monosomy


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Related to monosomy: terminal deletion, Partial monosomy

monosomy

 [mon″o-so´me]
existence in a cell of only one instead of the normal diploid pair of a particular chromosome, seen in Turner's syndrome,monosomy 9p disease, and various other conditions. adj., adj monoso´mic.
monosomy 9p syndrome a rare chromosomal disorder in which a piece of the short arm of the ninth chromosome is broken and often lost. Symptoms include mental retardation, a triangular head with forward angulation of the frontal bone, and various other physical deformities. A support group for more information on this syndrome can be reached at 43304 Kipton Nickel Plate Road, La Grange, OH 44050.

mon·o·so·my

(mon'ō-sō'mē),
Absence of one chromosome of a pair of homologous chromosomes.
See also: chromosomal deletion.
[see monosome]

monosomy

/mono·so·my/ (mon´o-so″me) existence in a cell of only one instead of the normal diploid pair of a particular chromosome.monoso´mic

monosomy

[mon′əsō′mē]
Etymology: Gk, monos + soma, body
a chromosomal aberration characterized by the absence of one chromosome from the normal diploid complement. In humans the monosomic cell contains 45 chromosomes and is designated 2n N 1, such as occurs in the XO condition in Turner's syndrome. Compare trisomy. See also aneuploidy. monosomic, adj.

monosomy

(1) A type of aneuploidy, defined by the formula 2n – 1, where n is the haploid number. (E.g., Turner syndrome or monosomy X.)
(2) The state of having a single chromosome of a particular type; lacking a homologous chromosome (e.g., normal males are monosomic for the X chromosome).

monosomy

Genetics A type of aneuploidy defined by the formula 2n – 1, where n is the haploid number–eg, Turner syndrome or monosomy X. See Aneuploidy.

mon·o·so·my

(mon'ō-sō'mē)
Absence of one chromosome of a pair of homologous chromosomes.

monosomy

The absence of one complete AUTOSOMAL chromosome of a pair. This is a lethal condition. Compare TRISOMY as in DOWN'S SYNDROME.

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.

monosomy

existence in a cell of only one instead of the normal diploid pair of a particular chromosome.
References in periodicals archive ?
Reported "no-call" rates for counting methods specifically excluded Monosomy X from the analysis, resulting in no-call rates from 0.
Monosomy lp36 a recently delineated, clinically recognizable syndrome.
Increasing this analysis to 70 blood lymphocyte metaphases identified a low level of mosaicism with two cells showing a loss of the ring 9 (resulting in monosomy for chromosome 9), one cell with a broken ring 9, and one cell with a double ring resulting in trisomy for chromosome 9 (Figure 2).
Cytogenetic analysis indicated that up to 35% of small melanomas are positive for monosomy 3 proving that tumour size, though clinically important in predicting metastatic potential, does not exclude malignant behaviour.
The more common transgressions of chromosomal disorders express either a chromosomal excess, such as with Trisomy 21/Down Syndrome, or they express a chromosomal defect/ deficiency, such as with monosomy aneuploidy or the partial trisomy of Wolf-Hirschhorn Syndrome (a condition expressing severe growth retardation, microcephaly, and congenital heart defects).
Pietro Invernizzi of the University of Milan and his colleagues prospectively looked for the presence of X chromosome monosomy in the blood of 100 women with primary biliary cirrhosis (PBC), 50 women with chronic hepatitis C infection, and 50 healthy women.
Fluorescence in situ hybridization (FISH) using polymerase chain reaction (PCR) techniques showed no evidence for monosomy, trisomy 8, or partial deletions of the long arm of chromosome 5 or 7.
He has a missing part on one side called a monosomy and an extra part on the other called a trisomy.
Natera, a leading innovator in reproductive and prenatal genetic testing, today announced that the company's non-invasive prenatal screening test, Panorama[TM], will launch on March 1 for the detection of trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), trisomy 13 (Patau syndrome) and select sex chromosome abnormalities, such as monosomy X (Turner's syndrome).
Panorama uses a simple blood draw from the mother to examine cell-free DNA found in maternal blood originating from both mother and fetus to screen for chromosome abnormalities, including trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), trisomy 13 (Patau syndrome), monosomy X (Turner syndrome), and triploidy.
The toddler was diagnosed with rare blood disorder Monosomy 7 Syndrome last June, sparking a worldwide search for a donor before he developed leukaemia.