the haploid number; seen in karyotypes which have a small number of extra chromosomes or have a small number less than normal.
References in periodicals archive ?
Aneuploidy rates skyrocketed in mice exposed to the BPA-laden plastic compared with those of the control mice, the team reports in the April 1 Current Biology.
In 206 SA cases, complete or partial aneuploidy was detected involving trisomy (85.
We support national guidelines and the recent American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine Committee Opinion recommending cell-free DNA prenatal testing is one option that can be used as a primary or secondary screening test in women at increased risk of aneuploidy.
Not only can there be false-positive test results, but a positive cell-free DNA test result for aneuploidy does not determine if the trisomy is due to a translocation, which affects the risk of recurrence.
We recently reported a discordant NIPT case of trisomy 18 due to 6% maternal mosaicism for this aneuploidy (15), thus demonstrating in principle that an altered maternal-DNA plasma can substantially skew the final fetal z score for the involved chromosome.
51) This method differs from the targeted sequencing approach in that it specifically targets SNPs instead of non-polymorphic regions and uses a genotype-based analytic method rather than a counting approach to detect fetal aneuploidy.
Boveri pointed out that his aneuploidy theory explains the increasing risk of cancer with age because in aging cells, division is more frequently disturbed.
Multicolor sperm FISH was employed to determine the frequency of sperm aneuploidy for chromosomes X, Y, or 21 (Baumgartner et al.
Combined first- and second-trimester screening for aneuploidy
Further, all of our single gene embryos receive comprehensive chromosomal aneuploidy screening in tandem to single gene disorder diagnosis, using a single biopsy.
The fact that most lab reports based on the testing will state either that aneuploidy is present or is not present contributed to the sense that the testing was diagnostic, and therefore to misinterpretation of results, said Dr.
Two assays are available, Prenatal BoBs[TM] for the detection of trisomy 13, 18, and 21 and the most frequent syndromes associated with microdeletions, and KaryoLite BoBs[TM], which can detect aneuploidy in all chromosomes by quantifying the proximal and terminal regions of each chromosome arm.