Fragile-X syndrome and skewed X-chromosome inactivation within a family: A female member with complete inactivation of the functional X chromosome

2003 ◽  
Vol 122A (2) ◽  
pp. 108-114 ◽  
Author(s):  
D. Heine-Suñer ◽  
L. Torres-Juan ◽  
M. Morlà ◽  
X. Busquets ◽  
F. Barceló ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
X Chromosome ◽  
Fragile X ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Complete Inactivation ◽  
Female Member ◽  
Skewed X Chromosome Inactivation

scholarly journals Detection of skewed X-chromosome inactivation in Fragile X syndrome and X chromosome aneuploidy using quantitative melt analysis

2015 ◽  
Vol 17 ◽  
Author(s):  
David E. Godler ◽  
Yoshimi Inaba ◽  
Charles E. Schwartz ◽  
Quang M. Bui ◽  
Elva Z. Shi ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
X Chromosome ◽  
Sex Chromosome ◽  
Fragile X ◽  
Venous Blood ◽  
Reference Method ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
X Chromosomes ◽  
Skewed X Chromosome Inactivation

Methylation of the fragile X mental retardation 1 (FMR1) exon 1/intron 1 boundary positioned fragile X related epigenetic element 2 (FREE2), reveals skewed X-chromosome inactivation (XCI) in fragile X syndrome full mutation (FM: CGG > 200) females. XCI skewing has been also linked to abnormal X-linked gene expression with the broader clinical impact for sex chromosome aneuploidies (SCAs). In this study, 10 FREE2 CpG sites were targeted using methylation specific quantitative melt analysis (MS-QMA), including 3 sites that could not be analysed with previously used EpiTYPER system. The method was applied for detection of skewed XCI in FM females and in different types of SCA. We tested venous blood and saliva DNA collected from 107 controls (CGG < 40), and 148 FM and 90 SCA individuals. MS-QMA identified: (i) most SCAs if combined with a Y chromosome test; (ii) locus-specific XCI skewing towards the hypomethylated state in FM females; and (iii) skewed XCI towards the hypermethylated state in SCA with 3 or more X chromosomes, and in 5% of the 47,XXY individuals. MS-QMA output also showed significant correlation with the EpiTYPER reference method in FM males and females (P < 0.0001) and SCAs (P < 0.05). In conclusion, we demonstrate use of MS-QMA to quantify skewed XCI in two applications with diagnostic utility.

Unusual X chromosome inactivation in a mentally retarded girl with an interstitial deletion Xq27: implications for the fragile X syndrome

1990 ◽  
Vol 84 (4) ◽  
pp. 347-352 ◽  
Author(s):  
Malgorzata Schmidt ◽  
Andrea Certoma ◽  
Desirée Du Sart ◽  
Paul Kalitsis ◽  
Margaret Leversha ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
X Chromosome ◽  
Fragile X ◽  
Mentally Retarded ◽  
X Chromosome Inactivation ◽  
Interstitial Deletion ◽  
Chromosome Inactivation

scholarly journals A brain network basis of Fragile X syndrome behavioral penetrance determined by X chromosome inactivation in female mice

2018 ◽  
Author(s):  
Eric Szelenyi ◽  
Danielle Fisenne ◽  
Joseph E Knox ◽  
Julie A Harris ◽  
James A Gornet ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Cell Density ◽  
X Chromosome ◽  
Fragile X ◽  
Mutant Cell ◽  
Autism Spectrum ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Entry Points ◽  
Parent Of Origin

ABSTRACTX-chromosome inactivation (XCI) in females is vital for normal brain function and cognition, as many X-linked genetic mutations lead to mental retardation and autism spectrum disorders, such as the fragile X syndrome (FXS). However, the degree by which XCI regulates disease presentation has been poorly investigated. To study this regulation in the mouse, here we quantified the brainwide composition of active-XC cells at single cell resolution using an X-linked MECP2-EGFP allele with known parent-of-origin. We present evidence that whole-brains, including all regions, on average favor maternal XC-active cells by 20%, or 8 million cells. This bias was conserved in heterozygous FXS mutant mice, which also corresponded to disease penetrance in maternal but not paternal FMR1 null mice. To localize the physical source of behavioral penetrance, brain-wide correlational screens successfully mapped mouse performance to cell densities in putative sensorimotor (e.g. sensory hindbrain, thalamus, globus pallidus) and sociability (e.g. visual/entorhinal cortices, bed nucleus stria terminalis, medial preoptic area) behavioral circuits of the open field sensorimotor and 3-chamber sociability assays, respectively. Overall, 50%/50% healthy/mutant cell density ratios in these sub-networks were required for disease presentation in each behavior. These results suggest female X-linked behavioral penetrance of disease is regulated at the distributed level of mutant cell density in behavioral circuits, which is set by XCI that is subject to parent-of-origin effects. This work provides a novel finding behind the broad and varied behavioral phenotypes commonly featured in female patients debilitated by X-linked mental disorders and may offer new entry points for behavioral therapeutics.

X-linked CNV and skewed X-chromosome inactivation

2020 ◽  
pp. 19-21
Author(s):  
Е.А. Фонова ◽  
Е.Н. Толмачева ◽  
А.А. Кашеварова ◽  
М.Е. Лопаткина ◽  
К.А. Павлова ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Intellectual Disability ◽  
X Chromosome ◽  
Copy Number ◽  
Copy Number Variations ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Chromosome X ◽  
Skewed X Chromosome Inactivation

Смещение инактивации Х-хромосомы может быть следствием и маркером нарушения клеточной пролиферации при вариациях числа копий ДНК на Х-хромосоме. Х-сцепленные CNV выявляются как у женщин с невынашиванием беременности и смещением инактивации Х-хромосомы (с частотой 33,3%), так и у пациентов с умственной отсталостью и смещением инактивацией у их матерей (с частотой 40%). A skewed X-chromosome inactivation can be a consequence and a marker of impaired cell proliferation in the presence of copy number variations (CNV) on the X chromosome. X-linked CNVs are detected in women with miscarriages and a skewed X-chromosome inactivation (with a frequency of 33.3%), as well as in patients with intellectual disability and skewed X-chromosome inactivation in their mothers (with a frequency of 40%).

scholarly journals Skewed X-Chromosome Inactivation Is a Common Feature of X-Linked Mental Retardation Disorders

2002 ◽  
Vol 71 (1) ◽  
pp. 168-173 ◽  
Author(s):  
Robert M. Plenge ◽  
Roger A. Stevenson ◽  
Herbert A. Lubs ◽  
Charles E. Schwartz ◽  
Huntington F. Willard
Keyword(s):  
Mental Retardation ◽  
X Chromosome ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Skewed X Chromosome Inactivation

scholarly journals Extremely skewed X-chromosome inactivation is increased in pre-eclampsia

2006 ◽  
Vol 121 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Elif Uz ◽  
Ismail Dolen ◽  
Atakan R. Al ◽  
Tayfun Ozcelik
Keyword(s):  
X Chromosome ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Skewed X Chromosome Inactivation

Skewed X-chromosome inactivation plays a crucial role in the onset of symptoms in carriers of Becker muscular dystrophy

2017 ◽  
Vol 19 (4) ◽  
pp. e2952 ◽  
Author(s):  
Emanuela Viggiano ◽  
Esther Picillo ◽  
Manuela Ergoli ◽  
Alessandra Cirillo ◽  
Stefania Del Gaudio ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
X Chromosome ◽  
Crucial Role ◽  
Becker Muscular Dystrophy ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Skewed X Chromosome Inactivation

scholarly journals Persistence of skewed X-chromosome inactivation in pre-B acute lymphoblastic leukemia of a female ATRX mutation carrier

2019 ◽  
Vol 3 (17) ◽  
pp. 2627-2631
Author(s):  
Christian P. Bradley ◽  
Cai Chen ◽  
Karolyn A. Oetjen ◽  
Cheng Yan ◽  
Reema Panjwani ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
X Chromosome ◽  
Germline Mutation ◽  
Mutation Carrier ◽  
Lymphoblastic Leukemia ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Female Carrier ◽  
Key Points ◽  
Skewed X Chromosome Inactivation

Key Points Leukemic blasts of a female carrier of an ATRX germline mutation have persistently skewed inactivation of the X chromosome. Germline mutation in leukemia needs to be interpreted with caution because it is not always pathologic.

Skewed X-chromosome inactivation in human embryos with mosaic trisomy 16

2011 ◽  
Vol 47 (3) ◽  
pp. 354-357 ◽  
Author(s):  
E. N. Tolmacheva ◽  
A. A. Kashevarova ◽  
N. N. Sukhanova ◽  
V. N. Kharkov ◽  
I. N. Lebedev
Keyword(s):  
X Chromosome ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Human Embryos ◽  
Trisomy 16 ◽  
Skewed X Chromosome Inactivation ◽  
Mosaic Trisomy
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