scholarly journals Common Clinical Characteristics and Rare Medical Problems of Fragile X Syndrome in Thai Patients and Review of the Literature

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Chariyawan Charalsawadi ◽  
Juthamas Wirojanan ◽  
Somchit Jaruratanasirikul ◽  
Nichara Ruangdaraganon ◽  
Alan Geater ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Attention Deficit ◽  
Clinical Characteristics ◽  
Fragile X ◽  
Clinical Findings ◽  
Medical Problems ◽  
Prepubertal Boys ◽  
Iq Scores ◽  
Physical Features ◽  
Index Cases

Background. Clinical characteristics of fragile X syndrome (FXS) have been well documented in Caucasians, whereas in Asians they have rarely been described. Those that have been conducted used small cohorts that utilized DNA for diagnosis and larger cohorts that utilized cytogenetics for diagnosis. This study is to describe clinical characteristics of FXS in a large cohort of Thai patients diagnosed by standard molecular methods. Methods. Seventy-seven index cases and 46 affected relatives diagnosed with FXS were recruited into the study. To determine frequencies of common characteristics of FXS in prepubertal boys, we reviewed 56 unrelated cases aged between 18 and 146 months. To list rare medical problems, we reviewed 75 cases aged between 8 months to 71 years old, including 53 index cases and 22 affected relatives. In addition, we selected 16 clinical studies from various ethnicities for comparison with our findings. Results. In prepubertal boys with FXS, attention deficit and/or hyperactivity, prominent ears, macroorchidism, and elongated face were observed in 96%, 80%, 53%, and 48% of patients, respectively, whereas recognizable X-linked inheritance presented in 11% of patients. IQ scores ranged between 30 and 64 (mean ± SD = 43±9, n=25). We observed clinical findings that rarely or have never been reported, for example, medulloblastoma and tetralogy of Fallot. Conclusion. Attention deficit and/or hyperactivity and prominent ear are the most common behavioral and physical features in prepubertal boys with FXS, respectively. There are differences in frequencies of clinical characteristics observed between ethnicities; however, it is difficult to draw a solid conclusion due to different recruitment criteria and sample sizes within each study.

Fragile-X Syndrome Ascertained by the Presence of Macro-orchidism in a 5-Month-Old Infant

PEDIATRICS ◽  
1984 ◽  
Vol 74 (5) ◽  
pp. 883-886
Author(s):  
Rivka Carmi ◽  
David L. Meryash ◽  
John Wood ◽  
Park S. Gerald
Keyword(s):  
Mental Retardation ◽  
Family History ◽  
Physical Examination ◽  
Fragile X Syndrome ◽  
Fragile X ◽  
Actual Measurement ◽  
The Family ◽  
Careful Measurement ◽  
Prepubertal Boys ◽  
Testicular Size

The fragile-X syndrome, an X-linked form of mental retardation, is estimated to affect one in every 1,000 to 2,000 live-born male infants. Most commonly, fragile-X syndrome has been detected only after patients clearly demonstrate developmental delay, and frequently detection occurs only if the family history is consistent with X-linked mental retardation. Macro-orchidism is a finding commonly associated with the fragile-X syndrome. It has been suggested that the sparsity of reports of macro-orchidism among prepubertal boys with the fragile-X syndrome might be due to lack of careful measurement of the testes rather than to initiation of the enlargement at puberty. A 5-month-old infant with fragile-X syndrome, ascertained through testicular enlargement noted by actual measurement of testicular size as part of his physical examination, is reported.

Health Supervision for Children With Fragile X Syndrome

PEDIATRICS ◽  
1996 ◽  
Vol 98 (2) ◽  
pp. 297-300
Author(s):  
Keyword(s):  
Mental Retardation ◽  
Developmental Delay ◽  
Fragile X Syndrome ◽  
X Chromosome ◽  
Dna Analysis ◽  
Fragile Site ◽  
Fragile X ◽  
Physical Features ◽  
Relationship Of ◽  
The Relationship

This set of guidelines is designed to assist pediatricians in caring for children with fragile X syndrome confirmed by DNA analysis (Table). Occasionally pediatricians are called on to advise a pregnant woman who has been informed of a prenatal diagnosis of fragile X syndrome. Therefore, guidelines are also offered for this situation. Fragile X syndrome is usually diagnosed during childhood and is characterized by developmental delay or mental retardation, characteristic physical features, and abnormal behavioral patterns.1,2 The distinctive fragile site on the X chromosome was first described in 1969 as a discontinuous site on the long arm of the X chromosome present after cell culture under folate-deficient conditions. In 1977 the relationship of this site to X-linked mental retardation was noted, and fragile X syndrome began to be defined. Since that time, the cytogenetic, molecular, and clinical features of the condition have been more clearly defined,3 and it is now recognized as the most common hereditary cause of mental retardation. Its frequency has been estimated to be approximately per 2500 to 1 per 1250 males and 1 per 5000 to 1 per 1600 females. The phenotype of fragile X syndrome in males often has a number of distinctive, recognizable features, including developmental delay or mental retardation, a prominent forehead, a long, thin face and a prominent jaw that appear late in childhood or early adolescence, large protuberant and slightly dysmorphic ears, and the presence of or ultimate development of macro-orchidism. This phenotype can be very subtle, is not always apparent, and becomes more identifiable with age.2

scholarly journals Fragile X syndrome and fragile X-associated disorders

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2112 ◽  
Author(s):  
Akash Rajaratnam ◽  
Jasdeep Shergill ◽  
Maria Salcedo-Arellano ◽  
Wilmar Saldarriaga ◽  
Xianlai Duan ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Fragile X ◽  
Protein Product ◽  
Social Deficits ◽  
Synaptic Connections ◽  
Ovarian Insufficiency ◽  
The Past ◽  
Ataxia Syndrome ◽  
Physical Features ◽  
Psychiatric Problems

Fragile X syndrome (FXS) is caused by a full mutation on the FMR1 gene and a subsequent lack of FMRP, the protein product of FMR1. FMRP plays a key role in regulating the translation of many proteins involved in maintaining neuronal synaptic connections; its deficiency may result in a range of intellectual disabilities, social deficits, psychiatric problems, and dysmorphic physical features. A range of clinical involvement is also associated with the FMR1 premutation, including fragile X-associated tremor ataxia syndrome, fragile X-associated primary ovarian insufficiency, psychiatric problems, hypertension, migraines, and autoimmune problems. Over the past few years, there have been a number of advances in our knowledge of FXS and fragile X-associated disorders, and each of these advances offers significant clinical implications. Among these developments are a better understanding of the clinical impact of the phenomenon known as mosaicism, the revelation that various types of mutations can cause FXS, and improvements in treatment for FXS.

Pituitary-Gonadal axis in prepubertal boys with the fragile X syndrome

1991 ◽  
Vol 39 (3) ◽  
pp. 374-375 ◽  
Author(s):  
P. S. J. Moore ◽  
A. E. Chudley ◽  
J. S. D. Winter
Keyword(s):  
Fragile X Syndrome ◽  
Fragile X ◽  
Prepubertal Boys

scholarly journals An “Omic” Overview of Fragile X Syndrome

Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 433
Author(s):  
Olivier Dionne ◽  
François Corbin
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Fragile X ◽  
Neurodevelopmental Disorder ◽  
Medical Problems ◽  
Biochemical Alterations ◽  
Fragile X Mental Retardation ◽  
Wide Range

Fragile X syndrome (FXS) is a neurodevelopmental disorder associated with a wide range of cognitive, behavioral and medical problems. It arises from the silencing of the fragile X mental retardation 1 (FMR1) gene and, consequently, in the absence of its encoded protein, FMRP (fragile X mental retardation protein). FMRP is a ubiquitously expressed and multifunctional RNA-binding protein, primarily considered as a translational regulator. Pre-clinical studies of the past two decades have therefore focused on this function to relate FMRP’s absence to the molecular mechanisms underlying FXS physiopathology. Based on these data, successful pharmacological strategies were developed to rescue fragile X phenotype in animal models. Unfortunately, these results did not translate into humans as clinical trials using same therapeutic approaches did not reach the expected outcomes. These failures highlight the need to put into perspective the different functions of FMRP in order to get a more comprehensive understanding of FXS pathophysiology. This work presents a review of FMRP’s involvement on noteworthy molecular mechanisms that may ultimately contribute to various biochemical alterations composing the fragile X phenotype.

scholarly journals Clinical Characteristics of Fragile X Syndrome Patients in Japan

2020 ◽  
Author(s):  
Tetsuya Okazaki ◽  
Kaori Adachi ◽  
Kaori Matsuura ◽  
Yoshitaka Oyama ◽  
Madoka Nose ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Clinical Characteristics ◽  
Fragile X

Fragile X Syndrome in Humans and Mice

1996 ◽  
Vol 45 (1-2) ◽  
pp. 93-108 ◽  
Author(s):  
B. A. Oostra
Keyword(s):  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Dendritic Spines ◽  
Pyramidal Neurons ◽  
Fragile Site ◽  
Fragile X ◽  
Methylation Status ◽  
Physical Symptoms ◽  
Post Mortem Brain ◽  
Iq Scores

Fragile X syndrome is the most common cause of interited mental retardation in humans, with a frequency of approximately 1 in 1200 males and 1 in 2500 females [1]. It is second only to Down syndrome as a genetic cause of mental retardation, which has an overall frequency of 1 in 600. These frequency estimates suggest that fragile X syndrome accounts for approximately 3% of mental retardation in males, and perhaps as much as 20% in males with IQs between 30 and 55 [2]. The disease derives its name from the observation of a fragile site at Xq27.3 in cultured lymphocytes, fibroblasts and amniocytes [3].The phenotype of the fragile X syndrome is mental retardation, usually with an IQ in the 4-70 range [4] and a number of dysmorphic features: long face, everted ears and large testicles [for review see ref. 5] (Fig. 1). Not every patient shows all the physical symptoms, which are generally more apparent after childhood. Macroorchidism is a common feature of fragile X syndrome in more than 90% of postpuberal males. Some patients show hyperactivity and attention deficits as well as avoidance behaviour similar to autism. Affected females generally have a less severe clinical presentation, and their IQ scores are generally higher, with typically borderline IQs or mild mental retardation.No gross pathological abnormalities have been described in the brains of fragile X patients. Only a few post-mortem brain studies of fragile X males have been described and the information is very limited, presenting only non-specific findings such as brain atrophy, ventricular dilatation and pyramidal neurons with abnormal dendritic spines. It has been shown that the volume of the hippocampus was enlarged compared to controls [6], while a significantly decreased size of the posterior cerebellar vermis and increased size of the fourth ventricle was found [7]. Using magnetic resonance imaging it was shown that fragile X patients have an increased volume of the caudate nucleus [8]. The caudate volume is correlated with IQ and methylation status of the FMR1 gene.

Molecular studies in children with fragile X syndrome

2017 ◽  
Vol 5 (10) ◽  
pp. 4348
Author(s):  
Manjula Thulasi S.
Keyword(s):  
Differential Diagnosis ◽  
Intellectual Disability ◽  
Fragile X Syndrome ◽  
Chromosomal Aberrations ◽  
Fragile X ◽  
Single Gene ◽  
Blood Samples ◽  
Genetic Abnormalities ◽  
Molecular Studies ◽  
Iq Scores

Background: Fragile X Syndrome (FXS) is the most common single gene cause of Learning (intellectual) Disability (LD). FMR1 gene mutation is the commonest cause for this syndrome. The present study aims to analyze the incidence of the syndrome in Kerala population.Methods: Study was conducted among 86 children belonging to different places of Kerala. Children were selected on the basis of IQ scores and typical features of FXS. Blood samples were taken and routine karyotype was performed. PCR analyses were also conducted.Results: Majority of the children showed typical features of FXS. Out of 86 samples, six showed chromosomal aberrations were excluded. PCR analyses in 55 samples, screened 35 samples with FMR1 mutation, in which 26 samples having pre- mutation and 9 samples with full mutation.Conclusions: Through this genetic study, differential diagnosis of LD children with FXS, LD children with constitutional chromosome abnormalities, and LD children without any apparent genetic abnormalities could be established.

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