scholarly journals A Cytogenetic Study in 120 Turkish Children with Intellectual Disability and Characteristics of Fragile X Syndrome

2003 ◽  
Vol 44 (4) ◽  
pp. 583 ◽  
Author(s):  
Osman Demirhan ◽  
Deniz Tastemir ◽  
Rasim Somer Diler ◽  
Sunay Firat ◽  
Ayse Avci
Keyword(s):  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Cytogenetic Study ◽  
Turkish Children ◽  
Children With Intellectual Disability

scholarly journals Blood spots screening for identification of Fragile X Syndrome among intellectual disability students in Flores Island, INDONESIA

2013 ◽  
Vol 2013 (S1) ◽  
Author(s):  
Agustini Utari ◽  
Joyce Lo ◽  
Tzuhan Tong ◽  
Tri Indah Winarni ◽  
Sultana MH Faradz ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Blood Spots

Validation of Hagerman’s behavioral phenotype for fragile X syndrome among men with intellectual disability

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jacques Bellavance ◽  
Morin Diane ◽  
Catherine Mello
Keyword(s):  
Down Syndrome ◽  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Design Methodology ◽  
Fragile X ◽  
Behavioral Phenotype ◽  
Care Providers ◽  
Content Type

Purpose The behavioral phenotype of fragile X syndrome (FXS) and intellectual disability (ID) proposed by Hagerman et al. (2009) was primarily based on data from male children and teens. The purpose of this study was to promote a better understanding of how this condition manifests in adults. Design/methodology/approach A total of 18 men of FXS were paired with men with Down syndrome on the basis of age and level of ID. A screening checklist was created on the basis of existing scales and the Hagerman et al. (2009) behavioral phenotype and completed by care providers. Findings Five of the 12 features of the phenotype were significantly more present among men with FXS than in men with Down syndrome. Originality/value This study provides partial confirmation for Hagerman et al.’s (2009) behavioral phenotype of FXS among men with moderate ID and identified some traits that warrant further investigation.

Fragile X: A Family of Disorders

2010 ◽  
Author(s):  
Ann M. Mastergeorge ◽  
Jacky Au
Keyword(s):  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
X Chromosome ◽  
Culture Media ◽  
Fragile Site ◽  
Fragile X ◽  
Single Gene ◽  
Repeat Sequence ◽  
Full Mutation ◽  
Tissue Culture Media

Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability known, and it is the most common single gene disorder associated with autism (Belmonte and Bourgeron 2006; Reddy 2005). It is caused by the lack or deficiency of the FMR1 protein, FMRP (Loesch et al. 2004b). The typical physical features of FXS include prominent ears, hyperextensible finger joints, flat feet, soft skin, and in adolescence and adulthood large testicles (macroorchidism) and a long face (Hagerman 2002b). The behavioral features include poor eye contact, hyperarousal to stimuli, anxiety, hyperactivity, attention deficit, impulsivity, hand stereotypies (such as hand biting and hand flapping), and social deficits including autism and autism spectrum disorder (ASD) (Budimirovic et al. 2006; Clifford et al. 2007; Hall et al. 2008b; Hatton et al. 2006b; Sullivan et al. 2007b). Fragile-X syndrome was first reported by Lubs (1969) in two brothers who had intellectual disability and the appearance of a marker X chromosome, which is a fragile site on their X chromosome. It was later detected that this fragile site on the X chromosome only occurred when the chromosomes were studied in a folate-deficient tissue culture media (Sutherland 1977). Therefore cytogenetic studies were utilized to document cases of FXS throughout the 1980s until the Fragile X Mental Retardation 1 gene (FMR1) was discovered in 1991 (Verkerk et al. 1991). The FMR1 gene was found to have a trinucleotide (CGG) repeat sequence at the 5’ untranslated region, with the normal range later determined to be up to 44 repeats, a gray zone of 45–54 repeats, a premutation of 55–200 repeats, and a full mutation range of more than 200 repeats (Maddalena et al. 2001). Those individuals with the full mutation have a deficit or absence of the FMR1 protein (FMRP) that causes the physical, behavioral, and cognitive features of FXS (Loesch et al. 2004b). Females with the full mutation have another X chromosome that is producing FMRP, depending on the activation ratio (AR) or the percentage of cells that have the normal X chromosome as the active X chromosome.

scholarly journals Towards Mechanism-Based Treatments for Fragile X Syndrome

2019 ◽  
Vol 9 (8) ◽  
pp. 202
Author(s):  
Daman Kumari ◽  
Inbal Gazy
Keyword(s):  
Autism Spectrum Disorder ◽  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Autism Spectrum ◽  
Spectrum Disorder

Fragile X syndrome (FXS) is the most common heritable form of intellectual disability, as well as the most common known monogenic cause of autism spectrum disorder (ASD), affecting 1 in 4000–8000 people worldwide [...]

scholarly journals Single-Nucleotide Mutations in FMR1 Reveal Novel Functions and Regulatory Mechanisms of the Fragile X Syndrome Protein FMRP

2015 ◽  
Vol 9s2 ◽  
pp. JEN.S25524 ◽  
Author(s):  
Joshua A. Suhl ◽  
Stephen T. Warren
Keyword(s):  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Point Mutations ◽  
Regulatory Mechanisms ◽  
Cgg Repeat ◽  
Novel Variants ◽  
Sequencing Studies ◽  
The Cost ◽  
Syndrome Protein

Fragile X syndrome is a monogenic disorder and a common cause of intellectual disability. Despite nearly 25 years of research on FMR1, the gene underlying the syndrome, very few pathological mutations other than the typical CGG-repeat expansion have been reported. This is in contrast to other X-linked, monogenic, intellectual disability disorders, such as Rett syndrome, where many point mutations have been validated as causative of the disorder. As technology has improved and significantly driven down the cost of sequencing, allowing for whole genes to be sequenced with relative ease, in-depth sequencing studies on FMR1 have recently been performed. These studies have led to the identification of novel variants in FMR1, where some of which have been functionally evaluated and are likely pathogenic. In this review, we discuss recently identified FMR1 variants, the ways these novel variants cause dysfunction, and how they reveal new regulatory mechanisms and functionalities of the gene.

scholarly journals The fragile-X syndrome: a growing gene causing familial intellectual disability

2008 ◽  
Vol 38 (1) ◽  
pp. 1-8 ◽  
Author(s):  
L. B. A. VRIES ◽  
D. J. J. HAULEY ◽  
B. A. OOSTRA ◽  
M. F. NIERMEIJER
Keyword(s):  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Fragile X
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