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

Nine cases are described of tetrasomy 18p resulting from the presence of an isochromosome 18p [i(18p)]. The initial diagnosis of i(18p) was by standard cytogenetic techniques and was confirmed by in situ hybridization with a biotinylated alphoid probe (L1.84) specific for the pericentric region of chromosome 18 and with a tritium-labeled chromosome 18 probe (B74) which hybridizes to the D18S3 locus situated at 18p11.3. The clinical features of the cases are summarized and shown to constitute a distinct and recognizable syndrome. Common features were low birth weight, a characteristic facies, neonatal hypotonia with subsequent limb spasticity, short stature, microcephaly, mental retardation, and seizure disorders. On the basis of size and cytogenetic banding a marker chromosome can be suspected to be an i(18p). In situ hybridization with the alphoid probe L1.84 provides confirmation of chromosome 18 origin. This more precise diagnosis will be an advantage in situations of pre- and postnatal diagnosis, since parents can be provided with a more confident prognosis for their child.
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PMID:The isochromosome 18p syndrome: confirmation of cytogenetic diagnosis in nine cases by in situ hybridization. 239 23

Diagnostic criteria for Rett syndrome (RS) were developed by representatives of the International Rett Syndrome Association and the Centers for Disease Control for use in future clinical and epidemiological studies. Necessary criteria are: normal prenatal and perinatal period; normal psychomotor development through the first 6 months of life; normal head circumference at birth, with subsequent deceleration of head growth; loss of purposeful hand skills; severely impaired expressive and receptive language; apparent severe mental retardation; and gait apraxia and truncal apraxia/ataxia. Supportive criteria include breathing dysfunction, seizures, spasticity, scoliosis, and growth retardation. The diagnosis of RS is considered tentative until 2 to 5 years of age. The differential diagnosis includes other disorders associated with mental retardation, cerebral palsy, and seizure disorders. These diagnostic criteria for RS should foster reliable communication among investigators and enhance the epidemiological and clinical research of this important disorder.
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PMID:Diagnostic criteria for Rett syndrome. The Rett Syndrome Diagnostic Criteria Work Group. 245 7

We studied 5 boys, 2 to 10 years old, with marked or complete deficiency of hypoxanthine-guanine phosphoribosyltransferase and Lesch-Nyhan syndrome with varying degrees of mental retardation, dysarthria, chorea, dystonia, spasticity, and ataxia. Four patients had marked reduction of homovanillic acid in the cerebrospinal fluid (CSF) and all showed low CSF 3-methoxy-4-hydroxy phenylethylene glycol, indicating reduced dopamine and norepinephrine turnover. Three patients showed high CSF 5-hydroxyindoleacetic acid, suggesting increased serotonin turnover. Some patients improved with carbidopa-levodopa, but others benefited from tetrabenazine, a monoamine-depleting agent. This study provides support for the theory of abnormal central monoamine metabolism in Lesch-Nyhan syndrome.
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PMID:Lesch-Nyhan syndrome: a study of motor behavior and cerebrospinal fluid neurotransmitters. 245 72

Lesch-Nyhan syndrome is a rare X-linked recessive disorder of purine metabolism associated with a virtually complete deficiency of the enzyme hypoxanthine-guanine phosphoribosyl-transferase (HPRT). The disease is characterized by hyperuricemia, self-multilation, choreoathetosis, spasticity, and mental retardation. The abnormalities of purine metabolism are present at birth and may lead to uric acid crystalluria and stone formation early in life. Radiographic findings described in Lesch-Nyhan syndrome include faintly radio-opaque stones on abdominal radiographs or, if renal disease is present, small kidneys with poor function on intravenous urogram. Radiolucent stones are usually composed of uric acid; however, several cases of xanthine and hypoxanthine-containing calculi in Lesch-Nyhan patients receiving allopurinl therapy have also been described. Oxypurine is the collective name for the compounds hypoxanthine, xanthine, and uric acid, and all may be radiolucent. We report a case of Lesch-Nyhan syndrome with presumed renal parenchymal oxypurine deposition demonstrated readily by ultrasonography but not detected on standard radiographs or intravenous urograms.
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PMID:Renal oxypurine deposition in Lesch-Nyhan syndrome: sonographic evaluation. 267 3

Familial spastic paraparesis with amyotrophy of the hands was reported, and its significance in the literature was reviewed. Case 1: An 18 year-old boy, who had been suffering from spastic gait since 12 years old, noticed his hand muscle wasting distributed bilateral first interosseous muscle, thenar and hypothenar muscle at age 17. Case 2: A 20 year-old man, elder brother of case 1, who also walked in spastic manner from his childhood, developed bilateral hand muscle atrophy similar to case 1 at age 19. Clinical features of these two cases could be summarized as familial spastic paraparesis with amyotrophy characterized by hand muscle atrophy, spasticity of lower extremities with hyperreflexia and bilateral positive pathological reflexes and spastic gait. Their younger sister was also examined, who showed only minimal spastic paraparesis. The electrophysiological examination including EMG and SEP suggested the pathological process could involve not only lateral column, but also posterior column and anterior horn. Slight but generalized spinal cord atrophy was demonstrated on metrizamide CT myelography. The muscle biopsy performed from left gastrocnemius in case 2, confirmed neurogenic changes. Although the association of retinal degeneration, cataracta, mental retardation, pes cavus or even generalized amyotrophy has been reported in familial spastic paraparesis, only limited cases are available, dealing with the amyotrophy of limbs. As far the cases with amyotrophy localized to the hands are concerned, it is absolutely rare and only the cases reported by Silver could be regarded as similar or same clinical entities to our cases.
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PMID:[Two cases of familial spastic paraparesis with amyotrophy of the hands]. 267 23

Dopaminergic mechanisms involved in self-inflicting biting behavior (SBB) were investigated in two animal models: monkeys with unilateral ventromedial tegmental (VMT) lesions of the brainstem and rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal dopamine (DA) neurons. The administration of mixed D1/D2 DA agonists to some monkeys with unilateral VMT lesions of the brainstem elicits SBB of the forelimb digits contralateral to the lesion and spasticity of the contralateral hindlimb. This behavior is prevented by pretreatment with the selective D1 antagonist SCH 23390 and with the D1/D2 antagonist fluphenazine. The combined administration of the D1 DA agonist SKF 38393 with the D2 DA agonist quinpirole produces SBB at doses that were ineffective when these drugs were administered individually. The intrastriatal (middle ventrolateral area [MVL]) microinjection of the D1/D2 DA agonist apomorphine (Apo) to rats with unilateral 6-OHDA lesions elicits SBB. This behavior is not prevented by systemic administration of SCH 23390 and partially prevented by the selective D2 antagonist raclopride. However, the combined administration of SCH 23390 and raclopride completely prevents the Apo-induced SBB. Thus, the pharmacological characteristics of the DA agonist-induced SBB in monkeys with unilateral VMT lesions of the brainstem seem to differ from those induced by intrastriatal (MVL area) administration of DA agonists into rats with 6-OHDA lesions of the nigrostriatal DA neurons. The role of DA neuronal systems in the expression of SBB in Lesch-Nyhan syndrome and in some patients with mental retardation, as well as the link between hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency and abnormal dopaminergic function in Lesch-Nyhan syndrome, is discussed.
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PMID:Dopaminergic mechanisms in self-inflicting biting behavior. 269 8

Clinical features of a rare congenital myopathy, muscle-eye-brain (MEB) disease, are described in 19 patients. The pedigree data suggest an autosomal recessive inheritance. The patients presented with congenital hypotonia and muscle weakness. Serum CK was elevated, EMG was myopathic and muscle biopsy showed slight or moderate changes compatible with muscular dystrophy. Ophthalmological findings included severe visual failure and uncontrolled eye movements associated with severe myopia. The flash VEPs were exceptionally high, whereas non-corneal ERG was unrecordable. The EEG showed progressive abnormalities after the age of 6 months. Psychomotor development was slow during the first years of life, and mental retardation was severe. Most patients began to deteriorate around age 5 years. This change included spasticity and joint contractures. CT scans showed ventricular dilatations and abnormally low white matter density in several patients. Spasticity, high VEPs and ocular manifestations differentiate MEB from the Fukuyama type congenital muscular dystrophy.
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PMID:Muscle-eye-brain disease (MEB) 236 Jul 4

This is a presentation and discussion of clinical and laboratory data obtained on 13 girls with Rett syndrome, a progressive neurological disorder. The condition is thought to be far more prevalent than earlier reported. Family history in one patient showed presence of abnormal hand movements, increasing spasticity and psychomotor retardation in a paternal great grandaunt who died at 7 years. In the absence of chromosomal or biochemical markers, the characteristic disorder of hand movements can be used to distinguish this entity from other mental retardation, cerebral palsy and autism conditions. This report addresses the uniformity of clinical expression and highlights the differences between autism and Rett syndrome. Precocious puberty and respiratory alkalosis were not found in our patients. Feeding disorders were commonly present, and are often difficult to manage. The importance of diagnosis is emphasized as it influences long term management.
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PMID:Rett syndrome: studies of 13 affected girls. 308 8

We report on 2 patients, less than age 5 years, and one adult patient with partial duplication 8p, due to interstitial duplication of bands 8p21.1-22. The phenotype in young and adult patients with this chromosomal unbalance syndrome is further documented. In young patients the craniofacial manifestations are very similar to trisomy 8 mosaicism. However, mental retardation is much more pronounced in 8p21-22 duplication than in trisomy 8 mosaicism. The phenotypic changes observed in adult patients are probably secondary and they are due to the great neurologic deficit with generalized spasticity and hypertonia.
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PMID:Partial duplication 8p due to interstitial duplication: inv dup(8)(p21.1----p22). Further delineation of the phenotype from birth to adulthood. 349 29

Of 99 children in the Royal Blind School, Edinburgh (which serves Scotland and part of N E England), 15 had optic atrophy (hydrocephalus 4, intracranial haemorrhage 2, prematurity 2, fetal distress 2, birth asphyxia 2, cerebral atrophy 1, cardiac arrest during hernia operation 1, and leukaemia 1). Fourteen had congenital cataract, 12 congenital retinal aplasia (Leber's congenital amaurosis) and 11 retinopathy of prematurity. There were small numbers in many other diagnostic categories, including three with non-accidental head injury. Mental retardation, spasticity, and nystagmus were frequent other correlates in all diagnostic categories. 'Very probably hereditary' was a conservative attribution in 36, while 'probable' seemed appropriate for 12-that is, almost 48% were hereditary. Only about 11 cases might have been prevented through genetic counselling, which testifies to the frequency of autosomal recessive hereditary disease, although no parents were consanguineous.
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PMID:Blindness in schoolchildren: importance of heredity, congenital cataract, and prematurity. 365 73


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