The Resource Mothers Program for Maternal Phenylketonuria.
(1/13)
OBJECTIVES: The purpose of this study was to measure the effectiveness of resource mothers in reducing adverse consequences of maternal phenylketonuria. METHODS: Nineteen pregnancies in the resource mothers group were compared with 64 pregnancies in phenylketonuric women without resource mothers. Weeks to metabolic control and offspring outcome were measured. RESULTS: Mean number of weeks to metabolic control was 8.5 (SE = 2.2) in the resource mothers group, as compared with 16.1 (SE = 1.7) in the comparison group. Infants of women in the resource mothers group had larger birth head circumferences and higher developmental quotients. CONCLUSIONS: The resource mothers program described here improves metabolic control in pregnant women with phenylketonuria. (+info)
Effect of phenylalanine and its metabolites on the proliferation and viability of neuronal and astroglial cells: possible relevance in maternal phenylketonuria.
(2/13)
Phenylketonuria is a genetic defect that, without strict dietary control, results in the accumulation of phenylalanine (Phe) in body fluids. If a low-Phe diet is not maintained during pregnancy, the offspring of phenylketonuric women are born with mental retardation and microcephaly. Primary cultures of rat cerebellar granule cells, rat cortical astrocytes, human fetal astrocytes, and human neuroblastoma (SY5Y) cells and human astrocytoma (1321N1) cells were used to test the hypothesis that the microencephaly may be a result of neuronal cell death and reduced astrocyte proliferation. Exposure to Phe or to six Phe metabolites [phenylacetic acid (PAA), phenyllactic acid, hydroxyphenylacetic acid, phenylpyruvic acid, phenylethylamine (PEA), and mandelic acid] did not result in astroglial or neuronal cell cytotoxicity. Treatment of 1321N1 cells, human fetal astrocytes, or rat astrocytes with 5 mM Phe for 24 h decreased DNA synthesis 19 +/- 4, 30 +/- 4, and 60 +/- 6%, respectively. This effect was concentration dependent, and flow cytometry revealed that Phe treatment resulted in the accumulation of cells in the G(0)/G(1) phase of the cell cycle. In addition, in 1321N1 cells, exposure to 5 mM PAA, and in rat astrocytes, exposure to 0.5 mM PEA inhibited cell proliferation 42 +/- 4 and 55 +/- 4%, respectively. These metabolites also resulted in the accumulation of cells in the G(0)/G(1) phase of the cell cycle. In human fetal astrocytes, 0.5 mM PEA and 0.5 mM PAA resulted in a 41 +/- 12 and 52 +/- 11% reduction proliferation, respectively. (+info)
Intake of major nutrients by women in the Maternal Phenylketonuria (MPKU) Study and effects on plasma phenylalanine concentrations.
(3/13)
BACKGROUND: Women with untreated phenylketonuria (PKU) often have poor reproductive outcomes. OBJECTIVE: We assessed the effects of intakes of major nutrients on plasma phenylalanine concentrations and we measured phenylalanine hydroxylase activity and phenylalanine intakes in pregnant women with PKU. DESIGN: Dietary intakes and plasma phenylalanine concentrations were compared in 4 subject groups defined on the basis of plasma phenylalanine concentrations: group 1 (n = 23), <360 micromol/L by 10 wk gestation and 120-360 micromol/L throughout the remainder of pregnancy; group 2 (n = 46), <600 micromol/L but not <360 micromol/L by 10 wk gestation and 120-600 micromol/L throughout the remainder of pregnancy; group 3 (n = 24), <600 micromol/L by 10 wk gestation but >600 micromol/L at least once thereafter; group 4 (n = 147), never <600 micromol/L. RESULTS: Except in the first trimester, mean intakes of phenylalanine, energy, and fat tended to be greater in group 1 than in the other groups. The mean protein intake of group 1 tended to be greater than that of the other groups. Intakes of protein (P < 0.0001), fat (P < 0.0001), and energy (P < 0.007) were negatively correlated with maternal plasma phenylalanine concentrations. It appeared that genotype did not affect phenylalanine tolerance. CONCLUSIONS: Maternal genotype appeared to have little influence on phenylalanine requirements during the first trimester. Early decline and maintenance of maternal plasma phenylalanine concentrations at <360 micromol/L and mean protein intake greater than the recommended dietary allowance (RDA) with mean energy intake near the RDA resulted in the best reproductive outcomes. Inadequate intakes of protein, fat, and energy may result in elevated plasma phenylalanine concentrations and may contribute to poor reproductive outcomes. (+info)
Barriers to dietary control among pregnant women with phenylketonuria--United States, 1998-2000.
(4/13)
Newborns in the United States are screened for phenylketonuria (PKU), a metabolic disorder that when left untreated is characterized by elevated blood phenylalanine (phe) levels and severe mental retardation (MR). An estimated 3,000-4,000 U.S.-born women of reproductive age with PKU have not gotten severe MR because as newborns their diets were severely restricted in the intake of protein-containing foods and were supplemented with medical foods (e.g., amino acid-modified formula and modified low-protein foods). When women with PKU do not adhere to their diet before and during pregnancy, infants born to them have a 93% risk for MR and a 72% risk for microcephaly. These risks result from the toxic effects of high maternal blood phe levels during pregnancy, not because the infant has PKU. The restricted diet, which should be maintained for life, often is discontinued during adolescence. This report describes the pregnancies of three women with PKU and underscores the importance of overcoming the barriers to maintaining the recommended dietary control of blood phe levels before and during pregnancy. For maternal PKU-associated MR to be prevented, studies are needed to determine effective approaches to overcoming barriers to dietary control. (+info)
Maternal phenylketonuria: report from the United Kingdom Registry 1978-97.
(5/13)
BACKGROUND: The effects of maternal phenylalanine on the fetus include facial dysmorphism, microcephaly, intrauterine growth retardation, developmental delay, and congenital heart disease. AIMS: To evaluate the impact of phenylalanine restricted diet in pregnant women with phenylketonuria (PKU) on their offspring. METHODS: Data on virtually all pregnancies of women with PKU in the United Kingdom between 1978 and 1997 were reported to the United Kingdom PKU Registry. The effect of the use and timing in relation to pregnancy of a phenylalanine restricted diet on birth weight, birth head circumference, the presence or absence of congenital heart disease (CHD), 4 year developmental quotient, and 8 year intelligence quotient were examined. RESULTS: A total of 228 pregnancies resulted in live births (seven twin pregnancies were excluded). In 110 (50%), diet started before conception. For this group mean (SD) birth weight was 3160 (612) g, birth head circumference 33.6 (1.9) cm, 4 year DQ 108.9 (13.2), 8 year IQ 103.4 (15.6), and incidence of CHD was 2.4%. In comparison, for those born where treatment was started during pregnancy (n = 91), birth weight was 2818 (711) g, birth head circumference 32.7 (2.0) cm, 4 year DQ 96.8 (15.0), 8 year IQ 86.5 (13.0), and incidence of CHD was 17%. Month-by-month regression analyses suggested that metabolic control by 12-16 weeks gestation had most influence on outcome. CONCLUSIONS: Many features of the maternal PKU syndrome are preventable by starting a phenylalanine restricted diet. Women with PKU and their carers must be aware of the risks and should start the diet before conception, or as soon after as possible. (+info)
An exceptional Albanian family with seven children presenting with dysmorphic features and mental retardation: maternal phenylketonuria.
(6/13)
BACKGROUND: Phenylketonuria is an inborn error of amino acid metabolism which can cause severe damage to the patient or, in the case of maternal phenylketonuria, to the foetus. The maternal phenylketonuria syndrome is caused by high blood phenylalanine concentrations during pregnancy and presents with serious foetal anomalies, especially congenital heart disease, microcephaly and mental retardation. CASE PRESENTATION: We report on an affected Albanian woman and her seven children. The mother is affected by phenylketonuria and is a compound heterozygote for two pathogenetic mutations, L48S and P281L. The diagnosis was only made in the context of her children, all of whom have at least one severe organic malformation. The first child, 17 years old, has a double-chambered right ventricle, vertebral malformations and epilepsy. She is also mentally retarded, microcephalic, exhibits facial dysmorphies and small stature. The second child, a girl 15 years of age, has severe mental retardation with microcephaly, small stature and various dysmorphic features. The next sibling, a boy, died of tetralogy of Fallot at the age of three months. He also had multiple vertebral and rib malformations. The subsequent girl, now eleven years old, has mental retardation, microcephaly and epilepsy along with facial dysmorphy, partial deafness and short stature. The eight-year-old child is slightly mentally retarded and microcephalic. A five-year-old boy was a premature, dystrophic baby and exhibits mental retardation, dysmorphic facial features, brachydactyly and clinodactyly of the fifth finger on both hands. Following a miscarriage, our index case, the youngest child at two years of age, is microcephalic and mentally retarded and shows minor facial anomalies. All children exhibit features of phenylalanine embryopathy caused by maternal phenylketonuria because the mother had not been diagnosed earlier and, therefore, never received any diet. CONCLUSION: This is the largest family suffering from maternal phenylketonuria reported in the literature. Maternal phenylketonuria remains a challenge, especially in woman from countries without a neonatal screening program. Therefore, it is mandatory to be alert for the possibility of maternal phenylketonuria syndrome in case of a child with the clinical features described here to prevent foetal damage in subsequent siblings. (+info)
Pregnancy in phenylketonuria: dietary treatment aimed at normalising maternal plasma phenylalanine concentration.
(7/13)
The transport characteristics of the placenta, which favour higher phenylalanine concentrations in the fetus than in the mother, and regression data of head circumference at birth against phenylalanine concentration at conception in maternal phenylketonuria (PKU), suggest that treatment of maternal PKU should ideally aim to maintain plasma phenylalanine concentration within the normal range throughout pregnancy. A patient with classical PKU was treated from before conception by aiming to maintain plasma phenylalanine concentration within the range 50-150 mumol/l and tyrosine within the range 60-90 mumol/l. The diet was supplemented with phenylalanine-free amino acids (100-180 g/day) and tyrosine (0-5 g/day). Plasma amino acid concentrations were monitored weekly by amino acid analyser. Dietary phenylalanine intake ranged from 6 mg/kg/day at conception to 30 mg/kg/day at delivery. Normal weight gain and fetal growth were maintained throughout the pregnancy. A normal baby was born at term with a head circumference of 35.5 cm; at 1 year of age no abnormality is detectable. These results show that with careful monitoring and compliance it is possible, and may be advisable, to maintain plasma phenylalanine concentration within the normal range in the management of PKU pregnancy. (+info)
Factors influencing outcomes in the offspring of mothers with phenylketonuria during pregnancy: the importance of variation in maternal blood phenylalanine.
(8/13)
BACKGROUND: Developmental delay in the offspring of women with phenylketonuria (PKU) can be prevented by maintaining maternal blood phenylalanine (Phe) within a target range (100-250 micromol/L). OBJECTIVE: We aimed to analyze outcomes in the offspring of women with PKU during pregnancy and to identify prognostic factors. DESIGN: Occipitofrontal circumference at birth (OFC-B); developmental scores [developmental quotient (DQ) and intelligence quotient (IQ)]at 1, 4, 8, and 14 y; and the time of starting a Phe-restricted diet (before or after conception) were collected. The influence of maternal Phe concentrations during pregnancy on offspring outcomes also was assessed. RESULTS: The study included 105 children born to 67 mothers with PKU. Mean (+/-SD) OFC-B z scores did not differ between the preconception and postconception diet groups (0.42 +/- 1.24 and -0.96 +/- 1.19, respectively). DQ at 1 y and IQ at 8 y were higher in offspring from the preconception diet group than in offspring from the postconception diet group [DQ: 107 +/- 13.8 and 99.3 +/- 13.3, respectively (P = 0.014); IQ: 110.6 +/- 14.8 and 91.2 +/- 23.9, respectively (P = 0.005)]. Maternal Phe concentrations correlated negatively with DQ and IQ scores, and variations (SD) in all maternal blood Phe correlated negatively with 4-, 8-, and 14-y IQ scores (r = -0.385, -0.433, and -0.712; P = 0.002, 0.008, and 0.031, respectively), even when concentrations were consistently within the target range. CONCLUSIONS: The study suggests that women with PKU should start a Phe-restricted diet before conception. Maintenance of maternal blood Phe within the target range predicts good offspring outcomes, but variations even within that range should be avoided. (+info)