PREVALENCE OF THE FRAGILE X SYNDROME IN YUGOSLAV PATIENTS WITH NON-SPECIFIC MENTAL RETARDATION

2003 ◽  
Vol 17 (2) ◽  
pp. 223-230
Author(s):  
Tamara Major ◽  
Biljana Culjkovic ◽  
Oliver Stojkovic ◽  
Marija Gucscekic ◽  
Aneta Lakic ◽  
...  
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Fragile X

Learning-disabled Males With a Fragile X CGG Expansion in the Upper Premutation Size Range

PEDIATRICS ◽  
1996 ◽  
Vol 97 (1) ◽  
pp. 122-126
Author(s):  
Randi J. Hagerman ◽  
Louise W. Staley ◽  
Rebecca O'Conner ◽  
Kellie Lugenbeel ◽  
David Nelson ◽  
...  
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Size Range ◽  
Cpg Island ◽  
Fragile X ◽  
Learning Disabled ◽  
Full Mutation ◽  
Cgg Repeat ◽  
Responsible Gene ◽  
Repeat Segment

There is a broad spectrum of clinical involvement in both boys and girls affected by fragile X syndrome. Although this disorder is best known as the most common inherited cause of mental retardation, it also can manifest as learning disabilities in individuals with IQs in the broad range of normal. Boys are usually retarded, and girls are usually learning disabled with fragile X syndrome.1 The responsible gene, fragile X mental retardation 1 (FMR1), was isolated in 1991, and the mutation was found to involve expansion of a trinucleotide (CGG) repeat segment. Individuals with fragile X syndrome have a CGG expansion of more than 200 repeats associated with hypermethylation of both the expansion and an adjacent CpG island (full mutation).2,3

Prevalence of fragile X syndrome among patients with mental retardation in the west of Iran

2018 ◽  
Vol 13 (6) ◽  
pp. 464-468 ◽  
Author(s):  
Peyman Hadi ◽  
Karimeh Haghani ◽  
Ali Noori-Zadeh ◽  
Salar Bakhtiyari
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
The West

scholarly journals Role of microRNA Pathway in Mental Retardation

2007 ◽  
Vol 7 ◽  
pp. 146-154 ◽  
Author(s):  
Abrar Qurashi ◽  
Shuang Chang ◽  
Peng Jin
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Genetic Basis ◽  
Fragile X ◽  
Biological Pathways ◽  
Fragile X Mental Retardation ◽  
Mental Retardation Protein ◽  
Mirna Pathway ◽  
Microrna Pathway

Deficits in cognitive functions lead to mental retardation (MR). Understanding the genetic basis of inherited MR has provided insights into the pathogenesis of MR. Fragile X syndrome is one of the most common forms of inherited MR, caused by the loss of functional Fragile X Mental Retardation Protein (FMRP).MicroRNAs (miRNAs) are endogenous, single-stranded RNAs between 18 and 25 nucleotides in length, which have been implicated in diversified biological pathways. Recent studies have linked the miRNA pathway to fragile X syndrome. Here we review the role of the miRNA pathway in fragile X syndrome and discuss its implication in MR in general.

scholarly journals Fragile X syndrome: clinical and cytogenetic studies

1998 ◽  
Vol 56 (1) ◽  
pp. 09-17 ◽  
Author(s):  
TÊMIS MARIA FÉLIX ◽  
JOÃO MONTEIRO DE PINA-NETO
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Clinical Evaluation ◽  
Fragile X ◽  
Clinical Signs ◽  
Behavioral Characteristics ◽  
Narrow Face ◽  
High Arched Palate ◽  
Cytogenetic Studies ◽  
Individuals With Mental Retardation

Three families with the fragile X syndrome were studied with the aim to establish the most frequent clinical signs in the affected individuals and heterozygous women. The clinical evaluation, IQ level measurements and cytogenetic studies were performed in 40 subjects, 20 males and 20 females. The fragile X diagnosis was confirmed in all the male individuals with mental retardation. In the postpubertal subjects the most frequent clinical signs were inner canthal distance < 3.5 cm, macro-orchidism, long and narrow face and high arched palate while in the prepubertal subjects the behavioral characteristics as hyperactivity and poor eye contact were the most frequent and were observed in all patients. Twenty six percent of the heterozygous women presented with mental retardation and showed clinical signs rather than behavioral ones. All male individuals with mental retardation were observed as having fragile X [fra(X)] in lymphocytes culture. Sixty three percent of women showed fra(X). There was a positive correlation between the frequency of fra(X) and the clinical characteristics. We emphasize the importance of the clinical evaluation in the study of familial mental retardation and in the screening of isolated cases with suspect of having the fragile X syndrome.

scholarly journals Macroorchidism in FMR1 Knockout Mice Is Caused by Increased Sertoli Cell Proliferation during Testicular Development*

Endocrinology ◽  
1998 ◽  
Vol 139 (1) ◽  
pp. 156-162 ◽  
Author(s):  
Karin E. Slegtenhorst-Eegdeman ◽  
Dirk G. de Rooij ◽  
Miriam Verhoef-Post ◽  
Henk J. G. van de Kant ◽  
Cathy E. Bakker ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Proliferation ◽  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Sertoli Cell ◽  
Knockout Mice ◽  
Messenger Rna ◽  
Fragile X ◽  
Fsh Receptor ◽  
Cgg Repeat

Abstract The fragile X syndrome is the most frequent hereditary form of mental retardation. This X-linked disorder is, in most cases, caused by an unstable and expanding trinucleotide CGG repeat located in the 5′-untranslated region of the gene involved, the fragile X mental retardation 1 (FMR1) gene. Expansion of the CGG repeat to a length of more than 200 trinucleotides results in silencing of the FMR1 gene promoter and, thus, in an inactive gene. The clinical features of male fragile X patients include mental retardation, autistiform behavior, and characteristic facial features. In addition, macroorchidism is observed. To study the role of Sertoli cell proliferation and FSH signal transduction in the occurrence of macroorchidism in fragile X males, we made use of an animal model for the fragile X syndrome, an Fmr1 knockout mouse. The results indicate that in male Fmr1 knockout mice, the rate of Sertoli cell proliferation is increased from embryonic day 12 to 15 days postnatally. The onset and length of the period of Sertoli cell proliferation were not changed compared with those in the control males. Serum levels of FSH, FSH receptor messenger RNA expression, and short term effects of FSH on Sertoli cell function, as measured by down-regulation of FSH receptor messenger RNA, were not changed. We conclude that macroorchidism in Fmr1 knockout male mice is caused by an increased rate of Sertoli cell proliferation. This increase does not appear to be the result of a major change in FSH signal transduction in Fmr1 knockout mice.

scholarly journals Alterations of Amino Acids and Monoamine Metabolism in Male Fmr1 Knockout Mice: A Putative Animal Model of the Human Fragile X Mental Retardation Syndrome

2001 ◽  
Vol 8 (4) ◽  
pp. 285-298 ◽  
Author(s):  
Michael Gruss ◽  
Katharina Braun
Keyword(s):  
Amino Acids ◽  
Animal Model ◽  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Knockout Mice ◽  
Fragile X ◽  
Fragile X Mental Retardation ◽  
Behavioral Abnormalities ◽  
Cortical Regions ◽  
Knockout Animals

The Fragile X syndrome, a common form of mental retardation in humans, is caused by silencing the fragile X mental retardation (FMR1) geneleading to the absence of the encoded fragile X mental retardation protein 1 (FMRP). We describe morphological and behavioral abnormalities for both affected humans and Fmr1 knockout mice, a putative animal model for the human Fragile X syndrome. The aim of the present study was to identify possible neurochemical abnormalities in Fmr1 knockout mice, with particular focus on neurotransmission. Significant region-specific differences: of basal neurotransmitter and metabolite levels were found between wildtype and Fmr1 knockout animals, predominantly in juveniles (post-natal days 28 to 31). Adults (postnatal days 209 to 221) showed only few abnormalities as compared with the wildtype. In juvenile knockout mice, aspartate and taurine were especially increased in cortical regions, striatum, hippocampus, cerebellum, and brainstem. In addition, juveniles showed an altered balance between excitatory and inhibitory amino acids in the caudal cortex, hippocampus, and brainstem. We detected very few differences in monoamine turnover in both age stages. The results presented here provide the first evidence that lack of FMRP expression in FMRP knockout mice is accompanied by age-dependent, region-specific alterations in neurotransmission.

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