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)

An analysis of the linkage of a non-syndromal form of X-linked mental retardation (MRX1) with a number of markers on the X chromosome was performed in a large pedigree. The affected males had moderate mental retardation; in all other clinical respects and cytogenetically they were normal. No recombinants were observed between the MRX1 gene and the marker DXS14 (p58.1) located at Xp11-cen (Z (max.) = 2.12 at theta = 0.00). Recombination was observed between the MRX1 gene and the markers DXS7 and DXYS1 which flank DXS14. This form of XLMR maps to the centromeric portion of the X-chromosome.
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PMID:A non-syndromal form of X-linked mental retardation (XLMR) is linked to DXS14. 317 66

We report on a family with 4 affected males in 3 generations with a previously unreported X-linked mental retardation/multiple congenital anomaly (XLMR/MCA) syndrome. The propositus was a 7-year-old Latin American moderately retarded male with: prenatal and postnatal overgrowth; short, broad upturned nose; large mouth; midline groove of tongue, lower alveolar ridge and lower lip; submucous cleft palate; supernumerary nipples; 13 ribs; Meckel's diverticulum; intestinal malrotation; coccygeal skin tag and bony appendage; hypoplastic index fingernails; postaxial polydactyly of the right hand, bilateral syndactyly of 2nd and 3rd fingers; and tibial clinodactyly of 2nd toes. His sister's son, a premature infant who died at 4 months, had nearly identical manifestations. The propositus and his nephew had normal chromosomes. A brother and son of the sister of the mother of the propositus were similarly affected and both died in the newborn period. The mother of the propositus had a large mouth, coccygeal skin tag and bony appendage, and hypoplastic index fingernails. This distinct mental retardation/multiple congenital anomaly syndrome is added to the growing list of presently known X-linked MCA/MR syndromes.
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PMID:A new X-linked mental retardation-overgrowth syndrome. 653 55

Golabi and Rosen (1984) have reported on a new X-linked mental retardation/multiple congenital anomalies (XLMR/MCA) syndrome of pre- and postnatal overgrowth, characteristic "coarse" facial appearance with macrostomia, midline groove of tongue, lower alveolar ridge and lip, submucous cleft of palate, supernumerary nipples, intestinal anomalies, supernumerary pair of ribs, anomalies of sacrum and tailbone, hypoplastic index fingernails, postaxial polydactyly and other digital anomalies. This was an incompletely recessive trait with some manifestations evident in an obligatory carrier. Here we report on a second family (studied at the University of Wisconsin for over 9 years) in which 3 males born to half-sisters and their mother were affected with the Golabi-Rosen syndrome (GRS). Overgrowth was not a prominent manifestation in these affected males. Presence of cystic kidneys, peculiar skin changes and hepatomegaly make it likely that the Golabi-Rosen syndrome is an X-linked MCA/dysplasia/MR syndrome. Its metabolic basis remains unknown. It seems to be an incompletely recessive trait.
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PMID:The Golabi-Rosen syndrome--report of a second family. 653 56

The fact that a connective tissue dysplasia is a component of the Martin-Bell syndrome was a fortuitous discovery. A 26-month-old developmentally delayed boy had many signs of a connective tissue dysplasia for which he was referred to a University center where he was found to be fragile (X)-positive without confirmation of a connective tissue problem. Sensitized by these events and observations, we were able to predict at a glance in an unrelated family the fragile (X)-positive status of 2 subsequently referred brothers with mental retardation and prominent manifestations of connective tissue dysplasia. Thus, the Martin-Bell syndrome is an incompletely recessive, pleiotropic trait involving CNS, testes and connective tissues. The characteristic facial appearance of affected males largely represents interaction of mental retardation, congenital CNS based muscle hypotonia and connective tissue dysplasia. At the 1983 NIH workshop on XLMR there was a general consensus that a connective tissue dysplasia is a component of the Martin-Bell syndrome, a fact since confirmed by others on the basis of objective measurements of finger joint hypermobility and frequent presence of mitral valve prolapse.
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PMID:Discovery of a connective tissue dysplasia in the Martin-Bell syndrome. 671 89

The gene responsible for nonsyndromic mental retardation in a family with 7 affected males has been localized to Xp21. The maximal two-point lod score was 3.31 for tight linkage to marker DXS1202 in Xp21.3-p22.3 with crossovers between the 3' portion of the DMD gene (DXS1234) proximally and locus DXS989 distally. The XLMR gene in this family has been assigned the designation MRX29. The localization overlaps with at least six other MRX entities linked to the distal short arm of the X chromosome.
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PMID:Nonsyndromic X-linked mental retardation: review and mapping of MRX29 to Xp21. 900 95

In this report we describe two unrelated young males with severe mental retardation, persisting hypotonia, and constipation. A maternal uncle of one of these two boys died at the age of 18 months and presented the same clinical symptoms. The triad mental retardation, hypotonia, constipation is a characteristic finding in the FG syndrome, an X-linked mental retardation syndrome. At the present time, there is increasing evidence that the FG syndrome-phenotype may be present in different XLMR conditions, e.g. the fragile X syndrome. In addition to the triad severe mental retardation, hypotonia, constipation, the present two male index patients had a characteristic facial appearance with nasal hypoplasia, relative microcephaly and pre- and postnatal overgrowth. The question is raised whether the present two males are examples of a specific entity within the FG-syndrome-like phenotype.
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PMID:Distinct facial appearance with nasal hypoplasia, constipation, severe mental retardation and hypotonia in two unrelated young males. 900 1

Nance-Horan syndrome (NHS) is a rare X-linked condition comprising congenital cataract with microcornea, distinctive dental, and evocative facial anomalies. Intellectual handicap was mentioned in seven published NHS patients. We performed a clinical study focused on psychomotor development, intellectual abilities, and behavior in 13 affected males in four NHS families, and present the results of a neuropsychological evaluation in 7 of them. Our study confirms that mental retardation (MR) can be a major component of the NHS. Combining our data with those from the literature leads to a frequency of MR in NHS of around 30%. In most cases, MR is mild or moderate (80%) and not associated with motor delay. Conversely, a profound mental handicap associated with autistic traits may be observed. MR has intra- and inter-familial variability but does not appear to be expressed in carriers. Awareness of MR in NHS may be of importance in the management of the patients, especially in terms of education. Cloning and characterization of the gene and analysis of mutations will be an important step towards understanding the molecular basis of mental deficiency in NHS, and in delineation from the other XLMR conditions at Xp22.
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PMID:Mental retardation in Nance-Horan syndrome: clinical and neuropsychological assessment in four families. 926 1

We describe a large family with nonspecific X-linked mental retardation (MRX 47). An X-linked recessive transmission is suggested by the inheritance from the mothers in two generations of a moderate to severe form of mental retardation in six males, without any specific clinical findings. Two point linkage analysis demonstrated significant linkage between the disorder and two markers in Xq23 (Zmax = 3.75, theta = 0). Multipoint linkage analyses confirmed the significant linkage with a maximum lod score (Z = 3.96, theta = 0) at DXS1059. Recombination events observed with the flanking markers DXS1105 and DXS8067 delineate a 17 cM interval. This interval overlaps with several loci of XLMR disorders previously localized in Xq23-q24, which are reviewed herein.
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PMID:Gene for nonspecific X-linked mental retardation (MRX 47) is located in Xq22.3-q24. 933 63

This is the sixth edition of the catalogue of XLMR genes, ie X-linked genes whose malfunctioning causes mental retardation. The cloning era is not yet concluded, actually much remains to be done to account for the 202 XLMR conditions listed in this update. Many of these may eventually prove to be due to mutations in the same gene but the present number of 33 cloned genes falls surely short of the actual total count. It is now clear that even small families or individual patients with cytogenetic rearrangements can be instrumental in pinning down the remaining genes. DNA chip technology will hopefully allow (re)screening large numbers of patients for mutations in candidate genes or testing the expression levels of many candidate genes in informative families. Slowly, our knowledge of the structure and functioning of the proteins encoded by these genes is beginning to cast some light on the biological pathways required for the normal development of intelligence. Correlations between the molecular defects and the phenotypic manifestations are also being established. In order to facilitate the exchange of existing information and to allow its timely update, we prepared the first edition of the XLMR database (available at http://homepages.go.com/~xlmr/home.htm) and invite all colleagues, expert in the field, to contribute with their experience.
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PMID:XLMR genes: update 2000. 1131 39

In an institutionalised population of 471 mentally retarded adult residents (436 males and 35 females), 22 males (i.e. 5 % of the male population) had XLMR, accounting for 36.1 % of the residents diagnosed with a monogenic disorder (n = 61). Fragile X syndrome (FRAXA) was diagnosed in 16 residents, X-linked mental retardation with marfanoid habitus (Lujan-Fryns syndrome) in 2, and non-specific X-linked mental retardation (MRX) in 4 males. The 4 MRX-patients included 3 male sibs of a family, carrying a mutation in the IL-1 receptor accessory protein-like gene, and one male patient member of the MRX-44 family (linkage with LOD-score of 2.90). In the group of 215 males with idiopathic mental retardation (MR), family histories and pedigree data were compatible with XLMR in 35 males (35/215 = 16.3 %) from 32 families. Of these 35 males, 5.7 % were microcephalic with dysmorphic features and 5.7 % macrocephalic; micro-orchidism and macro-orchidism were each found in 11.4 %. One macrocephalic male had also macro-orchidism and dysmorphic features. In this study, the diagnosis of XLMR could thus be proposed in 57 males i.e. 13.1 % of the total male population. The clinical phenotype, behavioural problems and follow-up data in these different subgroups of XLMR are presented.
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PMID:The clinical phenotype in institutionalised adult males with X-linked mental retardation (XLMR). 1133 18


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