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Query: UMLS:C0004352 (autism)
 32,579 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Standardized cognitive, behavioral, and neuroanatomical data are presented on 2 unrelated boys with the FRAXE (FMR2) GCC expansion mutation. In the context of normal IQ, both boys had a history of developmental delay, including significant problems with communication, attention, and overactivity. Additionally, one child was diagnosed with autistic disorder. Data from these 2 cases are compared to analogous information from previous reports about individuals with the FRAXE or FRAXA (FMR1) mutation. These comparisons support the idea that FRAXE is associated with nonspecific developmental delay and possibly high-functioning autism.
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PMID:Cognitive, behavioral, and neuroanatomical assessment of two unrelated male children expressing FRAXE. 903 11

Unstable (CAG)n trinucleotide repeat microsatellites are hypothesized to cause schizophrenia. The (CAG)n microsatellite of dominant spinal cerebellar ataxia type 1 (SCA1) is a candidate schizophrenia gene. Autism results from expansions of (CGG)n and (GAA)n trinucleotide repeat stretches at fragile X syndrome (FRAXA), and the recessive Friedreich's ataxia (FA). Dominant ataxia genes may cause schizophrenia and recessive ataxia genes may cause autism. Syndromes with autism show purine synthesis defects (PSDs) and/or pigmentation defects (PDs). Autism is caused by very lengthy expansions of (CAG)n, (CGG)n and (GAA)n repeats, while schizophrenia results from much smaller (CAG)n and (CGG)n repeat expansions.
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PMID:Expanded (CAG)n, (CGG)n and (GAA)n trinucleotide repeat microsatellites, and mutant purine synthesis and pigmentation genes cause schizophrenia and autism. 979

The present paper addresses post mortem pathological and neuropathological findings in two males with fragile-X syndrome, aged 67 and 87 years. Both subjects died from sudden, unexpected cardiovascular causes, and both showed abnormalities of the mitral valve, ventricular hypertrophy and cardiomegaly. Both cases demonstrated macrocephaly characteristic of the classical Martin-Bell phenotype in FRAXA. There was increased brain weight in both cases: macroscopically, both cerebral and cerebellar hemispheres appeared normal, but dilated lateral ventricles were seen; and microscopic examination of the brain in case 2 showed normal hexalaminar architecture and no gross neuronal dropout. The hippocampus showed mild CA4 pyramidal cell loss and associated gliosis. The cerebellum showed focal Purkinje cell loss and corresponding Bergmann gliosis. Whilst there is a need to delineate the microscopic features of fragile-X syndrome from those of the ageing process, there is an urgent need for more systematic neuropathological studies of fragile-X syndrome; the increased brain weight and Purkinje cell loss in autism and fragile-X syndrome reopens the debate on these two conditions. The case for further research into the cardiac anomalies in fragile-X syndrome is also strengthened by the findings. Finally, the present report confirms the role of interstitial cell hyperplasia as the major cause of megalo-testes in this condition.
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PMID:Pathological and neuropathological findings in two males with fragile-X syndrome. 1071 53

Taxonomic features of fragile X syndrome (FXS) associated with the fragile X mutation have evolved over several decades. Males are more severely impacted cognitively than females, but both show declines in IQ scores as they age. Although many males with FXS exhibit autistic-like features, autism does not occur more frequently in males with FXS than among males with mental retardation (MR). FXS is caused by inactivation of the FMR1 gene located on Xq27.3. FMRP, the protein produced by FMR1, has been detected in most organs and in brain. In cells, it is located primarily in cytoplasm and contains motifs found in RNA-binding proteins. The FMRP N-terminal contains a functional nuclear localization signal which permits the protein to shuttle between cytoplasm and nucleus. FMR1 knockout mice show subtle behavioral and visual-spatial difficulties. Analysis of their brain tissue suggests absence of FMRP impairs synaptic maturation. Individuals with the fragile premutation produce FMRP, and the phenotype associated with the premutation has been controversial. However, there seems to be a higher incidence of premature ovarian failure in women with the premutation than is found in the general female population. This may be related to unusual increases in mRNA levels in premutation carriers.
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PMID:FMR1 gene and fragile X syndrome. 1118 Feb 23

In summary, autism genetics has moved from a time of identification of heritability and determination of risk of "lesser variants" or the "broader phenotype" in relatives to a phase where some cases of autism have a definite basis such as maternally inherited duplications of 15q11-q13, identification of mutations causing AS, Rett syndrome, and FRAXA. The first phase of genome-wide screens has not revealed definitive linkage, but as samples are enlarged and meta-analyses performed, the strongest linkage findings are likely to yield susceptibility variants once fine mapping proceeds. Recent statistical and molecular genetic analysis methods make the additional work feasible. However, frustrating it may be to be in this phase of the research, it is an essential part of the process of moving from identification of heritability in autism to understanding of the disorder in a way that may permit improved treatment in the future. If there is an advantage to autism being a complex rather than monogenic disorder, it is that the nature of multiplicative or interacting genetic risk is that prevention or treatment directed to any of the identified genetic risks may be sufficient to break a chain of pathophysiology. More genes increase the chance that one or more will have implications for treatment development sooner.
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PMID:Genetics of autism. 1135 2

Studies of the relationship between the fragile X (FRAXA) mutation and autism have been controversial. Although there are differences between the two populations, individuals with FRAXA and autism exhibit remarkably similar aberrant behavior patterns. We examined comparably aged children and adolescents with FRAXA or autism to determine whether longitudinal changes in cognitive ability and adaptive behavior were similar in the two groups. We found decreases in IQ scores in young children with FRAXA as well as in those with autism. Declines in IQ scores were steeper among children with FRAXA. Older children and adolescents with autism exhibit stable test-retest scores, whereas older children with FRAXA continue to show decreases. Comparable declines in adaptive behavior composite scores were observed in both groups, at all ages tested, and across all adaptive behavior domains.
J Autism Dev Disord 2002 Apr
PMID:Longitudinal changes in cognitive and adaptive behavior scores in children and adolescents with the fragile X mutation or autism. 1145 Aug 26

With the aim of analyzing which complementary tests are relevant in the diagnostic evaluation of individuals with pervasive developmental disorders, a protocol of clinical and laboratory evaluation was applied in 103 outpatients. The protocol included chromosomal analysis, screening for inborn errors of metabolism, cytogenetic and molecular study of the FRAXA, FRAXE, and FRAXF mutations, EEG, SPECT, and magnetic resonance imaging study. Eighty-four subjects concluded the complementary tests and were classified either as having autism, atypical autism or Asperger syndrome according to the DSM-IV criteria. Sixteen individuals, all bellonging to the two autistic groups, presented genetic or enviromental factors that may have lead to the behavioral disorders, showing the importance of diagnostic evaluation in this group of conditions. Neuroimaging and EEG findings were non-specific and occurred in similar proportion among the groups, being considered of relative low significance in the diagnostic evaluation of individuals with pervasive developmental disorders.
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PMID:Genetic and neurological evaluation in a sample of individuals with pervasive developmental disorders. 1280 92

Fragile X syndrome is a frequent genetic disease associated to developmental disorders, including learning disability, mental retardation, behavioral problems and pervasive developmental disorders (autism and related conditions). We studied a sample of 82 individuals (69 males and 13 females) presenting with pervasive developmental disorders using three techniques for the diagnosis of fragile X syndrome (FXS). Cytogenetic analysis detected the fragile site in four males, but only one showed a consistent positive rate. Molecular study based on the PCR technique was inconclusive for most females (92.3%), which where latter submitted to Southern blotting analysis, and for one male (1.4%), excluding the FRAXA mutation in the remaining male individuals (98.6%). Molecular tests using the Southern blotting technique confirmed only one positive case (1.2%) in a male subject. These results showed that Southern blotting analysis of the FRAXA mutation has the best sensitivity and specificity for the diagnosis of FXS but also validated the PCR technique as a confinable screening test.
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PMID:Laboratorial diagnosis of fragile-X syndrome: experience in a sample of individuals with pervasive developmental disorders. 1617 1

This study utilized retrospective video analysis to distinguish sensory-motor patterns in infants with fragile X syndrome (FXS) (n = 11) from other infants [i.e., autism (n = 11), other developmental delay (n = 10), typical (n = 11)] at 9-12 months of age. Measures of development, autistic features, and FMRP were assessed at the time of entry into the study. Home videos collected from families were edited and coded with previously validated procedures. Findings revealed a pattern of sensory-motor features (e.g., repetitive leg movements, posturing, less sophistication/repetitive use of objects) associated with FXS, and suggest these infants were most similar to the group of infants with other developmental delays, irrespective of co-existing autistic symptoms later in life. Infant sensory-motor features in the FXS group were more predictive of an early developmental milestone (i.e., age walking) than later, more broad, developmental outcomes, or FMRP. Implications for early identification and differential diagnosis are discussed.
J Autism Dev Disord 2005 10
PMID:Video analysis of sensory-motor features in infants with fragile X syndrome at 9-12 months of age. 1617 9

In a prospective study in Kuwait, 182 mentally retarded male patients who fulfilled 5 or more clinical criteria of fragile X syndrome were screened using polymerase chain reaction (PCR) testing. Twenty patients (11%) were highly suspected of having fragile X syndrome due to mutation at the FRAXA locus; none had mutation at the FRAXE locus. Of these, 11 (55%) were confirmed fragile-X-positive by both cytogenetic and PCR techniques. The most frequent clinical features were: prominent forehead, high arched palate, hyperextensible joints, long ears, prominent jaw, height > 10th centile and attention-deficit hyperactivity. Less common were avoidance of eye contact (45%), autism (45%) and seizures (30%). Large testes were found in 55% of cases. Pre-pubertal and post-pubertal clinical criteria were different.
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PMID:Fragile X syndrome: a clinico-genetic study of mentally retarded patients in Kuwait. 1620 16


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