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)

An X-linked pattern of transmission observed in four families with familial mental retardation in several generations was associated with a probable secondary constriction at the distal end of the q arms of the X chromosome. Twenty retarded males and no retarded females were observed. All available live retarded males and most of their normal mothers were found to have the abnormal X chromosome. The marker chromosome was shown to be the X chromosome in each case by Giemsa banding. In affected male and female carriers the marker chromosome varied in appearance and was not present in all metaphases. The significance of this study in relation to previously reported pedigrees showing non-specific X-linked mental retardation is discussed.
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PMID:Familial X-linked mental retardation with an X chromosome abnormality. 83

We describe a boy with the hypertelorism-hypospadias (BBB) syndrome. His mother and his maternal grandmother showed minor manifestations suggestive of the syndrome. The BBB syndrome is a syndrome of multiple congenital anomalies with mental retardation due a segregating mendelian mutation, either X-linked or autosomal. This paper reviews the literature on the subject and emphasizes the problem of identifying females at high risk of transmitting the condition.
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PMID:Studies of malformation syndromes of man VB: the hypertelorism-hypospadias (BBB) syndrome. Case report and review. 87 Mar 22

The observation of heritable fragile sites on human chromosomes prepared for lymphocyte cultures has been shown to depend on the type of tissue culture medium in which the lymphocytes are grown. The sites are observed at a much greater frequency when medium 199 is used than when RPMI 1640, Ham's F10, Eagle's (basal), and CMRL 1969 are used. One site on the X chromosome is of clinical significance in that it is a marker for X-linked mental retardation.
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PMID:Fragile sites on human chromosomes: demonstration of their dependence on the type of tissue culture medium. 87 51

In the course of investigation of 262 families with non-differentiated forms of oligophrenias it is established that in 48 families (18.3%) mental deficiency in sibs is caused by pathological mutations in the X-chromosome. Besides, it is not excluded that in certain inbred families oligophrenia in female persons is also, due to mutations linked with X-chromosome. This is supported by the dependence established between the frequency of the cases of oligophrenia among female persons and the inbreeding coefficient for the X-linked loci. The possibility of manifestation of the recessive genes of oligophrenia linked with X-chromosomes in heterozygous state is discussed.
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PMID:[Undifferentiated X-linked oligophrenias]. 91 33

The aim of the present work is to investigate the heredity of manic-depressive syndromes, in particular to test the hypothesis of a dominant X-linked transmission in these disorders. The Maximum Likelihood Estimate method was applied to linkage analysis between several X-linked genetic markers and bipolar manic-depressive illness, as well as to a control population of unipolar depressive patients. The genetic markers studied were deuteranopia and protanopia (two X-linked recessive markers) and the Xg blood group (X-linked dominant marker). The sampling methods were identical for both groups of patients and the family studies were performed "blind" (i,e. without knowledge of the proband's diagnosis). The results demonstrate the presence of strong linkage between manic-depressive (bipolar) illness, deuteranopia and protanopia. Linkage (although less strong) was also shown for bipolar illness and the Xg blood group. The genetic data are based on mathematical analysis of 36 informative kindreds ascertained from a sample of 134 manic-depressive patients. The results are concordant and demonstrate that, in this sample, manic-depressive (biopolar) psychosis is genetically transmitted through a X-linked dominant factor. We have also demonstrated the absence of linkage between unipolar depressive illness and the studied genetic markers in 16 informative kndreds ascertained from a sample of 71 unipolar patients. The genetic analyses described in this study demonstrate the existence of a manic-depressive syndrome which phenotype is dominant and determined by a gene located on the short arm of the Xchromosome. Apart from some forms of mental deficiency, manic-depressive psychosis represents the first known instance of a mendelian heredity machanism in psychiatric disorder;
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PMID:[Genetic study of mani-depressive psychoses]. 102 56

Eight patients in three families had mental retardation, characteristic facies and hands, and skeletal changes; the clinical features suggested to us that they had a syndrome previously thought to represent two entities described by Lowry and associates and by Coffin and associates, respectively. New findings include skeletal, orodental, and dermatoglyphic abnormalities and histopathologic changes suggesting that the syndrome is a heritable disorder of connective tissue. Severe expression in males and transmission through mildly affected females suggest X-linked or sex-influenced autosomal dominant inheritance.
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PMID:The Coffin-Lowry syndrome: an inherited faciodigital mental retardation syndrome. 113 53

Two families are described with an X-linked form of mental retardation in whom the affected males were found to have bilateral enlargement of the testes. No conclusive evidence of any endocrinological disturbance was found.
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PMID:X-linked mental retardation associated with macro-orchidism. 124 Sep 71

A seven-generation pedigree of apparent X-linked, nonspecific mental retardation is reported. There are 19 known affected males who appear to have received the gene through normal mothers. Retardation, lack of fine motor coordination, hyperactivity and a speech defect are the characteristics of affected individuals studied.
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PMID:X-linked nonspecific mental retardation. Report of a large kindred. 124 70

Norrie disease is a human X-linked recessive disorder of unknown etiology characterized by congenital blindness, sensory neural deafness and mental retardation. This disease gene was previously linked to the DXS7 (L1.28) locus and the MAO genes in band Xp11.3. We report here fine physical mapping of the obligate region containing the Norrie disease gene (NDP) defined by a recombination and by the smallest submicroscopic chromosomal deletion associated with Norrie disease identified to date. Analysis, using in addition two overlapping YAC clones from this region, allowed orientation of the MAOA and MAOB genes in a 5'-3'-3'-5' configuration. A recombination event between a (GT)n polymorphism in intron 2 of the MAOB gene and the NDP locus, in a family previously reported to have a recombination between DXS7 and NDP, delineates a flanking marker telomeric to this disease gene. An anonymous DNA probe, dc12, present in one of the YACs and in a patient with a submicroscopic deletion which includes MAOA and MAOB but not L1.28, serves as a flanking marker centromeric to the disease gene. An Alu-PCR fragment from the right arm of the MAO YAC (YMAO.AluR) is not deleted in this patient and also delineates the centromeric extent of the obligate disease region. The apparent order of these loci is telomere ... DXS7-MAOA-MAOB-NDP-dc12-YMAO.AluR ... centromere. Together these data define the obligate region containing the NDP gene to a chromosomal segment less than 150 kb.
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PMID:The Norrie disease gene maps to a 150 kb region on chromosome Xp11.3. 130 Nov 61

Fragile X syndrome is the most frequent form of inherited mental retardation and segregates as an X-linked dominant with reduced penetrance. Recently, we have identified the FMR-1 gene at the fragile X locus. Two molecular differences of the FMR-1 gene have been found in fragile X patients: a size increase of an FMR-1 exon containing a CGG repeat and abnormal methylation of a CpG island 250 bp proximal to this repeat. Penetrant fragile X males who exhibit these changes typically show repression of FMR-1 transcription and the presumptive absence of FMR-1 protein is believed to contribute to the fragile X phenotype. It is unclear, however, if either or both molecular differences in FMR-1 gene is responsible for transcriptional silencing. We report here the prenatal diagnosis of a male fetus with fragile X syndrome by utilizing these molecular differences and show that while the expanded CGG-repeat mutation is observed in both the chorionic villi and fetus, the methylation of the CpG island is limited to the fetal DNA (as assessed by BssHII digestion). We further demonstrate that FMR-1 gene expression is repressed in the fetal tissue, as is characteristic of penetrant males, while the undermethylated chorionic villi expressed FMR-1. Since the genetic background of the tissues studied is identical, including the fragile X chromosome, these data indicate that the abnormal methylation of the FMR-1 CpG-island is responsible for the absence of FMR-1 transcription and suggests that the methylation may be acquired early in embryogenesis.
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PMID:DNA methylation represses FMR-1 transcription in fragile X syndrome. 130 13


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