Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Duchenne muscular dystrophy is a muscle-wasting disease accompanied by a variable, but often significant degree of mental retardation, possibly due to the absence of dystrophin. However, the function of brain type dystrophin remains insufficiently clear. With this background, in order to study the cell-specific regulation of brain type dystrophin expression in mice, we generated transgenic mice carrying the 2.1 kb 5'-fragment of the mouse brain type dystrophin gene, fused to the coding region of the bacterial lacZ gene. Three transgenic mice lines showed lacZ expression in the cerebral cortex. However, lacZ expression was not detected in the CA region of the hippocampus. These results suggest that the 2.1 kb 5'-fragment of the mouse brain type dystrophin gene contains the regulatory element required for its expression in the cerebral cortex, but not in the hippocampus.
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PMID:2.1 kb 5'-flanking region of the brain type dystrophin gene directs the expression of lacZ in the cerebral cortex, but not in the hippocampus. 909 55

Experimental evidence and pathological observation indicate that human cytomegalovirus (HCMV) has a tropism for cells of the nervous system, including both neuronal and glial cells. As demonstrated in animal models, after a viremic phase, the virus may reach the brain, where it may cause mild infection or severe encephalitis. The nervous system is one of the principal target organs in congenital HCMV infections and in HCMV-infected AIDS patients. In the former case, mortality is high and neurological sequelae, such as mental retardation, are frequent; in the latter it may lead to a progressively wasting encephalopathy and death within a few weeks. The diagnosis of the nervous system manifestations due to HCMV can now rely upon the detection of HCMV DNA in cerebrospinal fluid by means of polymerase chain reaction. However, the current antiviral treatments of these complications are of limited effect.
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PMID:Cytomegalovirus infections of the nervous system. 945 Feb 26

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant form of muscular dystrophy characterized by progressive weakness and wasting of the facial, shoulder-girdle and upper arm muscles. The gene locus for FSHD is mapped to the subtelomeric region of chromosome 4q35, in which smaller EcoRI fragments (10 to 33 kb) are detected in most families by Southern blot analysis. The purpose of this study is to clarify the frequency and clinical/genetical features of early-onset FSHD in Japanese patients with 4q35-FSHD. In a series of 231 patients from 145 families with 4q35-FSHD, there were 31 patients (13.4%; male: female = 12:19) of 29 families (20%) with early-onset FSHD, 16 of whom were sporadic. Genetic analysis revealed that they had significantly smaller sized EcoRI fragments (range, 10 to 23 kb; mean 14.1 kb) than the other patients (range, 12 to 33 kb; mean 19.6 kb) (p < 0.001, U-test). All patients with the smallest EcoRI fragments (10 to 11 kb) were sporadic cases with early onset. Mental retardation (10/11) and epilepsy (4/11) was often observed in them, but not in the other patients. In early-onset FSHD, tongue muscle involvement (8/31) and swallowing disturbance (2/31), which has been regarded as exclusion criteria of FSHD, were also present. The onset of gait disturbance was significantly earlier (mean age = 11.9) in early-onset FSHD compared to the other group (mean age = 28.7). All patients with early-onset FSHD showed gait disturbance before 28 years of age. In conclusion, Japanese early-onset FSHD patients tend to have large gene deletions on chromosome 4q35, and show severe and variable phenotypes.
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PMID:[Clinical and genetical features of Japanese early-onset facioscapulohumeral muscular dystrophy]. 1213 83

This article provides a discussion of deficiencies in the data collection on disabilities in Pakistan, identifies data sources, and makes recommendations for improving the quality of the data. Major trends in disabilities are identified. In Pakistan, there is social stigma attached to persons with disabilities. Disabilities are concealed within families so as not to limit the marriage prospects of relatives who might otherwise be suspected of carrying defective genes. Religion perpetuates superstitions about the disabled. Families bear an extra expense in caring for a disabled member, due to loss of additional labor, increased demands on resources for taking care of the disabled member, and increased need to compensate with higher fertility. There is a lack of social institutional support for care of the disabled. The population censuses of 1961 and 1981 were the first to collect information on the disabled. The inadequacy of census data led to the initiation of a national survey in 1984/85 for collecting data on blindness, deafness, mutism, leprosy, retardation, lameness, and handicaps. A special in-depth survey on disabilities was also conducted in Islamabad and Rawalpindi districts in 1986. This survey focused on mental retardation, visual and hearing disabilities, deformity and wasting of the limbs, and physical disabilities, such as paralysis. This survey was the most valid but it was not comparable to prior surveys. Trends indicate a smaller number of disabled at older ages. Specific disabilities by age showed some peculiar age patterns that suggest unreliability. Data from the 1984/85 survey show higher sex ratios for all disabilities for certain provinces compared to the national ratios. If the trend accurately reflects increased disabilities, the education of high risk groups must be improved, accessibility to medical care must be increased, and the population needs to be educated about the disabled. Government social programs need more accurate assessments of the causes of disability and the extent and duration of disablement.
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PMID:The population of persons with disabilities in Pakistan. 1231 84

Danon disease, an X-linked cardioskeletal myopathy caused by primary deficiency of lysosome-associated membrane protein-2 (LAMP-2), is clinically characterized by cardiomyopathy, myopathy, and variable mental retardation. The pathological hallmark of the disease is the absence of LAMP-2 immunohistochemical staining in muscle. The LAMP-2 gene mutations reported thus far are generally private mutations. We describe two cases of Danon disease with different clinical presentation, in whom we identified the same exon skipping mutation c.928G>A in the LAMP-2 gene. The first patient was affected by an early onset myopathy and hypertrophic cardiomyopathy (HCM) that partially improved with drug treatment. A first muscle biopsy at age 4 months showed markedly increased glycogen, and acid maltase deficiency was ruled out biochemically. A second muscle biopsy, performed at age 3(1/2) years, showed very mild abnormalities. The second child at age 15 years had mild, diffuse muscle weakness and wasting, moderate mental deficiency, and HCM. Two serial biopsies performed at age 8 and 15 years showed similar findings of multiple esterase-positive vacuoles in type I myofibers. In both patients the immunohistochemical study demonstrated the absence of LAMP-2 in skeletal muscle.
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PMID:Phenotypic heterogeneity in two unrelated Danon patients associated with the same LAMP-2 gene mutation. 1621 5

Hereditary spastic paraplegias (HSP) are neurodegenerative diseases mainly characterized by lower limb spasticity associated, in complicated forms, with additional neurological signs. We have analysed a large series of index patients (n = 76) with this condition, either from families with an autosomal recessive inheritance (n = 43) or isolated patients (n = 33), for mutations in the recently identified SPG11 gene. We found 22 truncating mutations, including the first four splice-site mutations, segregating in seven isolated cases and 13 families. Nineteen mutations were novel. Two recurrent mutations were found in Portuguese and North-African patients indicating founder effects in these populations. The mutation frequency varied according to the phenotype, from 41%, in HSP patients presenting with a thin corpus callosum (TCC) visualized by MRI, to 4.5%, in patients with mental impairment without a TCC. Disease onset occurred during the first to the third decade mainly by problems with gait and/or mental retardation. After a mean disease duration of 14.9 +/- 6.6 years, the phenotype of 38 SPG11 patients was severe with 53% of patients wheelchair bound or bedridden. In addition to mental retardation, 80% of the patients showed cognitive decline with executive dysfunction. Interestingly, the phenotype also frequently included lower motor neuron degeneration (81%) with wasting (53%). Slight ocular cerebellar signs were also noted in patients with long disease durations. In addition to a TCC (95%), brain MRI revealed white matter alterations (69%) and cortical atrophy (81%), which worsened with disease duration. In conclusion, our study reveals the high frequency of SPG11 mutations in patients with HSP, a TCC and cognitive impairment, including in isolated patients, and extends the associated phenotype.
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PMID:Mutations in SPG11 are frequent in autosomal recessive spastic paraplegia with thin corpus callosum, cognitive decline and lower motor neuron degeneration. 1807 67

The heteromeric inwardly rectifying Kir4.1/Kir5.1 K(+) channel underlies the basolateral K(+) conductance in the distal nephron and is extremely sensitive to inhibition by intracellular pH. The functional importance of Kir4.1/Kir5.1 in renal ion transport has recently been highlighted by mutations in the human Kir4.1 gene (KCNJ10) that result in seizures, sensorineural deafness, ataxia, mental retardation, and electrolyte imbalance (SeSAME)/epilepsy, ataxia, sensorineural deafness, and renal tubulopathy (EAST) syndrome, a complex disorder that includes salt wasting and hypokalemic alkalosis. Here, we investigated the role of the Kir5.1 subunit in mice with a targeted disruption of the Kir5.1 gene (Kcnj16). The Kir5.1(-/-) mice displayed hypokalemic, hyperchloremic metabolic acidosis with hypercalciuria. The short-term responses to hydrochlorothiazide, an inhibitor of ion transport in the distal convoluted tubule (DCT), were also exaggerated, indicating excessive renal Na(+) absorption in this segment. Furthermore, chronic treatment with hydrochlorothiazide normalized urinary excretion of Na(+) and Ca(2+), and abolished acidosis in Kir5.1(-/-) mice. Finally, in contrast to WT mice, electrophysiological recording of K(+) channels in the DCT basolateral membrane of Kir5.1(-/-) mice revealed that, even though Kir5.1 is absent, there is an increased K(+) conductance caused by the decreased pH sensitivity of the remaining homomeric Kir4.1 channels. In conclusion, disruption of Kcnj16 induces a severe renal phenotype that, apart from hypokalemia, is the opposite of the phenotype seen in SeSAME/EAST syndrome. These results highlight the important role that Kir5.1 plays as a pH-sensitive regulator of salt transport in the DCT, and the implication of these results for the correct genetic diagnosis of renal tubulopathies is discussed.
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PMID:Renal phenotype in mice lacking the Kir5.1 (Kcnj16) K+ channel subunit contrasts with that observed in SeSAME/EAST syndrome. 2163 11

Myotonic dystrophy type 1 (DM-1) is a multi-system disorder affecting the muscles, brain, cardiovascular system, endocrine system, eyes and skin. Diagnosis is made by clinical, electrodiagnostic and genetic studies. This study aimed to determine the correlation between CTG expansion and distribution of muscle weakness and clinical and electrophysiological findings. Genetically confirmed DM-1 patients presenting to Shariati Hospital between 2005 and 2011 were included in this study. Clinical, electrodiagnostic and genetic testing was performed and the correlation between CTG expansion and distribution of muscle weakness and clinical and electromyographic findings was studied. Thirty-three genetically confirmed DM-1 patients were enrolled. Myotonia, bifacial weakness and distal upper limb weakness were seen in all patients. Diabetes mellitus was found in one patient (3%), cardiac disturbance in eight (24.2%), cataracts in eight (24.2%), hypogonadism in five (15.2%), frontal baldness in 13 (39.4%), temporalis wasting in 14 (42.4%), temporomandibular joint disorder in seven (21.2%) and mental retardation in eight (24.2%). The mean number of CTG repeats, measured by Southern blot, was 8780 (range 500-15,833). A negative correlation was found between CTG expansion and age of onset. Temporalis wasting and mental retardation were positively correlated with CTG expansion. No relationship was found between weakness distribution, electromyographic findings, other systemic features and CTG expansion. In this study of DM-1 in Iran, we found a correlation between CTG expansion and age of onset, temporalis wasting and mental disability. No correlation between CTG expansion and electrodiagnostic and other clinical findings were detected.
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PMID:Correlation between distribution of muscle weakness, electrophysiological findings and CTG expansion in myotonic dystrophy. 2441 93

Myotonic dystrophy (MyD) is a neuromuscular disease that is autosomal dominant and the most common form of muscular dystrophy affecting adults. The clinical features of MyD include a multisystemic disorder characterized by myotonia, progressive muscle weakness and wasting, cataracts, premature balding and mental retardation. The most severe type of MyD is classified as congenital MyD (CMyD). The muscle weakness in CMyD is very severe, but muscle development can be observed in the period of growth. However, no clinical case of this type has been reported yet. Therefore, we report on a girl with CMyD who had an increase in muscle strength over a four-year period. The girl with CMyD participated in this study from the age of 9 to the age of 12. The measurement of muscle strength was recorded as the maximum score of grip strength with the use of dynamometers. Grip strength was assessed once a year by the same two physical therapists. Grip strength of CMyD for each year was markedly weak when compared with the normal controls, but muscle strength changed within some specific growth areas. The muscle weakness in CMyD was remarkable, but the result showed that specific muscle strength of CMyD in childhood was actually increased.
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PMID:The Change of Grip Strength in a Patient with Congenital Myotonic Dystrophy Over a 4-year Period. 2579 86

Spinal muscular atrophy (SMA) is a hereditary neuromuscular disorder, which causes progressive muscle weakness and in severe cases respiratory failure and death. Although the majority of the SMA cases are autosomal recessive, there is an autosomal dominant variant of SMA that primarily affects the lower extremities, known as 'spinal muscular atrophy - lower extremity, dominant' (SMALED). Mutations in the Dynein Cytoplasmic 1 Heavy Chain 1 (DYNC1H1) gene were the first to be associated with SMALED. Here we report a family with SMALED caused by a pathogenic heterozygous missense c.1809 A>T, p.glu603Asp mutation in DYNC1H1. The main clinical features were congenital hip displacement, talipes, delayed motor development, wasting and weakness in lower limbs with relative sparing of upper extremities and very slow disease progression. SMALED is extremely rare and only a handful of families have been reported. Over the years other phenotypes including Charcot Marie Tooth type 2 and hereditary mental retardation with cortical neural migration defects have also been reported to be caused by DYNC1H1 mutations. This report aims to increase our awareness of SMALED and various other phenotypes associated with mutations in this gene.
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PMID:A missense mutation in DYNC1H1 gene causing spinal muscular atrophy - Lower extremity, dominant. 2930


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