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Query: UMLS:C0917816 (mental retardation)
 15,867 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pregnant women with untreated phenylketonuria (PKU) with blood phenylalanine levels greater than 1200 mumol/L usually give birth to offspring with congenital birth defects, including microcephaly, cardiac defects and mental retardation. According to Mabry and Levy, hyperphenylalaninaemic (HPA) women with blood phenylalanine levels between 600 and 1200 mumol/L also have an increased risk to their offspring. To study this problem further, the National Institute of Child Health and Human Development has established a collaborative study for 7 years to elucidate a proper treatment programme for these women.
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PMID:Maternal phenylketonuria. 309 85

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.
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PMID:Neonatal screening for metabolic and endocrine diseases. 311 77

The authors report their experience in the systematic, co-ordinated and controlled neonatal screening in France: a coverage of approximately 100 per cent for several years, nearly 13 millions of tests for phenylketonuria and more than 7 millions for hypothyroidism, almost 850 phenylketonuric children and more than 1,600 patients with hypothyroidism, screened and taken care of. The frequency of phenylketonuria is estimated at 1 for 16,394 and the frequency of hypothyroidism at 1 for 4,041. They insist on the need for a strict investigation of false negatives and point out a few specific points on the care of affected children. Overall, the assessment of neonatal screening is positive since it has allowed 2,500 children, doomed to mental retardation, to have a normal growth.
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PMID:[Neonatal screening for phenylketonuria and hypothyroidism in France. A 12-year experience]. 317 78

The literature on maternal phenylketonuria (MPKU) is reviewed in terms of its identification, description, and treatment. A number of professionals have projected a rebound in the frequency of mental retardation associated with PKU since the discovery of MPKU. The lack of knowledge of the exact causal mechanism of the phenomenon and the absence of a consistently effective treatment are emphasized. Evidence gathered regarding the effectiveness of the low phenylalanine diet in the prevention of MPKU is presented, and the implications of this evidence are discussed. Issues surrounding both the phenomenon and possible preventive measures are also discussed. Finally, some questions and responsibilities to be considered by physicians, mental retardation professionals, and policy makers are presented.
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PMID:Maternal phenylketonuria: cause for concern among women with PKU. 331 Jan 39

We have developed classification coefficients and an equation to detect heterozygotes for phenylketonuria. The combination of several variables (Phe, Phe/Tyr, Phe2/Tyr) gave a safe diagnosis in more than 96% of cases. We then computerized a random selection of our population, which was divided into two groups: the first was "selected" to compute discriminant functions, while the second, excluded from computation, was used to check the fitness of our method. Despite the reduction of sample size, 95.2% of unknown subjects were correctly classified. Finally, we used our equation to detect heterozygotes for phenylketonuria in a population of 26 children, affected by non-specific mental retardation, and their mothers. We found a high proportion of carriers for phenylketonuria, defined as subjects having a percent probability of correct classification higher than 90. By this method, heterozygosity was detected in two child-mother couples, four individual children and five mothers.
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PMID:A simplified test to detect PKU heterozygotes by discriminant analysis in mentally retarded children and their mothers. 335 81

Young women with phenylketonuria (PKU) are at risk for bearing children with mental retardation, microcephaly, heart defects, and low birthweight. These effects may be prevented if a low phenylalanine diet is maintained prior to and throughout pregnancy. This report describes the procedures of the New England Regional Maternal PKU Project for identifying and locating this population of at-risk women. Newborn screening records, routine umbilical cord blood screening, and PKU Clinic records provided most of the identifying information. We identified 235 women with hyperphenylalaninemia, ages 12 to 44 years. Of these, 183 had PKU or atypical PKU while 52 had non-PKU mild hyperphenylalaninemia. The 235 women represent 88 per cent of the expected number of women with hyperphenylalaninemia in New England. We identified more than the expected number of those with PKU but only 57 per cent of the expected number with mild hyperphenylalaninemia. Developing a national registry, as well as screening women who utilize birth control clinics or prenatal clinics, may be helpful. Implementing routine umbilical cord blood screening programs may be beneficial in efforts to identify women with hyperphenylalaninemia who have had a child and may want more children in the future.
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PMID:The New England Maternal PKU Project: identification of at-risk women. 338 53

Experimental hyperphenylalaninemia has been induced in 5-day-old chicks by dietary treatments with phenylalanine and alpha-methylphenylalanine. An increase of nearly 8-fold in plasma Phe/Tyr ratio was found after 4 days of supplementation the standard diet with 5% phenylalanine plus 0.4% alpha-methylphenylalanine. The increase in this ratio was about 13-fold after 9 days of the same treatment. Similar results were observed in brain and liver, although the increases were smaller than those found in plasma. Total body, brain and liver weight decreased after 9 days of treatment. Phenylalanine plus alpha-methylphenylalanine administration to 5-day-old chicks produced a significant decrease in the 3-hydroxy-3-methylglutaryl-CoA reductase and mevalonate-5-pyrophosphate decarboxylase specific activities from both brain and liver. These results demonstrated for the first time that experimental hyperphenylalaninemia inhibited different enzyme activities directly implicated in the regulation of cholesterogenesis. Therefore, a reduced cholesterol synthesis in brain may evidenciate the theory of an impaired myelination leading to mental retardation in phenylketonuria patients.
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PMID:Inhibition of brain and liver 3-hydroxy-3-methylglutaryl-CoA reductase and mevalonate-5-pyrophosphate decarboxylase in experimental hyperphenylalaninemia. 340 80

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.
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PMID:Neonatal screening for metabolic and endocrine disorders. 348 2

Pregnant rats injected with phenylacetate produced pups who had structurally abnormal cortical pyramidal cell dendrites. Neurons whose perikarya were in layer 5 had apical dendritic arbors with reduced numbers of dendritic spines which were longer and thinner than controls. Pyramidal cells of other cortical layers, as well as hippocampal pyramidal cells, were qualitatively and quantitatively normal. These results may be pertinent to children born to mothers with hyperphenylalaninemia (untreated PKU), many of whom have microcephaly, seizures and mental retardation. Application of findings in this rat model of maternal PKU to affected human children is uncertain until human histologic data become available.
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PMID:Cortical dendritic spine loss in rat pups whose mothers were prenatally injected with phenylacetate ('maternal PKU' model). 370 82

A 16-year-old boy with classical phenylketonuria (PKU) and mild mental retardation (IQ 69) was detected by the screening of mentally retarded school children in Taiwan with Guthrie's bacterial inhibition assay. The follow-up family study showed that one of his married elder sisters suffered from borderline mental retardation (IQ 75) and was also diagnosed as a classical case of PKU. She had borne one boy and one girl, both suffering from mild mental retardation, microcephaly, delay in linguistic development and severe growth retardation. This is the first known Chinese family with maternal PKU. To prevent future mental retardation caused by maternal PKU, the simultaneous establishment of a register system with a neonatal screening programme, is indicated for the follow-up of PKU girls, screening of the whole family of newly discovered PKU cases, and to exclude unrecognized maternal PKU in women who have given birth to a microcephalic child.
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PMID:A Chinese family with phenylketonuria and maternal phenylketonuria detected by family screening. 379 88


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