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

Untreated maternal phenylketonuria (PKU) may result in nonphenylketonuric offspring with mental retardation, microcephaly, congenital heart disease, and low birth weight. We obtained information about 34 pregnancies in which dietary therapy was instituted to lower the concentration of phenylalanine in maternal blood in an attempt to avoid fetal damage. The outcomes varied from mental normality with no evidence of fetal effect to neonatal death due to congenital heart disease. Dietary therapy with control of the maternal biochemical abnormalities is not yet of proved efficacy in preventing these fetal effects. The available data tend to support initiation of dietary therapy prior to conception for best results, but the number of cases is small and points to the need for further research.
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PMID:Maternal phenylketonuria--results of dietary therapy. 705 57

A simple enzyme-multiple auxotroph assay has been developed for the identification of newborn infants with several of the inherited metabolic defects in the Krebs cycle for the detoxification of ammonia and in the ornithine metabolic pathway. This mass screening test is used with dried filter paper blood specimens and can easily be added to existing multiple testing programs presently used in screening for phenylketonuria or congenital hypothyroidism. This assay can be used to detect patients with citrullinemia, argininosuccinic acid lyase deficiency, and argininemia. In addition to these urea cycle disorders, the several types of ornithinemia, which can result in gyrate atrophy of the retina or mental retardation, should be detectable with this assay. The strengths and weaknesses of this assay are discussed and a large-scale pilot screening trial is proposed.
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PMID:A neonatal screening test for argininosuccinic acid lyase deficiency and other urea cycle disorders. 712 51

Maternal hyperphenylalaninemia constitutes a potential hazard to the fetus for whom the risks of postnatal mental retardation, microcephaly, and congenital malformations are elevated. Preconception and intragestational dietary treatment can apparently improve the outcome of such pregnancies. In the absence of predictive mechanisms for pregnancies at risk and preventive measures involving reproductive counseling and treatment, there could be a rebound in the population frequency of mental retardation related to disorders of phenylalanine metabolism in subsequent generations. We describe a program serving a population of six million that includes screening, diagnosis, treatment, and counseling of the hyperphenylalaninemias. The program has recently added a simple dedicated register for males and females with hyperphenylalaninemia to supplement traditional methods for continuous surveillance of probands. We registered 153 patients: 43 females and 56 males with phenylketonuria, 23 females and 31 males with benign hyperphenylalaninemia, of which 22, 7, 27 and 5, respectively, had reached their 12th birthday in an 1981. Regional centers in the program provided counseling about the consequences of maternal hyperphenylalaninemia and the options to prevent them. No family has rejected the principle or fact of the Register and its goals.
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PMID:Prevention of mental retardation in offspring of hyperphenylalaninemic mothers. 713 36

Although the enzymatic etiology and the link between this and the accumulation of phenylalanine and its metabolites in phenylketonuria has been amply established, the pathogenesis of the brain dysfunction accompanying this inherited metabolic disease is still under research. Effects of phenylalanine and its metabolites, some leading to irreversible defective structural features in the nervous system, and others to reversible defective neurotransmission, are described as responsible of the mental retardation and other neurological and behavioural symptoms characteristic of phenylketonuria.
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PMID:[Pathogenesis of cerebral dysfunction in phenylketonuria]. 714 76

The present decade marks the end of a unique generation--when the public benefited from the prevention of mental retardation phenylketonuria (PKU) without having to deal fully with the problems which can be anticipated from the reproduction of successfully treated, phenylketonuric individuals. The dysgenic effect (increase in prevalence of the PKU gene) from this reproduction will have negligible influence on the frequency of mental retardation from PKU over the next few centuries. In contrast, a dysgenic effect from maternal PKU will cause a rebound in frequency of mental retardation within this decade. Failure of the PKU programs as a result of maternal PKU, could affect the public attitude toward programs for the study and prevention of mental retardation and genetic diseases. Minimizing and explaining the rebound in frequency of mental retardation will be a difficult but necessary task for workers in the field of mental retardation.
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PMID:Projections of a rebound in frequency of mental retardation from phenylketonuria. 714 8

Recent work has shown that in phenylketonuria, PKU, in which phenylalanine accumulates in the blood, the damage to the brain, which so often leads to mental retardation, is not solely due to the large quantities of phenylalanine that enter the brain. The raised levels of phenylalanine in the blood lead to a partial exclusion of various other amino acids from the brain and this exclusion in itself damages the brain. Based on this evidence, that in PKU some amino acids are partially excluded from entering the brain, proposals are made for a modified dietary treatment of this disease. In this diet the phenylalainine is not so greatly reduced as in the standard diet for PKU, whilst supplements of other amino acids are added. The rationale for this new diet is that the partial exclusion from the brain of various amino acids (methionine, tryptophan, histidine, tryosine, isoleucine, leucine and valine) by the raised level of phenylalanine in the blood, acting as a competitive inhibitor, can be largely prevented by increasing the blood levels of these excluded amino acids. Raising slightly their blood levels overcomes the excluding effect of moderately raised levels of phenylalanine in the blood. The advantages of the new diet are that not only is it more palatable than a diet very low in phenylalanine, so that it is more likely to continue to prove acceptable to older children and adolescents, as well as to PKU women who expect to become pregnant, but also that its margin of safety is greater if the patient does take unsuitable food.
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PMID:A new approach to the treatment of phenylketonuria. 719 42

This report documents the outcome of two pregnancies is a woman with phenylketonuria (PKU) who was treated with a low phenylalanine diet before conception and during pregnancy. Her first pregnancy resulted in an abortion at 17 wk. During the second pregnancy the patient was unable to maintain the right diet consistently, and her blood phenylalanine levels in the first and second trimester were elevated. This pregnancy ended in the birth of a growth retarded microcephalic infant after an amenorrhea of 42 wk. The infant has maintained a normal growth velocity below the tenth percentile, and has not shown signs of mental retardation.
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PMID:Maternal phenylketonuria: the outcome of pregnancy. 733 7

Since many women with phenylketonuria (PKU) will have children of their own, we were interested in ascertaining the effect of maternal PKU and hyperphenylalaninemia on the offspring of such women. We reviewed the literature on this subject and obtained additional unpublished data through an international survey. Data were collected on 524 pregnancies in 155 women; in 34 pregnancies a low-phenylalanine diet was begun after or shortly before pregnancy was established. Among untreated pregnancies, the frequencies of mental retardation, microcephaly, and congenital heart disease were greatly increased over those in the normal population, and these increases correlated with the mother's blood levels of phenylalanine. Ninety-five per cent of mothers with blood phenylalanine concentrations of 20 mg per deciliter or higher had at least one mentally retarded child. Bias introduced by case-finding methods cannot explain these results. It is not clear from our review whether dietary treatment begun after conception is helpful, but treatment begun before conception should be evaluated.
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PMID:Maternal phenylketonuria and hyperphenylalaninemia. An international survey of the outcome of untreated and treated pregnancies. 742 47

Four persons who exhibited prominent autistic features throughout life died when 4, 14, 27, and 33 years old. All were mentally retarded. One had documented phenylketonuria, but the cause of mental retardation and autistic behavior was undefined in three. At the time of autopsy, brain weights were within 2 SDs of the norm for age. Complete neuropathologic examination, including analysis of cortical neurons impregnated with the rapid Golgi method, failed to provide clues as to cause or the pathoanatomic substrate of autistic behavior in these cases.
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PMID:Autism and mental retardation: neuropathologic studies performed in four retarded persons with autistic behavior. 744 62

To determine the importance of an abnormal EEG in phenylketonuria (PKU), we reviewed 137 EEGs from 48 patients with PKU. Patients were divided into three groups: group 1 (n = 14) had only normal EEGs, group 2 (n = 20) had only abnormal EEGs, and group 3 (n = 14) initially had normal EEGs that later became abnormal. The most common EEG abnormality was focal paroxysmal discharge. Patients in group 2 started treatment at a later age an had a greater frequency of seizures and mental retardation. Phenylalanine levels greater than 20 mg/dL were more often associated with abnormal EEGs. Older patients were more likely to have abnormal EEGs; 78% of the 41 patients who had EEGs at age 6 or older had abnormal records, whereas only 15% of the 26 patients who had EEGs before the age of 6 had abnormal records. Conventionally treated patients with classic PKU and normal EEGs in infancy may have abnormal EEGs when retested later even though they remain on a restricted diet. Although not usually associated with clinical deterioration, abnormal EEGs may unveil the presence of CNS dysfunction even when a child is in satisfactory clinical condition.
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PMID:EEG in phenylketonuria. Attempt to establish clinical importance of EEG changes. 746 35


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