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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study describes the cytogenetic findings in cases suspected with chromosomal abnormalities, in cases of mental retardation, multiple congenital malformations, clinical features of Down's syndrome, Klinefelter's syndrome, Turner's syndrome, ambiguous sex, sterility, amenorrhea and history of repeated spontaneous abortions in couples. Cytogenetic studies were done in 144 of the total 205 cases. In all, 57 (39.58%) were shown to have chromosomal abnormality and of these, 34 cases (25.7%) were Down's syndrome. Sex chromosome abnormality was found in 19 cases (13.2%). The results confirm the significant contribution of chromosomal abnormalities in the genesis of mental retardation, and abnormal sexual development.
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PMID:Cytogenetic studies in a population suspected to have chromosomal abnormalities. 224 22

We performed a cytogenetic study on 140 nonpolymalformed patients with mental retardation of clinically undefined origin, using a high resolution banding technique, to determine how much chromosome abnormalities contribute to the etiology of this condition. A total of 15 patients (10.7%) were found to have autosomal or sex chromosomal abnormalities. Autosomal abnormalities included partial monosomy (5 cases), reciprocal translocation (one case), 13/14 robertsonian translocation (3 cases), unbalanced translocation (one case), inverted duplication of 15q (one case) and mosaic trisomy 21 (one case). Sex chromosomal abnormalities comprised structural rearrangement of the short arm of the X chromosome (one case) and 47, XXY in a pure or mosaic form (two cases). It should be noted that four out of the 5 cases of partial monosomy had subtle interstitial deletions, which might have been unidentified by the conventional G-banding method alone. In one case of the robertsonian translocation 46,XY,t(13;14)/45,XY,t(13;14), a small deletion was thought to have occurred in the cells with a chromosome number of 45. Comparison of clinical features of the 15 chromosomally abnormal patients with those of patients with normal karyotypes did not show any clinical parameter indicative of chromosome imbalance. These results suggest that a subtle chromosomal deletion is specific to mental retardation associated with few malformations. We believe that diagnostic evaluation of mentally retarded patients, even if nonmalformed, should include chromosome analysis using a high resolution banding technique.
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PMID:A cytogenetic study of nonpolymalformed patients with mental retardation of clinically undefined etiology: application of a high resolution banding technique. 272 4

A cytogenetic survey of 470 mentally retarded children from three different sources is reported. Thirty-eight patients (8.08%) were found to have recognizable chromosome abnormalities, including 4 cases of sex chromosomes and 34 cases of autosomes. The most prominent category of abnormality was trisomic 21, a total of 26 cases of this type was found in this study. Sex chromosome abnormalities contribute very little to the etiology of mental retardation. From the results of our three groups of patients as well as from those surveyed by others, it is concluded that the more severe the degree of mental retardation, the higher the incidence of chromosome abnormalities.
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PMID:A cytogenetic survey of mentally retarded children in Taiwan: final report on the incidence of chromosome abnormalities. 653 21

Schizophrenia is a common and serious psychiatric illness with strong evidence for genetic causation, but no specific loci yet identified. Chromosomal abnormalities associated with schizophrenia may help to understand the genetic complexity of the illness. This paper reviews the evidence for associations between chromosomal abnormalities and schizophrenia and related disorders. The results indicate that 22q11.2 microdeletions detected by fluorescence in-situ hybridization (FISH) are significantly associated with schizophrenia. Sex chromosome abnormalities seem to be increased in schizophrenia but insufficient data are available to indicate whether schizophrenia or related disorders are increased in patients with sex chromosome aneuploidies. Other reports of chromosomal abnormalities associated with schizophrenia have the potential to be important adjuncts to linkage studies in gene localization. Advances in molecular cytogenetic techniques (i.e., FISH) have produced significant increases in rates of identified abnormalities in schizophrenia, particularly in patients with very early age at onset, learning difficulties or mental retardation, or dysmorphic features. The results emphasize the importance of considering behavioral phenotypes, including adult onset psychiatric illnesses, in genetic syndromes and the need for clinicians to actively consider identifying chromosomal abnormalities and genetic syndromes in selected psychiatric patients.
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PMID:Chromosomal abnormalities and schizophrenia. 1081 3

49,XXXXY and 48,XXXY syndromes are rare gonosomal aneuploidies in which the affected individuals present with characteristic facial and skeletal malformations, intrauterine growth retardation, and psychomotor retardation. Psychological, endocrinologic and orthopedic disorders constitute the major problems in the clinical follow-up. Sex chromosome abnormalities should especially be kept in mind in the evaluation of patients with micropenis, mental retardation and accompanying behavioral disturbances. Management mandates a multidisciplinary approach with pediatric endocrinology, pediatric surgery, orthopedics, psychiatry, and clinical genetic evaluations.
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PMID:Rare sex chromosome aneuploidies: 49,XXXXY and 48,XXXY syndromes. 1981 77

49,XXXXY and 45,X syndromes are sex chromosome aneuploidies in which the affected individuals present with hypergonadotropic hypogonadism, short or long stature, and skeletal malformations. Psychological, endocrinological, and orthopaedic disorders constitute the major problems in the clinical follow-up. We report a family with two rare entities: 49,XXXXY and 45, X. Sex chromosome abnormalities should especially be in mind in the evaluation of patients with micropenis, mental retardation, and hypergonadotropic hypogonadism. Management mandates a multidisciplinary approach with pediatric endocrinology, pediatric surgery, orthopaedics, psychiatry, and clinical genetic evaluations. To our knowledge, our cases are the first to report the sibling patients with 49,XXXXY and 45,X.
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PMID:First Report of Two Rare Entities in a Family: 49,XXXXY and 45,X. 2879 10