Mosaic Mongolism

Richards, B. W.

doi:10.1111/j.1365-2788.1969.tb01067.x

Cited by 20 publications

(13 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Clarke and coworkers (1961) first described mosaicism in Down's syndrome in a female infant who had some features of Down's syndrome and two cell lines, one normal and the other trisomic for a small acrocentric chromosome. Richards (1969) estimated the incidence of mosaicism in Down's syndrome at about 2 %. Mosaicism with a normal cell line is the type most often found in Down's syndrome.…”

Section: Discussionmentioning

confidence: 99%

“…In the different reports the proportion of trisomic cells in the total cell sample varies considerably (Mikkelsen 1971). Generally, fibroblast cultures have shown a higher proportion of trisomic cells than blood cultures, a finding which suggests a selection against trisomic cells in rapidly dividing tissues such as bone marrow (Richards 1969). Occasionally, the blood has had no trisomic cells, and a fibroblast culture (skin) was predominantly trisomic (Ridler et al 1965, Mikkelsen 1971.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Decreasing mosaicism in Down's syndrome

1980

View full text Add to dashboard Cite

A girl with trisomy‐21/normal mosaicism has been abserved for approximately 10 years. Her appearance is reminiscent of, but not typical for Down's syndrome, and her intellectual abilities are impaired but not to the same severe degree expected in Down's syndrome. These observations are consistent with the belief that, in persons ascertained by clinical resemblance to Down's syndrome, mosaicism with a normal cell line may dilute the typical appearance of Down's syndrome. The cytogenetic studies performed longitudinally demonstrated a significant decrease in the proportion of blood lymphocytes showing the trisornic line. The maximal decrease occurred in the first year of life. A direct preparation from the bone marrow and a fibroblast culture at 2.5 months showed 3 and 4 % trisomic cells, respectively, corresponding to the level of trisomic cells from the blood cultures during the second year of life.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Decreasing mosaicism in Down's syndrome

1980

View full text Add to dashboard Cite

show abstract

“…Another argument favoring the “aneuploidy dosage” hypothesis is based on the fact that Down's syndrome individuals with distinct levels of trisomic 21 cells vary from normal development (Verresen et al, 1964; Kohn et al, 1970) to mild (Ringman et al, 2008) or severe developmental delay (Richards, 1969). This indicates that frequency and type of aneuploidy might dictate whether a tissue will stay healthy or become diseased.…”

Section: Aneuploidy In Mental Disordersmentioning

confidence: 99%

Implications of aneuploidy for stem cell biology and brain therapeutics

Devalle¹,

Sartore²,

Paulsen³

et al. 2012

Front. Cell. Neurosci.

View full text Add to dashboard Cite

Understanding the cellular basis of neurological disorders have advanced at a slow pace, especially due to the extreme invasiveness of brain biopsying and limitations of cell lines and animal models that have been used. Since the derivation of pluripotent stem cells (PSCs), a novel source of cells for regenerative medicine and disease modeling has become available, holding great potential for the neurology field. However, safety for therapy and accurateness for modeling have been a matter of intense debate, considering that genomic instability, including the gain and loss of chromosomes (aneuploidy), has been repeatedly observed in those cells. Despite the fact that recent reports have described some degree of aneuploidy as being normal during neuronal differentiation and present in healthy human brains, this phenomenon is particularly controversial since it has traditionally been associated with cancer and disabling syndromes. It is therefore necessary to appreciate, to which extent, aneuploid pluripotent stem cells are suitable for regenerative medicine and neurological modeling and also the limits that separate constitutive from disease-related aneuploidy. In this review, recent findings regarding chromosomal instability in PSCs and within the brain will be discussed.

show abstract

“…Two to four percent of individuals with Down syndrome have a trisomic dose of the long arm of chromosome 21 as a result of a structural chromosomal abnormality (translocation or isochromosome) [Pangalos et al, 1994]. Mosaicism is seen in another two to four percent of individuals diagnosed with Down syndrome [Hamerton et al, 1965; Richards, 1969; Mikkelsen, 1977; Hook, 1981]. Mosaicism is a condition in which an individual has two or more genetically distinct cell lines that develop from a single zygote [Nussbam et al, 2001].…”

Section: Introductionmentioning

confidence: 99%

The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues

Papavassiliou

York

Gursoy

et al. 2009

American J of Med Genetics Pt A

103

View full text Add to dashboard Cite

Little is known about the pathogenesis of the phenotype in individuals with trisomy 21 mosaicism and Down syndrome. The primary goal of this study was to identify factors contributing to the observed phenotypic variation by evaluating 107 individuals having trisomy 21 mosaicism. To investigate a potential “threshold” effect due to trisomic imbalance, lymphocyte and buccal mucosa nuclei were scored using FISH. Overall, buccal cells showed a significantly higher frequency of trisomy than lymphocytes (P< 0.0001). Using latent class analysis, two phenotypic classes were identified based on the clinical findings of the propositi. Patients from class 1 had significantly fewer traits and a lower percentage of trisomic cells (mean of 37.3% lymphocytes; 34.5% buccal mucosa cells) when compared to those stratified into class 2 (54.0% lymphocytes; 53.4% buccal mucosa cells). Tissue-specific influences were also detected, with buccal mucosa trisomy levels being significantly correlated with IQ (P = 0.0094; both ectodermal derivatives), while congenital heart defects were significantly correlated with lymphocytes (P = 0.0286; both mesodermal embryonic derivatives). In conclusion, allowing for the distinction of two groups, we observed variation in phenotype, associated with the percentage of trisomic cells. We also observed tissue-specific effects on phenotype. The results of this study should enable geneticists and other health care professionals to provide information regarding optimal diagnostic approaches and anticipated clinical outcomes.

show abstract

Mosaic Mongolism

Cited by 20 publications

References 22 publications

Decreasing mosaicism in Down's syndrome

Decreasing mosaicism in Down's syndrome

Implications of aneuploidy for stem cell biology and brain therapeutics

The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues

Contact Info

Product

Resources

About