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

In galactosemia, prevention of mental retardation depends on early recognition of the disorder and institution of dietary restriction of galactose. We describe an automated fluorometric micromethod for galactose in whole blood spotted on filter paper. Galactose is oxidized by galactose oxidase to D-galacto-hexadialdose and H2O2 and measured as the highly fluorescent condensation product of homovanillic acid formed when H2O2 is acted upon by horseradish peroxidase. The procedure is 10-fold more sensitive than colorimetric procedures for galactose and is not hampered by the nonspecific fluorescence from endogenous NADPH that is encountered in methods in which galactose dehydrogenase is used. At a sampling rate of 40/h with a sample-to-wash ratio of 1/2, carryover is negligible, reproducibility is excellent, and 80% of steady state is achieved. Analytical recovery of added galactose was 95%. The method has the requisite sensitivity and accuracy for quantification of galactosemia and galactosuria in milkfed newborn infants and genetic evaluation of families of patients.
 ...
PMID:Automated fluorometric analysis of galactose in blood. 87 Feb 60

Galactosemia in newborns and infants is associated with the following symptoms: jaundice, hepatomegaly, failure to thrive, feeding difficulties, hypoglycemia, convulsions, lethargy, amino-aciduria, cataracts, hepatic cirrhosis, ascites, and mental retardation. If the preliminary evaluation indicates galactosemia, there is high risk for E. coli sepsis and death. Strong consideration should therefore be given for early antibiotic therapy in infants with suspected galactosemia in spite of the absence of clinical signs or symptoms of sepsis.
 ...
PMID:Association of Escherichia coli sepsis and galactosemia in neonates. 156 28

Governmental officials as well as medical scientists in Taiwan have worked hard in recent years to develop and to implement various measures, such as prenatal diagnosis and neonatal screening, to lower the incidence of hereditary diseases and mental retardation in the population. An inquiry into the possibility of devising a chromosomal and biochemical screening program and to apply it routinely to all the mentally retarded school children island-wide was the major aim of the present study. A collection of 1,614 blood samples was screened for phenylketonuria (PKU), galactosemia, homocystinuria, biotinidase deficiency, and congenital hypothyroidism. The IQ of these children ranged from 50-75 (1,397 children, moderate group) to less than 50 (217 children, severe group). Six cases of PKU (one tetrahydrobiopterin deficient and five classical) and three cases of thyroid dysfunction were found. The overall incidence of these two diseases was 0.56%. Of the 1,614 blood samples, 1,323 were cultured and karyotyped successfully. One hundred and twenty-five of them had chromosome abnormalities. The majority (64 out of 125) were trisomy 21. A remarkable difference in the percentage of mentally retarded children with chromosome abnormalities was observed between the moderate (7.87%) and severe (17.51%) retarded.
 ...
PMID:Chromosomal and biochemical screening on mentally retarded school children in Taiwan. 175 40

We describe the molecular characterization of two mutations responsible for galactosemia, an inherited disorder of galatose metabolism that causes jaundice, cataracts, and mental retardation in humans. The coding region of galactose-1-phosphate uridylyltransferase (GALT; UDPglucose:alpha-D-galactose-1-phosphate uridylyltransferase, EC 2.7.7.12) was amplified by the polymerase chain reaction from total cDNA of a classic galactosemic individual and was characterized by direct sequencing of the products. Two missense mutations were identified: (i) replacement of valine-44 by methionine and (ii) replacement of methionine-142 by lysine. These mutations led to a drastic reduction in GALT activity when individual mutant cDNAs were overexpressed in a mammalian cell system, although full-length protein is synthesized in this assay. The two galactosemia mutations account for 3 of the 15 galactosemia alleles analyzed. These results suggest that galactosemia is caused by a variety of mutations, which might be responsible for the observed clinical heterogeneity of this disorder. We also present the molecular characterization of two GALT polymorphisms: (i) replacement of leucine-62 by methionine and (ii) replacement of asparagine-314 by aspartate. It appears that galactosemia mutations tend to occur in regions that are highly conserved throughout evolution while the polymorphisms change variable residues.
 ...
PMID:Molecular basis of galactosemia: mutations and polymorphisms in the gene encoding human galactose-1-phosphate uridylyltransferase. 201 74

Nutritional approaches are available for the management of several different classes of inborn metabolism errors. In phenylketonuria (PKU), phenylalanine is not properly metabolized; and its accumulation leads to neurologic dysfunction and metal retardation. Altering the diet to limit phenylalanine intake led to remarkable improvement in children with PKU. It was later found that instituting dietary therapy immediately after identification of the disorder in newborns prevented mental retardation. Throughout the 1960s nutritional therapies were found for other inborn disorders, including galactosemia, maple syrup urine disease, and homocystinuria. For the group of disorders associated with defects in the urea cycle, leading to profound hyperammonemia, therapy based on the concept of waste nitrogen excretion (i.e., by increasing excretion of urea cycle intermediates in the urine, nitrogen that would otherwise recycle as ammonia can be eliminated) dramatically produced better control of hyperammonemia and its consequences. Some inborn errors of metabolism respond to vitamin therapy. Biotin-related multiple carboxylase synthetase deficiency can be produced by either of two enzyme defects--holocarboxylase synthetase deficiency or biotinidase deficiency. Both are treatable with biotin supplementation. The symptoms of multiple carboxylase deficiency can also occur after intestinal resection or ingestion of raw eggs. Multiple carboxylase deficiency has been treated successfully in utero by giving the mother biotin supplements. Peroxisomal disorders may respond to dietary management. Liver disease in hereditary tyrosinemia may be accentuated by hypermethioninemia and treated by controlling the blood methionine level. Glycogen storage disease Type I, which causes hypoglycemia, can be controlled by oral administration of cornstarch.
 ...
PMID:Nutritional therapy for selected inborn errors of metabolism. 268 28

Five-hundred and fifty one mentally retarded children from seven institutes in Northern Taiwan were screened by dried blood spot for the detection of treatable congenital metabolic diseases, including congenital hypothyroidism, phenylketonuria, homocystinuria, maple syrup urine disease and galactosemia. We found 2 children (0.36%) with congenital hypothyroidism, 1 case (0.18%) of classical phenylketonuria and two cases (0.36%) of trisomy 21 associated with autoimmune thyroiditis. The results of our investigation suggest that congenital hypothyroidism and phenylketonuria can be the factors causing mental retardation among children in Taiwan and mass neonatal screening of these treatable inborn metabolic diseases is strongly indicated for efficiently circumventing mental retardation in our community.
 ...
PMID:Screening of congenital hypothyroidism, phenylketonuria, galactosemia, homocystinuria, and maple syrup urine disease in moderate to severe mentally retarded Chinese children. 278 33

The screening of neonates for metabolic diseases is important in order to identify a population with or at risk for metabolic diseases. Early diagnosis can then be made, treatment instituted and physical and/or mental handicaps due to the disease can be prevented. The World Health Organization's screening criteria are helpful in selecting those diseases appropriate for screening. Usually a state-designated central laboratory performs the screening tests. All states screen for phenylketonuria (PKU) and hypothyroidism; in addition, 26 states screen for galactosemia, 20 for maple syrup urine disease and 19 for homocystinuria. The cost-benefit ratio for screening programs is excellent, varying from 1:13 to 1:20. The necessary follow-up of patients for diagnosis and treatment can be enhanced by maintaining a close liaison with the laboratory and providing adequate information to parents. As a result of instituting a screening program, the incidence of mental retardation due to PKU has been practically eliminated and new insights about metabolic diseases have been obtained. The rapid progress in technology may soon result in better and cheaper tests capable of identifying more diseases amenable to treatment.
 ...
PMID:Neonatal screening for metabolic and endocrine diseases. 311 77

The impact of metabolic diseases (inborn errors of metabolism) and endocrine disorders in pediatrics has markedly increased during the last few decades. Critical periods in the development of the central nervous system need special attention in children with these disorders. Early diagnosis and treatment are important in order to prevent mental retardation and serious handicaps in some of these patients. Certain patients with metabolic and endocrine disorders lack early clinical symptoms or have so non-specific signs that permanent neurological handicaps are present when the patients are finally diagnosed. One way to identify these patients is by means of mass screening. A blood sample is then collected from every newborn infant and analyzed for abnormal levels of metabolites or hormones. It is possible to detect at least thirty different disorders in this way. In most European countries screening programmes involve phenylketonuria (PKU) and congenital hypothyroidism. The prognosis for these patients has improved dramatically after the introduction of screening. The Swedish neonatal metabolic screening programme was started in 1965 by screening for PKU. Subsequently, screening for galactosemia and congenital hypothyroidism was added. The result of the screening programme 1965-1985 is as follows: (table; see text) The main benefit of early detection and treatment of children with PKU, congenital hypothyroidism and galactosemia is the prevention of mental retardation and other handicaps. Recently nationwide pilot screening for congenital adrenal hyperplasia (adrenogenital syndrome) was started.
 ...
PMID:Neonatal screening for metabolic and endocrine disorders. 348 2

The Austrian Screening Program examined during 12 years 1,002.424 newborns and uncovered 23 cases of Galactosemia by Transferase deficiency, 6 by Kinase deficiency as well as 1 case of Phosphoglucomutase deficiency, 1 of porto-caval shunt and 1 congenital liver cirrhosis. Among the 23 Transferase deficiencies 18 took a fulminating course and 8 of these died. Since introduction of exchange transfusion as emergency treatment and acceleration of the screening procedure only 2 among 11 have died. Half of all Galactosemia cases, Transferase and Kinase, show already at the first examination (2. week) a cataract which however is reversible. In contrast to Kinase deficiency all cases of Transferase deficiency exhibit mental retardation if they grow older. Since treatment is early (9, 7 days), easy and the IQ already at 4 years 10 points below that of treated PKU's of same age a congenital brain damage has to be considered. Galactosemia by Transferase deficiency is in Western-Austria significantly more frequent than in Eastern-Austria. 17 boys compare with 6 girls. Among 6 cases of Galactosemia by Kinase deficiency 1 belonged to a Gippsy and 2 to Yugoslavian guest worker families. The 23 cases with Transferase deficiency had 45 siblings among whom 11 also were galactosemic. In 8 sibships the clinical course was of the same typ, but in 1 family one child showed the fulminating the other the subacute course.
 ...
PMID:[Hypergalactosemia in newborns as uncovered by the Austrian screening program in 12 years (author's transl)]. 645 54

Two siblings with classic transferase deficiency galactosemia that was detected at birth have been treated with lactose restriction since the neonatal period. Both patients developed a unique and progressive neurologic syndrome of mental retardation, tremor, and ataxia. Careful review of the family history and medical records, the absence of metabolic disturbances other than those related to galactosemia, and the aggregate physical findings and neurodiagnostic studies ruled out other neurologic disorders in these siblings. It is therefore proposed that these patients represent a subgroup of transferase-deficient galactosemic patients, who develop characteristic neurologic sequelae with conventional dietary management. The existence of this subgroup should be considered in evaluations of therapeutic responses in cohorts of patients with galactosemia. Further, galactosemia should be included in the differential diagnosis of tremor and ataxia in the setting of mental retardation.
 ...
PMID:Curious neurologic sequelae in galactosemia. 670 Oct 54


1 2 3 4 Next >>