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Biomedical subjects

H L Levy

Publications and source records attributed to H L Levy.

At least 145 records · Page 8Linked to original sources
PubMed1984

Parental response to repeat testing of infants with 'false-positive' results in a newborn screening program.

Forty-five percent of the parents of 60 infants being retested in a newborn screening program for metabolic disorders understood that their infant was undergoing retesting because the first test result was abnormal. Fifty-five percent had incorrect or incomplete information, believing that retesting was routine, or that mistakes had been made in the original testing procedure, or they report being told nothing specific about the testing. Parents who were aware that the initial test was abnormal were no more anxious or depressed while waiting for the repeat test results than other parents. At a second interview after learning the normal results of the repeat test, both those parents informed of the initial abnormal result as well as those not informed were less anxious and depressed. However, 36% of the parents of these normal infants reported concern about the health of their infant because of the repeat testing. This concern was not related to a parent's knowledge that the initial test result was abnormal, but was greater in parents reporting that they had not received sufficient information about the screening/testing process and its significance for the health of their infant.

Adult↗
PubMed1983

Effects of untreated maternal phenylketonuria and hyperphenylalaninemia on the fetus.

We studied the effects of maternal phenylketonuria and hyperphenylalaninemia on 53 offspring from untreated pregnancies in 22 mothers who were identified by routine screening of umbilical-cord blood. The IQ of the offspring was significantly correlated with both maternal IQ (r = 0.83, P less than 0.001) and maternal blood phenylalanine level (r = 0.82, P less than 0.001), but with one exception, mental retardation in offspring was present only when the maternal blood phenylalanine level exceeded 1100 mumol per liter (18 mg per deciliter). Microcephaly in offspring was consistently present only when the maternal blood phenylalanine level exceeded 1200 mumol per liter (20 mg per deciliter). Congenital heart disease and other congenital anomalies were rare among offspring. The data suggest that severe atypical or classic phenylketonuria (blood phenylalanine level, greater than 1100 mumol per liter) in the mother has a substantial cognitive effect on her offspring but that the effect of mild hyperphenylalaninemia may have been overstated in the past.

Abortion, Spontaneous↗
PubMed1983

Evidence for liver disease preceding amino acid abnormalities in hereditary tyrosinemia.

In hereditary tyrosinemia, an autosomal recessive disorder of infants, it has been postulated that hepatic toxicity arising from defective degradation of tyrosine accounts for the severe liver disease that is a feature of this condition. We measured the concentration of alpha-fetoprotein, a marker for liver disease, and of amino acid in cord blood from three infants with hereditary tyrosinemia and found that the concentration of alpha-fetoprotein was greatly increased at birth, whereas the level of tyrosine was normal or not specifically elevated, and that hypertyrosinemia developed only postnatally. These results indicate that liver disease is prenatal in hereditary tyrosinemia and that therapy aimed at reduction of the elevated tyrosine level is unlikely to be of fundamental value.

Amino Acid Metabolism, Inborn Errors↗
PubMed1983

Histidinaemia. Part I: Reconciling retrospective and prospective findings.

We reach the conclusion that histidinaemia in the typical form (autosomal recessive impairment of L-histidine ammonia lyase activity (EC4.3.1.3)) is not a 'disease' in man. Retrospective and prospective studies (Rosenmann et al., 1983; Coulombe et al., 1983) together indicate that the prevalence of disadaptive phenotypes (e.g. impaired intellectual or speech development, seizures, behavioural or learning disorder) in the histidinaemia population, is not higher than the frequency of these functional disorders in the non-histidinaemia population. However, one cannot exclude the possibility that histidinaemia is a risk factor for development of an unfavourable CNS phenotype, in particular individuals under specific circumstances (e.g. abnormal perinatal events). From this viewpoint, we propose that newborn screening for early diagnosis and treatment of histidinaemia does not meet the criteria for a public health service. Screening for continuing research on histidinaemia remains justifiable, for example, to discern whether there are atypical forms of the biochemical and enzymatic phenotypes.

Amino Acid Metabolism, Inborn Errors↗
PubMed1983

Histidinaemia. Part II: Impact; a retrospective study.

Forty-two articles published between 1961 and 1977 describing 43 probands and 26 siblings with histidinaemia were used for the retrospective study. Our objective was to describe the apparent impact of the mutation on development and health in human histidinaemia. The findings were similar to those of an earlier survey (Popkin et al., 1974). Most probands (79%) had a disadaptive CNS phenotype (mental retardation, impaired speech, seizures, aberrant behaviour, and/or learning disorder); half the histidinaemic siblings had a similar phenotype. The modal IQ score was 70; age at recognition of symptoms (CNS phenotype) varied from 1 month to 16 y (modal age 2 1/2 y). There was no correlation between blood histidine (reported values) and occurrence of severity of CNS phenotype. Thirty per cent of histidinaemia subjects, for whom the perinatal history was described, had an abnormal experience. Reported cases with the CNS phenotype apparently represent a very small fraction (about 1%) of all subjects with histidinaemia; this implies that the histidinaemia phenotype is not disadaptive in man.

Adolescent↗
PubMed1983

Histidinaemia. Part III: Impact; a prospective study.

We describe a prospective study of histidinaemia. Probands and siblings (n = 21) with typical histidinaemia in 16 families were ascertained by newborn screening; diagnosis was confirmed by appropriate investigations in each subject; none had been treated by low histidine diet. The median age of subjects with histidinaemia was 9.5 y (mean 10.0, SD 3.5, range 6-18). Age-matched sib-pairs and their mothers were studied. IQ scores (Full Scale, Verbal and Performance Scores), Visual-Motor Integration Performance (Bender Gestalt and Koppitz scores), Wide Range Achievement Test (Reading and Mathematics), school performance, and psychological history were evaluated, as well as the medical history (pregnancy, delivery, neonatal, post-natal development). Findings were correlated with biochemical phenotype. CNS development in histidinaemic subjects (mean and distribution of scores) was normal; outlier values did not correlate with degree of histidinaemia. We can conclude that histidinaemia detected by newborn screening is a non-disadaptive phenotype.

Adolescent↗
PubMed1982

Maternal phenylketonuria--results of dietary therapy.

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.

Adult↗
PubMed1982

Comparison of treated and untreated pregnancies in a mother with phenylketonuria.

We have studied a family in which the mother has PKU and has had six pregnancies, three untreated and three treated with a low-phenylalanine diet begun during the first or second trimester. The three nonphenylketonuric offspring from two of the untreated pregnancies are mentally retarded and microcephalic. The two nonphenylketonuric offspring from two of the treated pregnancies are also microcephalic and have low or borderline low intelligence. One untreated pregnancy resulted in spontaneous abortion. One treated pregnancy resulted in stillbirth at seven months. It is not certain that dietary treatment of maternal PKU during pregnancy, when begun after conception, is sufficient to protect the fetus. This therapy may have to be ongoing at the time of conception for optimal fetal protection.

Abortion, Spontaneous↗
PubMed1982

A new method of screening for inherited disorders of galactose metabolism.

A method has been developed for detecting elevated levels of galactose and galactose-1-phosphate in routine blood samples of newborns and has been successfully applied as a screening procedure for galactosemia in several laboratories. The procedure utilizes a strain of Escherichia coli that becomes resistant to bacteriophage C21 in the presence of galactose. The presence of galactose or galactose-1-phosphate is detected as a zone of bacterial growth around blood spots placed on a dish in which the bacteria are otherwise killed by phage. The diameter of the growth zone is proportional to the concentration of total blood galactose. The procedure has the potential of detecting all metabolic abnormalities that can lead to the accumulation of galactose or galactose-1-phosphate. Over a million newborn infants have now been tested by this procedure in three countries. In the New England Regional Screening Program, 12 galactosemic children were detected in 825,403 live births. One additional case, a sibling of a previously diagnosed galactosemic, was not allowed any milk feeding and was detected by an enzymatic test of cord blood. The combined frequency was 1:63,000. No problems of interference by antibiotics were apparent. Use of the test in Switzerland and in Japan also allowed the discovery of infants with UDP galactose 4-epimerase deficiency. Our experience suggests that the test provides an efficient and reliable means of detecting congenital defects of galactose metabolism with a very low frequency of errors. It can also be used to monitor blood galactose levels in the management of galactosemic children.

Bacteriophages↗