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

The prevalence, in children aged under 15, of severe impairments of social interaction, language abnormalities, and repetitive stereotyped behaviors was investigated in an area of London. A "socially impaired" group (more than half of whom were severely retarded) and a comparison group of "sociable severely mentally retarded" children were identified. Mutism or echolalia, and repetitive stereotyped behaviors were found in almost all the socially impaired children, but to a less marked extent in a minority of the sociable severely retarded. Certain organic conditions were found more often in the socially impaired group. A subgroup with a history of Kanner's early childhood autism could be identified reliably but shared many abnormalities with other socially impaired children. The relationships between mental retardation, typical autism, and other conditions involving social impairment were discussed, and a system of classification based on quality of social interaction was considered.
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PMID:Severe impairments of social interaction and associated abnormalities in children: epidemiology and classification. 15 84

A clinical and cytogenetic investigation carried out in a special institution for mentally retarded patients revealed 82 cases of oligophrenia, amongst whom were found 56 normal karyotypes (68.3%). Out of 25 karyotypes with chromosome anomalies or variants there were 18 cases of trisomy 21 and 7 others: one case of mosaicism with balanced translocation, 46,XX/46,XX,6p+,17q-; one case of partial trisomy, 46,XX,11q+; one case of pericentric inversion, 46,XY,inv(1) (p13,q21); one case with 8% chromosome breaks; three cases of marker chromosomes, of which one was of karyotype 46,XX,1qh+, and two (oligophrenic sisters) 46,XX,21p+. Moreover, there was an interesting case of testicular feminisation in a 9-year-old girl with karyotype 46,XY. The authors' results corroborate those obtained in several important previous studies based on much larger numbers of patients. Amongst the 56 cases where the karyotype was shown to be normal, there were 15 for whom a probably exogenic cause of the oligophrenia could be established, occurring mainly during the perinatal period. The authors were also able to confirm that the genetic factor plays an important role in the incidence of mental retardation, since in 22 examined patients, i.e. 26.8% of all cases, the condition was of familial type. Some interesting observations of idiopathic oligophrenia are reported, as well as several cases with well-known syndromes (Crouzon's and Cornelia de Lange's syndromes, hypothyroidism). Two cases of incest between father and daughter, which had produced children with serious oligophrenia associated, in one case, with deaf-mutism, microphthalmia, microcephaly and sclerocornea, are also discussed. The data show that mental retardation can frequently have a genetic cause, either of mendelian, chromosomal or multifactorial origin.
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PMID:[A clinical and cytogenetic investigation carried out in a special institution for mentally retarded patients: preliminary results concerning 82 cases of oligophrenia (author's transl)]. 102 53

The occurrence of deaf-mutism and goiter unassocaited with creatinism or mental retardation in euthyroid patients is known as Pendred's Syndrome. It is considered due to a single mutant recessive gene responsible for both the goiter and deafness. The penetrance is high, the intenseness of expressivity may vary within the same family and only one generation is affected. The extremely atypical hyperplasia seen in such goiters has been considered malignant. In 1956 the author reported a family in which 4 of 6 sibilings demonstrated Pendred's Syndrome. Three of the 4 had undergone thyroidectomy, two were considered to have carcinoma. Nineteen years later the family is again reported. The fourth sibling has recently undergone thyroidectomy. This thyroid demonstrated the same atypical hyperplasia as seen in the elder two siblings. The 19 year followup of this family has shown no evidence of recurrence or metastases, indicating that the atypical hyperplasia is probably not malignant. Pendred's Syndrome is described and certain suggestions are made for the counseling of the parents and the treatment and counseling of those children so afflicted.
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PMID:Goiter and deaf mutism. 121 96

A new type of non-specific X linked mental retardation is described in a three generation family. The three affected males had severe mental retardation (IQ 20 to 30), mutism, growth failure, frequent infections, seizures, and the following minor anomalies: brachycephaly, frontal hair whorl, square face, large mouth, thick lips, and prognathism. There was not a characteristic facies. Normal laboratory studies on the proband included a karyotype with fragile X screening, skeletal survey, blood amino acid, urine organic acid, and HGPRT levels. Linkage analysis was performed with 10 X chromosome DNA probes of which probe DXS255 at chromosomal region Xp11.22 gave a maximal two point lod score of 2.10 if phase was inferred and 1.20 if it was not. Crossovers were shown with probes mapping to regions Xp22, Xp21, and Xq28. Comparison of these patients with 80 X linked causes of mental retardation, including 41 which might be classified as 'non-specific', showed no other disorders compatible with the phenotypic and linkage data.
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PMID:Non-specific X linked mental retardation with aphasia exhibiting genetic linkage to chromosomal region Xp11. 847 12

The occurrence of congenital deafness, mutism and goitre unassociated with cretinism or mental retardation in euthyroid patients is known as Pendred's Syndrome. It has been estimated that 4-10 % of children with congenital deafness suffer from this condition. The perceptive hearing loss is considered to be present at birth although it is frequently not recognized for several years. The cause of the hearing defect is a congenital bilateral malformation of the cochlea of the Mondini type. The goitre is not recognized clinically at birth or in early childhood. It becomes apparent in the pre-pubertal years when it presents as a colloid enlargement progressing to a nodular goitre. The thyroid defect has been shown to be a partial defect in iodine organification leading to the underproduction of thyroxine and subsequent thyroid hyperplasia. The syndrome is caused by a single mutant recessive gene responsible for both the deafness and goitre. Its autosomal mechanism gives an equal incidence in both sexes, unusual in thyroid disease. This article reviews the current aspects of pathogenesis and treatment of this syndrome and reports its occurrence in two Sudanese siblings.
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PMID:Goitre and deaf-mutism. 181 81

Between 1986 and 1988 a door-to-door survey was conducted on a stable rural population of 60,820 in central Ethiopia. Trained lay health workers made a complete census and identified cases with symptoms and signs of neurological disorders, using specially designed questionnaires which, in a previous pilot study, were found to have a sensitivity of 91% and specificity of 85%. Neurological disorders in the rural population were epilepsy, postpoliomyelitis paralysis, mental retardation, peripheral neuropathy (mainly due to leprosy), and deaf-mutism with prevalence rates (cases/100,000 population) of 520, 240, 170, 150 and 130, respectively. The prevalence rates of the other less common neurological disorders were 62 for hemiparesis (15 of which were for cerebrovascular accidents), 20 for cerebral palsy, 16 for optic atrophy, 12 for perceptive deafness, 10 for tropical spastic paraparesis, 7 for Parkinson's disease and 5 for motor neuron disease, ataxia and chorea/athetosis. Among related non-neurological conditions, blindness, locomotor disability and deafness were predominant. The significance and role of such a neuroepidemiological study in laying the strategies for the prevention of neurological disorders and rehabilitation of patients are discussed in the context of a developing country.
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PMID:Community-based study of neurological disorders in rural central Ethiopia. 208 51

Disorders caused by iodine deficiency continue to be a major health problem in many underdeveloped areas of the world. The most significant is the impaired mental and physical development which occurs as a result of iodine deprivation early in life. Individuals in affected communities show a spectrum of abnormalities which can be attributed to two interacting pathological processes. Fetal hypothyroidism in the first and early second trimester predominantly affects the developing nervous system causing deaf-mutism and mental retardation. If hypothyroidism occurs in the early postnatal period the main abnormalities are growth stunting and related somatic abnormalities. Subclinical deficits of intellectual and motor development may also be found in apparently normal individuals living in affected areas. Although dietary iodine deficiency is clearly the major aetiological factor in both endemic goitre and cretinism, cofactors such as goitrogens, other trace element deficiencies and immunological mechanisms may greatly modify the expression of these disorders. Iodine supplementation programmes form the basis of the public health strategy in combatting these disorders. Where the iodization of foodstuffs is not feasible, an alternative is the use of iodine containing oil which can be given orally or intramuscularly to provide a long-lasting supply of iodine.
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PMID:Endemic goitre and iodine deficiency disorders--aetiology, epidemiology and treatment. 306 26

We describe a familial reciprocal translocation between the distal part of the short arm of chromosome 2 and the long arm of chromosome 10. Five individuals in two generations had multiple congenital anomalies. Their karyotypes were 46,XX or XY, -10, + der(10), t(2;10)(p24;q26). Seven persons were balanced translocation carriers whose karyotypes were 46,XX or XY,t(2;10)(p24;q26). Common manifestations included mental retardation, strabismus, narrow high-arched palate, wide alveolar ridges, other facial abnormalities, genital abnormalities and mutism. The phenotype of the unbalanced individuals is compared to that of previously published cases of the syndrome of partial duplication 2p and to reported patients with partial deletion of 10q.
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PMID:Familial reciprocal translocation, t(2;10)(p24;q26), resulting in duplication 2p and delection 10q. 709 94

The proportions of subjects with severe social impairment and those retaining the features of childhood autism were investigated in a population of mentally retarded adults in a long-stay hospital. The results confirmed the findings of an earlier study of mentally retarded children (Wing & Gould, 1979) that the administrative category of mental retardation includes a substantial minority of people with severe impairment of two-way social interaction. Such social impairment occurred in 38% of the adult population and was very significantly associated with abnormalities of communication and imaginative activities. Muteness, repetitive stereotyped behaviour, including repetitive speech, and a range of behaviour problems also occurred more frequently in the socially impaired group. Two methods of sub-classifying the socially impaired were compared. Classification based on the severity of social impairment gave more statistically significant associations with behavioural and psychological variables than did a method based on the presence or absence of typical autism. The implications of these findings and their relevance for management and planning of services for the mentally retarded were briefly discussed.
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PMID:Prevalence of autism and related conditions in adults in a mental handicap hospital. 714 7

This work reports the presence of endemic cretinism in a small district located inside an endemic goiter area in north-eastern Sicily, personally described. The study covers 19 mental defectives (11 females and 8 males, mean age 35.8 +/- 15.5 yr) selected on the basis of severe mental retardation recognized by the local doctors. No systematic survey for cretinism was carried out in the total population. Marked mental retardation was evident in all subjects. Nine of them exhibited clinical and biochemical signs of hypothyroidism (myxedematous cretins). The 10 others were clinically euthyroid and had deaf-mutism and/or pyramidal tract dysfunction (neurological cretinism). Familial aggregation of cretinism was also observed. In both myxedematous and neurological cretins and urinary iodine excretion was very low, but not significantly different from that recorded in the euthyroid controls of the same area. The data available do not clarify the pathogenesis of endemic cretinism in Sicily. However, the marked height retardation, the observation of delayed bone maturation and the severity of mental deficiency suggest that thyroid failure was present in early life. The presence of endemic cretinism today in Sicily constitutes a strong argument in favour of the immediate introduction of adequate iodine prophylaxis.
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PMID:Endemic cretinism in Sicily. 732 Apr 34


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