Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hallervorden-Spatz disease is a rare, autosomal-recessive hereditary condition characterized by early onset of progressive movement alterations such as dystonia, rigidity, and choreoathetosis, which is usually associated with pyramidal signs and mental deterioration. The authors report two cases for which diagnosis of Hallervorden-Spatz disease was based on clinical manifestations that appeared during the first year of life, illness progression, and late-stage magnetic resonance imaging findings. The possibility that these two cases, along with other previously described rare instances with similar clinical features, be considered as a variant of subtype of the early-onset type of Hallervorden-Spatz disease is suggested. The need to differentiate these cases from cases of static encephalopathy with mental retardation and motor impairment is also stressed.
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PMID:Hallervorden-Spatz disease: two new early childhood onset cases. 1064 7

Primary dystonias are movement disorders with dystonia as a major symptom. They are frequently inherited as Mendelian traits. There are at least eight clinically distinct autosomal dominant and two X-linked recessive forms. In addition, pedigree analyses suggest the occurrence of an autosomal recessive variant. The clinical classification is increasingly being replaced by a genetic one. To date gene loci have been identified in at least six autosomal dominant forms, i.e., in idiopathic torsion dystonia (9q34), focal dystonia (18p), adult-onset idiopathic torsion dystonia of mixed type (8p21-q22), dopa-responsive dystonia (14q22.1-q22.2), and paroxysmal dystonic choreoathetosis (2q25-q33; 1p21-p13.3). Gene loci in the X-linked recessive forms have been assigned to Xq13.1 in the X-linked dystonia parkinsonism syndrome and to Xq22 in X-linked sensorineural deafness, dystonia, and mental retardation. The disease genes have been identified in two autosomal dominant forms and in one X-linked recessive form. Mutations in a gene coding for an ATP-binding protein were detected in idiopathic torsion dystonia (DYT1), and the GTP cyclohydrolase 1 gene is mutated in dopa-responsive dystonia (DYT5). In sensorineural deafness, dystonia, and mental retardation, mutations were found in the gene DDP coding for a polypeptide of unknown function. This article reviews the clinical and molecular genetics of primary dystonias, critically discusses present findings, and proposes referring to the known forms, most of which can be distinguished by genetic criteria, as dystonias 1-12.
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PMID:Clinical and molecular genetics of primary dystonias. 1073 19

Lesch-Nyhan syndrome is a genetic disorder resulting in hyperuricemia, choreoathetosis, mental retardation, and self-mutilation. The most salient feature of this disorder is the self-injurious behavior (SIB). Although the utility of behavioral interventions with SIB has been well documented, behavioral interventions with Lesch-Nyhan syndrome have been limited in number and long-term success. This article reviews the behavioral treatments that have been used in treating individuals with Lesch-Nyhan syndrome and discusses the strengths and weaknesses of these methods. Suggestions for future directions in the use of behavioral interventions for controlling SIB in Lesch-Nyhan syndrome are provided.
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PMID:A review of behavioral treatments used for Lesch-Nyhan syndrome. 1080 80

Pathology and associated clinical symptoms of hereditary dentatorubral-pallidoluysian atrophy (H-DRPLA) which was established as a new inherited neurodegenerative disease in 1982 are described. Obligatory lesions in the central nervous system combine with degeneration of the dentatorubral and pallidoluysian pathway, and occasional degenerative lesions are found in the cerebral white matter, putamen, Goll's nucleus of the medulla oblongata, and lateral corticospinal and Goll's tract of the spinal cord. The main clinical symptoms are myoclonus, epilepsy, dementia or mental retardation, cerebellar ataxia and choreoathetosis. Furthermore, newly developing aspects in the pathology of H-DRPLA following the discovery of the gene locus of H-DRPLA in 1994 are briefly described.
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PMID:Hereditary dentatorubral-pallidoluysian atrophy. 1103 86

Lesch-Nyhan syndrome is a rare genetic disorder characterized by mental retardation, self-mutilation, choreoathetosis, and hyperuricemia. The disease is caused by a mutation in the hypoxanthine-guanine phosphoribosyltransferase gene and is transmitted as a sex-linked recessive disorder. Since hyperuricemia is the primary metabolic problem caused by a hypoxanthine-guanine phosphoribosyltransferase mutation, urologic evaluation and treatment is often necessary for children with this disease. We report a 3-year-old boy who presented with anuric renal failure secondary to bilateral obstructing uric acid calculi. The evaluation of T lymphocytes revealed a hypoxanthine-guanine phosphoribosyltransferase mutation consistent with Lesch-Nyhan syndrome. The diagnosis and urologic management of this disorder is discussed.
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PMID:Lesch-Nyhan syndrome presenting as acute renal failure secondary to obstructive uropathy. 1111 62

The enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) catalyzes the reutilization of hypoxanthine and guanine to the purine nucleotides IMP and GMP, respectively. HPRT deficiency is an X-linked disorder characterized by uric acid overproduction and variable neurologic impairment. The complete deficiency of HPRT is diagnostic of Lesch-Nyhan syndrome manifested by choreoathetosis, spasticity, mental retardation, and self-injurious behavior. In some HPRT-deficient patients the enzyme defect appeared to be "partial" and the neurologic symptoms mild to severe (Kelley-Seegmiller syndrome). This has prompted the classification of HPRT deficiency in 2 distinct groups: Lesch-Nyhan syndrome and Kelley-Seegmiller syndrome, which has created much confusion. A spectrum of clinical consequences of HPRT deficiency has been recognized in small series of patients, but the complete spectrum of the neurologic disorder has not been described in a single series of patients examined by the same observers. We analyzed our experience with 22 patients belonging to 18 different families with HPRT deficiency diagnosed at "La Paz" University Hospital in Madrid over the past 16 years. The clinical spectrum of these HPRT-deficient Spanish patients was similar to the different phenotypes occasionally reported in the literature, in some cases diagnosed as Lesch-Nyhan "variants." The clinical, biochemical, enzymatic, and molecular genetic studies on these 22 patients allowed us to delineate a new classification of HPRT deficiency. Based on the neurologic symptoms, dependency for personal care, HPRT activity in hemolysate and in intact erythrocytes, and predicted protein size, patients were classified into 4 groups: Group 1 (2 patients), normal development with no neurologic symptoms, HPRT activity was detectable in hemolysates and in intact erythrocytes, and the mutation did not affect the predicted protein size. Group 2 (3 patients) mild neurologic symptoms that did not prevent independent lives, HPRT activity was detectable in intact erythrocytes, and the protein size was normal. Group 3 (2 patients), severe neurologic impairment that precluded an independent life, no residual HPRT activity, and normal protein size. Group 4 (15 patients), clinical characteristics of Lesch-Nyhan syndrome (some may not show self-injurious behavior), no residual HPRT activity, and in most (7 of 8 patients in whom the mutation could be detected) the mutation affected the predicted protein size. This classification of HPRT deficiency into 4 groups may be more useful in terms of accuracy, reproducibility, assessment for treatment trials and prognosis. The study of this Spanish series allows us to conclude that HPRT deficiency may be manifested by a wide spectrum of neurologic symptoms; the overall severity of the disease is associated with mutations permitting some degree of residual enzyme activity; and mutation analysis provides a valuable tool for prognosis, carrier identification, and prenatal diagnosis.
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PMID:The spectrum of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Clinical experience based on 22 patients from 18 Spanish families. 1130 86

Kernicterus (bilirubin encephalopathy) is a disease entity with a very high rate of mortality in neonates. The children who survive are left with neurological deficits such as choreoathetosis, sensorineural deafness and mental retardation. Magnetic resonance imaging of the brain in this condition has specific findings which aid in the accurate diagnosis of the condition, along with clinical and biochemical criteria. Reports have shown involvement of the globus pallidus, putamen, and less commonly the thalamus. More specific involvement may be isolated lesions of the globus pallidus. Magnetic resonance imaging has shown a good sensitivity in this condition.
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PMID:MRI in kernicterus. 1258 Oct 55

Various enzyme defects in the metabolic pathways of purines and pyrimidines are known, which result in different diseases occurring in children. They mainly affect kidney function, central nervous system, immunological and blood system. For example, complete deficiency of HPRT (hypoxanthine-guanine-phosphoribosyl-transferase) causes the Lesch Nyhan syndrome, which is characterized by hyperuricemia, mental retardation, choreoathetosis and compulsive self-mutilation. XDH deficiency (xanthine-dehydrogenase) causes in arthropathia and myopathia. For screening for these and other enzyme defects, urinary purine and pyrimidine excretion is considered a simple diagnostic tool. The purpose of the present study was to establish a reverse phase HPLC screening method for urinary purines and pyrimidines and to establish age related reference ranges in children for the urinary excretion of orotic acid, uracile, pseudouridine, uric acid, hypoxanthine, xanthine, thymine, 7-methylguanine, inosine, guanosine and adenosine.
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PMID:Purine and pyrimidine metabolites in children's urine. 1292 81

Lesch-Nyhan syndrome (LN) is a severe X-linked disorder of males characterized by hyperuricaemia, choreoathetosis, spasticity, mental retardation and self-mutilation. The disorder is caused by a wide spectrum of mutations distributed throughout the hypoxanthine phosphoribosyltransferase (HPRT) gene. Female carriers of LN display no clinical symptoms but are at 50% risk of passing on the affected gene to their male offspring. A couple who had a boy with LN were referred to Monash IVF for preimplantation genetic diagnosis (PGD) because the woman had undergone tubal ligation and the couple wanted to have another child. A test was developed for the causative mutation IVS8+6 T-->G mutation based on minisequencing primer extension that also incorporated the co-analysis of an informative tetranucleotide marker in intron 3 of the HPRT gene to identify allelic dropout. All four biopsied embryos from their first IVF cycle were diagnosed as unaffected, and transfer of two embryos in the cohort with the highest morphological quality resulted in a singleton pregnancy and the birth of a healthy girl. Direct mutation detection by mini-sequencing and parallel analysis of an informative linked marker provides an alternative strategy for molecular diagnosis of point mutations that will have useful application in PGD for other single gene disorders.
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PMID:Preimplantation diagnosis of Lesch-Nyhan using mini-sequencing primer extension. 1465 97

Two children with mental retardation, choreoathetosis, dystonia, and muscle rigidity are reported. They had a history of severe hyperbilirubinemia after birth as a result of Rh isoimmunization. The history and clinical picture suggested the diagnosis of kernicterus. The magnetic resonance imaging examination showed a bilateral signal intensity increase in the globus pallidus on T2-weighted images. Additionally, our patients showed symmetric bilateral hyperintensity and volume loss in the hippocampus, which is known to be another characteristic area of bilirubin deposition in kernicterus.
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PMID:Bilateral mesial temporal sclerosis and kernicterus. 1509 Nov 33


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