Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917816 (mental retardation)
 15,867 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is currently thought that fragile X syndrome (FraX; the most common inherited form of learning disability) results from having more than 200 cytosine-guanine-guanine (CGG) trinucleotide repeats, with consequent methylation of the fragile X mental retardation (FMR1) gene and loss of FMR1 protein (FMRP). It was also considered that premutation carriers (with 55-200 CGG repeats) are unaffected, although a tremor/ataxia syndrome has recently been described in older adult male carriers. We reported that premutation expansion of CGG trinucleotide repeats affects brain anatomy, which, together with other studies, indicates that the molecular model for FraX needs modification. However, there are few studies on the cognitive ability of adult male premutation carriers. Thus, we selected 20 male premutation carriers on the basis of their genetic phenotype, and compared them to 20 male controls matched on age, IQ and handedness. We investigated intellectual functioning, executive function, memory, attention, visual and spatial perception, and language and pragmatics. The premutation carriers had significant impairments on tests of executive function (Verbal Fluency, Trail Making Test and Tower of London) and memory (Names sub-test of the Doors and People, Verbal Paired Associates Immediate Recall and Visual Paired Associates Delayed Recall sub-tests of the WMS-R, and Category Fluency Test for natural kinds). We therefore suggest that CGG trinucleotide repeats in the premutation range affect specific neuronal circuits that are concordant with specific neuropsychological deficits; and that these deficits reflect an emerging neuropsychological phenotype of premutation FraX.
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PMID:A neuropsychological investigation of male premutation carriers of fragile X syndrome. 1538 Oct 24

A portable monitoring device was developed to assist in the management of children with a learning disability. The device was designed for continuous home monitoring of blood oxygen saturation, heart and respiration rates, and patient activity. It could be worn on a belt, while the patient continued normal activities. Data were stored on a multimedia card and automatically transmitted to a PC at prescribed intervals via a Bluetooth wireless link. From the PC the data were transmitted to a Web server, where the information was made available to the staff involved in the patient's care. Preliminary clinical studies were performed with nine patients (four with Down's syndrome, three with cerebral palsy and two with mental retardation). Patients and families considered the device easy to use and to wear. The monitoring device identified events of possible clinical interest. Although it was designed for monitoring children with a learning disability, it may also be useful with other groups, such as elderly people.
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PMID:A multi-functional, portable device with wireless transmission for home monitoring of children with a learning disability. 1549 89

This study analyzed the occurrence of learning disability (LD) in adults with childhood-onset epilepsy and the impact of LD on medical and social outcome. Any LD occurred in 76%: in 57% of mentally normal (IQ>85), in 67% of mentally near-normal (IQ=71-85), and, self-evidently, in all mentally retarded (IQ<71) adults. Half of the patients (51%) with LD had mental retardation. In multivariate analysis, mental retardation and subsequent LD were predicted by occurrence of cerebral palsy (odds ratio [OR]=3.83; 95% confidence interval [CI]=1.77-8.28, P=0.0006), onset of epilepsy before the age of 6 years (OR=3.63, 95% CI=1.57-8.42, P=0.0026), and poor early effect of drug therapy (OR=2.78, 95% CI=1.43-5.39, P=0.0025). Among mentally normal or near-normal subjects, a symptomatic etiology of epilepsy was the only predictor (OR=7.72, 95% CI=3.02-19.76). The degree of LD significantly affected medical, social, and educational long-term outcomes.
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PMID:Learning disability: occurrence and long-term consequences in childhood-onset epilepsy. 1558 42

This paper gives the results of a needs assessment of a group of learning-disabled forensic patients from two Strategic Health Authority areas in the north of England. The patients were found to be a heterogeneous group with wide-ranging psychiatric needs. The majority were cared for outside their geographical area of origin, either in specialist NHS facilities or the independent sector. Those with an additional diagnosis of mental illness were most likely to be detained in NHS facilities within the region: a diagnosis of personality disorder was associated with placement in either a high secure setting or the independent sector. Individuals with a clinical diagnosis of mental retardation were most likely to be detained in services provided by specialist learning disability/mental health trusts out of area. There was a small group of females who were all placed outside the region. Offending behaviour was most likely to consist of violence against the person, sexual offences and arson. The majority assessed were felt to have long term needs. The study raised important implications for future provision of forensic services in the area, particularly the need to offer services with treatment programmes tailored to the needs of the population under review.
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PMID:Needs assessment in forensic learning disability. 1589 41

Prader-Willi Syndrome (PWS) is a genetic disorder characterized by hypotonia, mental retardation or learning disability, hyperphagia and compulsive eating due to hypothalamic dysfunction. Obesity is a major cause of increased morbidity and mortality among patients with PWS. Gastric restrictive surgery has been associated with partial breakdown of the staple-line in PWS. We report two patients with PWS associated with morbid obesity and obstructive sleep apnea who underwent biliopancreatic diversion (BPD). A 27-year-old male with BMI 52 kg/m(2) and a 20 year-old female with BMI 64 kg/m(2) underwent BPD. No perioperative complications were observed. After BPD, the male's BMI was 36.7 kg/m(2) at 12 months and the female's BMI was 48.4 kg/m(2) at 28 months, with excess weight loss 58% and 48%, respectively. They developed loose stools associated with eating. These patients have shown a considerable improvement in hypersomnia and respiratory difficulties. BPD proved to be an effective approach to weight loss in PWS, resulting in improvement of sleep apnea, behavior problems and quality of life.
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PMID:Results of biliopancreatic diversion in two patients with Prader-Willi syndrome. 1597 69

Children with language problems frequently experience social difficulty. This is the case not only for children diagnosed as having impairments such as autism spectrum disorder, Asperger syndrome (AS), or mental retardation but also for children falling into diagnostic categories traditionally considered to be primarily language based (e.g., language impairment, learning disability). In considering what interventions might be most effective, it is important to consider how various aspects of development are connected. This article describes causal networks in which various factors influence the relationship between language deficits and social difficulties. Case descriptions of Joseph, an adolescent with language impairment, and Cari, a 6-year-old diagnosed with AS, illustrate the complexity of this relationship and demonstrate how intervention might be designed to facilitate positive social communication outcomes.
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PMID:Social competence in children with language impairment: making connections. 1615 53

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

Loss-of-function mutations or abnormal expression of the X-linked gene encoding methyl CpG binding protein 2 (MeCP2) cause a spectrum of postnatal neurodevelopmental disorders including Rett syndrome (RTT), nonsyndromic mental retardation, learning disability, and autism. Mice expressing a truncated allele of Mecp2 (Mecp2(308)) reproduce the motor and social behavior abnormalities of RTT; however, it is not known whether learning deficits are present in these animals. We investigated learning and memory, neuronal morphology, and synaptic function in Mecp2(308) mice. Hippocampus-dependent spatial memory, contextual fear memory, and social memory were significantly impaired in Mecp2(308) mutant males (Mecp2(308/Y)). The morphology of dendritic arborizations, the biochemical composition of synaptosomes and postsynaptic densities, and brain-derived neurotrophic factor expression were not altered in these mice. However, reduced postsynaptic density cross-sectional length was identified in asymmetric synapses of area CA1 of the hippocampus. In the hippocampus of symptomatic Mecp2(308/Y) mice, Schaffer-collateral synapses exhibited enhanced basal synaptic transmission and decreased paired-pulse facilitation, suggesting that neurotransmitter release was enhanced. Schaffer-collateral long-term potentiation (LTP) was impaired. LTP was also reduced in the motor and sensory regions of the neocortex. Finally, very early symptomatic Mecp2(308/Y) mice had increased basal synaptic transmission and deficits in the induction of long-term depression. These data demonstrate a requirement for MeCP2 in learning and memory and suggest that functional and ultrastructural synaptic dysfunction is an early event in the pathogenesis of RTT.
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PMID:Learning and memory and synaptic plasticity are impaired in a mouse model of Rett syndrome. 1639 2

Congenital hypothyroidism (CH) is the commonest treatable cause of mental retardation. The prevelance is 1/3000 - 1/4000 live births worldwide. The importance of CH is that, the longer the diagnosis of CH is delayed, the higher the risk of mental retardation and neurologic sequale; such as poor motor coordination, ataxia, spastic diplegia, muscular hypotonia, strabismus, learning disability and diminished attention span. The most common cause of permenant CH is thyroid dysgenesis (85-90%) in which the transcription factors TTF1,TTF2 and PAX8 would appear to be obvious candidate genes in the aetiology. Especially cardiac defects and some other birth defects are described in patients with CH. Inborn errors of thyroid hormonogenesis are responsible for 10-15% of CH cases and usually have autosomal recessive inheritance, consistent with a single gene mutation. Transient CH is very common in prematures with an estimate of 10% of CH babies identified on newborn screening, or 1 in 40,000 neonates. CH neonates are usually symptom-free and the most encountered symptoms are prolonged jaundice, large fontanelles and umbilical hernia. In general, the extent of clinical findings depends on the cause, severity and duration of hypothyroidism. An elevated TSH>20 microm Iu/L and a decreased concentration of T4 confirms the diagnosis of CH. Infants with permanant abnormalities of thyroid function mostly have a serum TSH concentration > 50 microm Iu/L. Ultrasonography, thyroid scintigraphy, bone x ray of the knee and serum thyroglobulin concentration are the other essentials after diagnosis to clarify the status of the thyroid and the severity of hypothyroidism. The higher doses of 10- 15 microm g/kg/day and the commencement of treatment before 2 weeks gave rise to better long term outcome of CH patients. In the follow up of the patients noncompliance is the most important problem and serum freeT4 or T4 and TSH should be obtained at each visit to adjust the doses of L-thyroxine. Still a small number of patients with severe hypothyroidism in utero or reflected by clinical signs and symptoms extremely low T4 levels and delayed bone age may have intellectual deficits despite normal intelligence.
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PMID:Congenital hypothyroidism clinical aspects and late consequences. 1644 57

We report on a case of a 6-year-old female with partial trisomy 8p(21-23) associated with autism, mild dysmorphic features, and moderate learning disability. Although mental retardation is a common finding in patients with mosaic trisomy 8 or partial trisomy of various regions of chromosome 8, only two cases associated with autism have been reported so far. Also, in our case clinical manifestations were mild compared to other patients with duplication of the same region of chromosome 8. Although there has been no strong evidence for linkage on chromosome 8 in any of the genome-wide linkage studies so far, the possibility that this segment includes genes involved in the etiology of autism should be further explored.
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PMID:A case of partial trisomy of chromosome 8p associated with autism. 1660 35


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