X-inactivation pattern in carriers of X-linked retinitis pigmentosa: A valuable means of prognostic evaluation?

1993 ◽  
Vol 92 (4) ◽  
pp. 359-363 ◽  
Author(s):  
Ursula Friedrich ◽  
Mette Warburg ◽  
Arne Lund J�rgensen
Keyword(s):  
Retinitis Pigmentosa ◽  
X Inactivation ◽  
Prognostic Evaluation ◽  
Inactivation Pattern

scholarly journals Rare Co-Occurrence of Visual Snow in a Female Carrier With RPGRORF15-Associated Retinal Disorder

2021 ◽  
Vol 12 ◽  
Author(s):  
Aekkachai Tuekprakhon ◽  
Aulia Rahmi Pawestri ◽  
Ragkit Suvannaboon ◽  
Ketwarin Thongyou ◽  
Adisak Trinavarat ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Disease Onset ◽  
Retinal Dystrophy ◽  
Female Carrier ◽  
Ophthalmological Examination ◽  
Early Disease ◽  
Rare Form ◽  
Inactivation Pattern ◽  
Retinal Disorder ◽  
Female Carriers

X-linked retinitis pigmentosa (XLRP), a rare form of retinitis pigmentosa (RP), is predominantly caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene. Affected males often present with severe phenotypes and early disease onset. In contrast, female carriers are usually asymptomatic or show stationary phenotypes. Herein, we reported an 8-year-old female carrier, a daughter of a confirmed RP father with RPGR mutation, with an early onset of progressive cone-rod pattern retinal dystrophy. Additionally, the carrier experienced visual snow-like symptom as long as she recalled. Ophthalmological examination showed the reduction of visual acuity and attenuation of photoreceptor functions since the age of 5 years. Further analysis revealed a heterozygous pathogenic variant of the RPGR gene and a random X-inactivation pattern. Although she harboured an identical RPGR variant as the father, there were phenotypic intrafamilial variations. The information on the variety of genotypic and phenotypic presentations in XLRP carriers is essential for further diagnosis, management, and monitoring of these cases, including the design of future gene therapy trials.

X-inactivation pattern in the liver of a manifesting female with ornithine transcarbamylase (OTC) deficiency

1998 ◽  
Vol 54 (4) ◽  
pp. 349-353 ◽  
Author(s):  
Tohru Yorifuji ◽  
Junko Muroi ◽  
Ayumi Uematsu ◽  
Koichi Tanaka ◽  
Koji Kiwaki ◽  
...  
Keyword(s):  
Ornithine Transcarbamylase ◽  
X Inactivation ◽  
Inactivation Pattern ◽  
Otc Deficiency

scholarly journals Exploring the Variable Phenotypes of RPGR Carrier Females in Assessing their Potential for Retinal Gene Therapy

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 643 ◽  
Author(s):  
Anika Nanda ◽  
Anna P. Salvetti ◽  
Penny Clouston ◽  
Susan M. Downes ◽  
Robert E. MacLaren
Keyword(s):  
Gene Therapy ◽  
Retinitis Pigmentosa ◽  
Phenotypic Variability ◽  
Genetic Mutation ◽  
X Inactivation ◽  
Autofluorescence Imaging ◽  
Genetic Sequencing ◽  
Pigmentary Retinopathy ◽  
Retinal Degenerations ◽  
Female Carriers

Inherited retinal degenerations are the leading cause of blindness in the working population. X-linked retinitis pigmentosa (XLRP), caused by mutations in the Retinitis pigmentosa GTPase regulator (RPGR) gene is one of the more severe forms, and female carriers of RPGR mutations have a variable presentation. A retrospective review of twenty-three female RPGR carriers aged between 8 and 76 years old was carried out using fundoscopy, autofluorescence imaging (AF), blue reflectance (BR) imaging and optical coherence tomography (OCT). Confirmation of the genetic mutation was obtained from male relatives or Sanger genetic sequencing. Fundus examination and AF demonstrate phenotypic variability in RPGR carriers. The genetic mutation appears indeterminate of the degree of change. We found four distinct classifications based on AF images to describe RPGR carriers; normal (N) representing normal or near-normal AF appearance (n = 1, 4%); radial (R) pattern reflex without pigmentary retinopathy (n = 14, 61%); focal (F) pigmentary retinopathy (n = 5, 22%) and; male (M) phenotype (n = 3, 13%). The phenotypes were precisely correlated in both eyes (rs = 1.0, p < 0.0001). Skewed X-inactivation can result in severely affected carrier females—in some cases indistinguishable from the male pattern and these patients should be considered for RPGR gene therapy. In the cases of the male (M) phenotype where the X-inactivation was skewed, the pattern was similar in both eyes, suggesting that the mechanism is not truly random but may have an underlying genetic basis.

scholarly journals Incorporation of 5-ethynyl-2′-deoxyuridine (EdU) as a novel strategy for identification of the skewed X inactivation pattern in balanced and unbalanced X-rearrangements

2015 ◽  
Vol 135 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Luiza Sisdelli ◽  
Angela Cristina Vidi ◽  
Mariana Moysés-Oliveira ◽  
Adriana Di Battista ◽  
Adriana Bortolai ◽  
...  
Keyword(s):  
X Inactivation ◽  
Inactivation Pattern ◽  
Novel Strategy ◽  
Skewed X Inactivation

scholarly journals Intelligence Quotient Variability in Klinefelter Syndrome Is Associated With GTPBP6 Expression Under Regulation of X-Chromosome Inactivation Pattern

2021 ◽  
Vol 12 ◽  
Author(s):  
Luciane Simonetti ◽  
Lucas G. A. Ferreira ◽  
Angela Cristina Vidi ◽  
Janaina Sena de Souza ◽  
Ilda S. Kunii ◽  
...  
Keyword(s):  
Gene Expression ◽  
X Chromosome ◽  
Intelligence Quotient ◽  
Klinefelter Syndrome ◽  
X Chromosome Inactivation ◽  
X Inactivation ◽  
Chromosome Inactivation ◽  
Neurocognitive Dysfunction ◽  
Inactivation Pattern ◽  
Iq Scores

Klinefelter syndrome (KS) displays a broad dysmorphological, endocrinological, and neuropsychological clinical spectrum. We hypothesized that the neurocognitive dysfunction present in KS relies on an imbalance in X-chromosome gene expression. Thus, the X-chromosome inactivation (XCI) pattern and neurocognitive X-linked gene expression were tested and correlated with intelligence quotient (IQ) scores. We evaluated 11 KS patients by (a) IQ assessment, (b) analyzing the XCI patterns using both HUMARA and ZDHHC15 gene assays, and (c) blood RT-qPCR to investigate seven X-linked genes related to neurocognitive development (GTPBP6, EIF2S3, ITM2A, HUWE1, KDM5C, GDI1, and VAMP7) and XIST in comparison with 14 (male and female) controls. Considering IQ 80 as the standard minimum reference, we verified that the variability in IQ scores in KS patients seemed to be associated with the XCI pattern. Seven individuals in the KS group presented a random X-inactivation (RXI) and lower average IQ than the four individuals who presented a skewed X-inactivation (SXI) pattern. The evaluation of gene expression showed higher GTPBP6 expression in KS patients with RXI than in controls (p = 0.0059). Interestingly, the expression of GTPBP6 in KS patients with SXI did not differ from that observed in controls. Therefore, our data suggest for the first time that GTPBP6 expression is negatively associated with full-scale IQ under the regulation of the type of XCI pattern. The SXI pattern may regulate GTPBP6 expression, thereby dampening the impairment in cognitive performance and playing a role in intelligence variability in individuals with KS, which warrants further mechanistic investigations.

X-inactivation pattern in the epididymis of sex-reversed mice heterozygous for testicular feminization

Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 217-225
Author(s):  
Ulrich Drews ◽  
Valentin Alonso-Lozano
Keyword(s):  
X Chromosome ◽  
Sex Reversal ◽  
Cellular Level ◽  
X Inactivation ◽  
Testicular Feminization ◽  
Wild Type ◽  
Female Mice ◽  
Inactivation Pattern ◽  
Ultrastructural Appearance ◽  
Male Sex

Female mice heterozygous for testicular feminization were sex-reversed by means of the autosomal sex reversal mutation (Sxr). Due to X-inactivation, the blastemata for male sex organs in these animals are composed of a mixture of cells, carrying either the wildtype X chromosome or the X chromosome affected with Tfm in an active state. Thus, the two types of cells are sensitive to androgens or insensitive to androgens, respectively. This mosaic could be demonstrated in the epididymis on a cellular level. Segments of undifferentiated Tfm cells were found alternating with normally differentiated wild-type cells. The ultrastructural appearance of the mosaic is described.

Functional monosomy of 6q27-qter and functional disomy of Xpter-p22.11 due to X;6 translocation with an atypical X-inactivation pattern

2017 ◽  
Vol 173 (5) ◽  
pp. 1334-1341 ◽  
Author(s):  
Anna Podolska ◽  
Albrecht Kobelt ◽  
Sigrid Fuchs ◽  
Karl Hackmann ◽  
Andreas Rump ◽  
...  
Keyword(s):  
X Inactivation ◽  
Inactivation Pattern

X inactivation pattern in interstitial deletions of the fragile X region

1994 ◽  
Vol 51 (4) ◽  
pp. 451-451 ◽  
Author(s):  
Malgorzata Schmidt ◽  
Anne Robertson ◽  
Marjorie Crawford
Keyword(s):  
Fragile X ◽  
X Inactivation ◽  
Inactivation Pattern

De novo interstitial direct duplication of Xq21.1q25 associated with skewed X-inactivation pattern

2004 ◽  
Vol 131A (3) ◽  
pp. 273-280 ◽  
Author(s):  
G. Tachdjian ◽  
A. Aboura ◽  
M. Benkhalifa ◽  
I. Creveaux ◽  
L. Foix-Hélias ◽  
...  
Keyword(s):  
De Novo ◽  
X Inactivation ◽  
Inactivation Pattern ◽  
Skewed X Inactivation
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