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)

X-linked hydrocephalus-stenosis of the aqueduct of Sylvius sequence (H-SAS, MIM number 30007) is a rare genetic disorder characterized by hydrocephalus, macrocephaly, adducted thumbs, spasticity, agenesis of corpus callosum and mental retardation. We confirm here the localisation of the mutant gene on Xq (Xq 2.8) by linkage analysis in a 5-generation pedigree (maximum lod score of Z = 4.57 at theta = 0.04 with probe St14 at locus DXS52) and emphasise the phenotypic variability of the disease. Ventricular dilatation in affected males was either severe and diagnosed antenatally or moderate and consistent with a long survival with little or no macrocephaly. Since other X-linked syndromes of mental retardation with spasticity and flexion deformities of the thumbs have previously been shown to map to the Xq 2.8 region as well (e.g. MASA syndrome and spastic paraplegia), the present results raise the question of whether H-SAS syndrome, MASA syndrome and spastic paraplegia with mental retardation might represent different phenotypic expression of various mutations at the same locus.
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PMID:X-linked hydrocephalus: clinical heterogeneity at a single gene locus. 139 13

Simpson-Golabi-Behmel Syndrome (SGBS), an X-linked encephalo-tropho-schisis syndrome described in fewer than a dozen families, is characterized by pre- and postnatal overgrowth, "coarse" face, minor facial anomalies and, in more severe cases, multiple congenital anomalies and mental retardation. We report on 2 brothers with overgrowth, macrocephaly, polydactyly, supernumerary nipples, and characteristic facial appearance. In addition, the propositus also had pulmonic stenosis and a cleft palate. The findings present in our patients are compared to those in the original patients and to those in patients described more recently. Despite the fact that our patients have most of the minor and several of the more severe malformations, they are not mentally retarded.
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PMID:Report of another family with Simpson-Golabi-Behmel syndrome and a review of the literature. 145 79

This report describes a new syndrome of dysgenesis of corpus callosum with other anomalies, presenting as microcephaly, mental retardation, spasticity, and unusual facial appearance in 2 Chinese brothers and their maternal cousins. To date, there has not been any case reported in the Chinese population of this syndrome. All 4 patients in this report present with the same unusual face. Hydrocephalus and/or interhemispheric cyst were found among them. This syndrome is transmitted as an X-linked trait. The nosology is reviewed and discussed.
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PMID:X-linked recessive inheritance of dysgenesis of corpus callosum in a Chinese family. 148 21

Linkage studies and cytogenetically visible deletions associated with nonspecific X-linked mental retardation (XLMR) and a specific form of deafness (DFN3) have indicated that the genes responsible for these disorders are located at Xq21. Using DNA probes from this region, we have studied several overlapping deletions spanning different parts of Xq21. This has enabled us to assign the DFN3 gene and a gene for nonspecific XLMR to an interval that encompasses the locus DXS232 and that is flanked by DXS26 and DXS121.
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PMID:Physical fine mapping of genes underlying X-linked deafness and non fra (X)-X-linked mental retardation at Xq21. 151 79

The Lowe oculocerebrorenal syndrome (OCRL; McKusick 309000) is an X-linked disorder characterized by congenital cataracts, muscular hypotonia, mental retardation, and Fanconi syndrome of the renal tubules. A pair of yeast artificial chromosomes (YACs) that span the Xq25-q26 translocation breakpoint in a female with OCRL were used as probes to screen cDNA libraries made from bovine lens and human kidney. The methods used to prepare the YACs as probes and to screen the libraries are presented in detail. Two different transcripts were found that map to the region around the Xq25-q26 breakpoint. These transcripts are now being studied to determine whether one or the other is a candidate gene for OCRL.
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PMID:Isolation of cDNA sequences around the chromosomal breakpoint in a female with Lowe syndrome by direct screening of cDNA libraries with yeast artificial chromosomes. 152 13

Lesch--Nyhan syndrome is an X-linked disease caused by the deficiency of hypoxanthine phosphoribosyltransferase, an enzyme involved in the purine salvage pathways. It is characterized by severe gout, choreoathetosis, self-mutilatory behaviour and mental retardation. The derivation of mice genetically deficient in this enzyme may help to elucidate the pathogenesis of the neurological abnormality where previously models using drug administration to mimic the disorder have had to suffice.
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PMID:Mouse models of hypoxanthine phosphoribosyltransferase deficiency. 152 24

The fragile-X syndrome accounts for up to 10% of individuals with mental handicap, and 50% of cases of X-linked mental retardation. Knowledge of the genetic basis of mental functioning, psychopathology, and neuropsychology is being furthered by this recently recognised condition. The disorder has considerable significance for psychiatrists, particularly, but by no means exclusively, those working in the field of mental handicap and with children. This review outlines the slow clarification of this complex and important behavioural phenotype and the implications of these advances for identification, diagnosis, genetic counselling and a wide range of management interventions.
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PMID:The fragile-X syndrome. On the way to a behavioural phenotype. 154 10

We describe three families with X-linked recessive Charcot-Marie-Tooth (CMT) neuropathies. The disease phenotype in family 1 was characterized by infantile onset, weakness of lower legs, areflexia, pes cavus, and mental retardation (2 of 5 patients). The disease phenotype in families 2 and 3 was characterized by late onset, distal weakness, and normal intelligence. Hereditary spastic paraparesis was also present in the CMT patients of family 2. Thirty X-linked DNA markers were used for linkage studies. A maximum lod score of +3.48 was obtained by multipoint linkage analysis for the DXS16 locus mapped at Xp22.2 in family 1. In families 2 and 3, there was suggestion of linkage of Xq26 markers; the peak multipoint lod score for these 2 CMT families was 1.81, at DXS144. These results were suggestive of heterogeneity. The joint analysis including both regions (Xp22.2 and Xq26) provided evidence against homogeneity (chi 2 = 9.12, P less than 0.005).
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PMID:X-linked recessive Charcot-Marie-Tooth neuropathy: clinical and genetic study. 155 86

Fragile X [fra (X)] syndrome is a frequently encountered form of mental retardation and is inherited as an X-linked semi-dominant trait with reduced penetrance. We report here the characterization of a highly polymorphic dinucleotide repeat, DXS 548, which is approximately 150 kb proximal to the fra(X) site and the associated FMR-1 gene. DXS 548 is tightly linked to the fra (X) syndrome locus (FRAXA) without recombination (LOD = 9.07 with q of 0) in selected families with crossovers between FRAXA and very closely linked flanking markers. This dinucleotide repeat could be useful in determining the parental origin of a new fra (X) mutations and evaluating the role of FMR-1 in X-linked non-specific mental retardation.
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PMID:Characterization of a highly polymorphic dinucleotide repeat 150 KB proximal to the fragile X site. 160 97

Gene localization was determined by linkage analysis in 5 families with non-specific X-linked mental retardation (MRX) and were MRX1, Xp11.4-q21.31; MRX10, Xp21.3-p11.4; MRX11, Xp21.3-p11.22; MRX12, Xp21.3-q21.1; and MRX13, Xp22.3-q21.22. Four of these localizations cross the dystrophin brain promoter, a candidate locus for MRX. None of the affected individuals who were tested showed variation suggestive of a deletion. No consistent clinical features were observed between or within 4 of the 5 families. In MRX12, prematurity or low birth weight, hypotelorism and short stature were seen in several affected males. Heterozygote manifestations occurred in 3 families. There was no evidence to suggest involvement of the same gene in more than one family, nor to clinically separate these families into distinct genetic entities. Non-overlapping localizations for MRX1 and MRX10 demonstrate the existence of at least 2 separate loci among these 5 families.
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PMID:Localization of non-specific X-linked mental retardation genes. 160 17


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