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)

A clinical and genetic study of congenital myotonic dystrophy in Britain has been carried out in 70 patients from 54 sibships. The clinical aspects are analysed here, and the existence of a syndrome clinically distinct from myotonic dystrophy of later onset is confirmed. Characteristic features included neonatal hypotonia, motor and mental retardation, and facial diplegia. A high incidence of talipes occurs at birth together with hydramnios and reduced fetal movements during pregnancy, factors suggesting prenatal onset of the disorder in many cases. Prolonged survival is the rule after infancy, but the occurrence of numerous neonatal deaths in the sibships suggests the existence of unrecognized cases dying in the neonatal period.
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PMID:Congenital myotonic dystrophy in Britain. I. Clinical aspects. 110 35

Observations relating to 18 cases of the neonatal form of myotonic dystrophy are described. These consisted of 9 cases of severe forms incompatible with survival, characterised by major respiratory disorders, hypotrophia and difficulty in swallowing, associated with a facial diplegia and pes equinus. The other 9 patients suffered from more moderate, not lethal forms. In addition to muscular troubles manifested by precocious hypotonia, the disease involved serious mental retardation. The absence of myotonia was constant in the very young infants. Anomalies in pregnancies resulting in the birth of children suffering from a neonatal form of myotonic dystrophy are analysed and their frequency is emphasized. From the genetic point of view, the elective transmission of myotonic dystrophy by the mothers was found in all the cases. The knowledge of neonatal forms must be taken into consideration for genetic counseling.
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PMID:[Clinical and genetic aspects of the early form of Steinert's dystrophia myotonica]. 121 49

The authors studied from several points of view 10 patients suffering from a neo-natal form of Steinert's disease. They analyse the variety of the family histories, of dysembryoplastic symptoms, of neo-natal difficulties and the subsequent impairment of mental development. They could not find any correlation between this latter evolution and the severity of the neurological damage, judged by the mentioned symptoms. They conclude that the mental retardation is proportional to the low quality of the early socio-emotional environment and believe that this hypothesis is confirmed by the fact that maxillo-facial malformations are mocise speech and mimicry in their early childhood.
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PMID:[A multidisciplinary study of infantile Steinert's syndrome]. 121 50

We studied seven children with congenital myotonic dystrophy, aged 2.1-8.3 years, and the results of computed tomography and magnetic resonance imaging of the brain were analyzed and neurological development was assessed from the neonatal period. We found that ventricular dilatation that had been seen on the first day of life in two of three infants had not progressed in sequential follow-up computed tomography scans taken at intervals of one to six years. Also, in T2-weighted magnetic resonance imagings, areas of periventricular hyperintensity were identified in all children, as well as areas of subcortical hyperintensity in one child. Further, an asphyxial episode had occurred at birth in five patients and the extent of the periventricular hyperintensity was found to correlate significantly with Apgar scores, indicating that the degree of perinatal asphyxia that had occurred was responsible for the abnormalities uncovered by the magnetic resonance imagings. However, there was no correlation between the neurodevelopment outcome and the extent of the periventricular hyperintensity or ventriculomegaly. Therefore, in patients with congenital myotonic dystrophy, a neonatal episode of asphyxia can be responsible for a finding of periventricular hyperintensity, but it is unlikely that an integral part of the mental retardation is attributable to brain damage due to perinatal asphyxia.
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PMID:Neuroradiological findings in children with congenital myotonic dystrophy. 139 86

We describe the maternal and neonatal complications of pregnancy in two patients with myotonic dystrophy. The disease leads to an increased spontaneous abortion rate, hydramnios, prolonged first and second stages of labour, retained placenta, postpartum haemorrhages and anaesthetic sensitivity in the mother. The neonatal problems are caused by the congenital form of the disease. The major clinical features of congenital myotonic dystrophy are bilateral facial weakness, hypotonia, neonatal distress, feeding difficulties, talipes, tent-shaped mouth, mental retardation and delayed motor development. Relatives of a known myotonic dystrophy patient should be advised to let themselves be examined for this disease. If the disease is diagnosed, information should be given regarding possibilities for prenatal diagnosis. Pregnancy in myotonic dystrophy patients should be monitored by a gynaecologist. Labour has to take place in a hospital with intensive care facilities for mother and child.
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PMID:[Dystrophia myotonica and pregnancy]. 146 72

Increasingly, human genes are being identified by the "reverse genetics", or "positional cloning" approach. This molecular genetic strategy is particularly useful in mental illness, for which no readily detectable functional alterations are present to indicate candidate genes. The positional cloning procedure is briefly described. Significant examples of successful positional cloning are presented, including the fragile-X mental retardation syndrome gene. The study of gene expression may be complicated by genetic and non-genetic variability. Genomic imprinting may play a role in several mental illnesses, and may provide an explanation for the unusual inheritance pattern in fragile-X syndrome, for the phenotypic differences observed between Angelman and Prader-Willi syndromes, and for the juvenile onset form of Huntington disease. DNA instability may explain disease anticipation in fragile-X syndrome and myotonic dystrophy. Finally, the prospects of improvements in positional cloning methods for tracking genes responsible for mental illness are briefly discussed.
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PMID:Tracking disease genes by reverse genetics. 149 55

Myotonic dystrophy is a well recognised and well defined multisystem disorder which is inherited in an autosomal dominant fashion through a locus on chromosome 19. The disease itself is characterised by rigidity and degeneration of skeletal muscle, cataract formation, gonadal atrophy, frontal baldness and mental retardation. Like many inherited disorders there is a variable expression and so diverse clinical presentations can occur.
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PMID:Could it be myotonic dystrophy? Myotonic dystrophy presenting with atrial flutter. 149 7

Fragile-X syndrome, the most common inherited form of mental retardation, has a very unusual mode of inheritance. The disease is caused by a multistep expansion, in successive generations, of a polymorphic CGG repeat localized in a 5' exon of FMR-1, a gene of unknown function. Two main mutation types have been categorized. Premutations are moderate expansions of the repeat and do not cause mental retardation. Full mutations are found in affected individuals and involve larger expansions of the repeat, with abnormal methylation of the neighboring CpG island. The full mutations demonstrate striking somatic instability and extinguish expression of FMR-1. Premutations are changed to full mutation only when transmitted by a female with a frequency that increases up to 100% as a function of the initial size of the premutation. Direct detection of the mutations provides an accurate test for pre- and postnatal diagnosis of the disease, and for carrier detection. A similar unstable expansion of a trinucleotide repeat occurs in myotonic dystrophy.
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PMID:Molecular genetics of the fragile-X syndrome: a novel type of unstable mutation. 150 17

The concept of anticipation, the occurrence of a genetic disorder at progressively earlier ages in successive generations, has been debated from the early years of this century, with myotonic dystrophy as the most striking example. Throughout most of this period there has been controversy as to whether the phenomenon resulted from observational and ascertainment biases or reflected a more fundamental mechanism. The recent discovery of inherited unstable DNA sequences, first in fragile-X mental retardation and now in myotonic dystrophy, not only confirms that anticipation indeed has a true biological basis but provides a specific molecular mechanism for it; this discovery can explain many of the puzzling anomalies in the inheritance of myotonic dystrophy and may prove relevant to comparable problems in other genetic disorders.
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PMID:Anticipation in myotonic dystrophy: new light on an old problem. 160 89

An 11-year-old girl with congenital myotonic dystrophy and infantile autism was reported. Her mother also suffered from typical myotonic dystrophy. Since her birth, the patient had been floppy, and showed bilateral talipes equinus at 1 year of age. Her subsequent psychomotor and speech development has been retarded. She showed autistic behavior and persistence to the sameness before 2 years old. She was admitted to Sawarabien at the age of 10 years. She could not talk anything but could understand simple, oral messages. Although she had severe degree of mental retardation, her ability for matching figures was relatively well reserved. Her autism was so manifest that it could not be explained by the degree of mental retardation. Neurological examinations revealed that she had facial diplegia, inverted V-shaped mouth, high-arched palate, talipes equinus, percussion myotonia of the tongue, generalized muscular atrophy and weakness, lordosis, areflexia, and congenital cataracta. The serum CPK was slightly elevated. EMG showed a myopathic pattern but did not show any myotonic discharge yet. The brachioradial muscle was biopsied and examined by light- and electron-microscopy. It mainly showed mild varieties of muscle fiber diameter and internal nuclei. Ultrastructurally, irregularly indented central nuclei and perinuclear degeneration of myofibrils associated with secondary lysosomes, lipid droplets and glycogen granules were revealed. Ventricular dilatation and some dysfunction of the brain were also revealed by CT scan and EEG respectively. The present case suggests that congenital myotonic dystrophy can be added into the disease group associated with infantile autism.
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PMID:[A case of congenital myotonic dystrophy with infantile autism]. 278 60


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