Predictors of Intelligence Quotient and Intelligence Quotient Change in Persons Treated for Phenylketonuria Early in Life

PEDIATRICS ◽  
1987 ◽  
Vol 79 (3) ◽  
pp. 351-355
Author(s):  
Susan E. Waisbren ◽  
Barbara E. Mahon ◽  
Richard R. Schnell ◽  
Harvey L. Levy
Keyword(s):  
Intelligence Quotient ◽  
Dietary Control ◽  
Regression Analyses ◽  
Phenylalanine Level ◽  
Blood Phenylalanine

Ninety-one individuals with phenylketonuria who were treated early in life were followed for as many as 22 years. Regression analyses were used to determine the best predictors of IQ and IQ change. Among treatment-related variables, good dietary control of the blood phenylalanine level stood out as the best predictor of IQ. Diet discontinuation and the natural (off diet) blood phenylalanine level best predicted IQ loss, suggesting that diet continuation may be important for children with natural blood phenylalanine levels greater than 18 mg/dL.

Differential Diagnosis of Variant Forms of Hyperphenylalaninemia

PEDIATRICS ◽  
1980 ◽  
Vol 65 (4) ◽  
pp. 840-842
Author(s):  
Seymour Kaufman
Keyword(s):  
Differential Diagnosis ◽  
Phenylalanine Hydroxylase ◽  
Dietary Control ◽  
Elevated Blood ◽  
Dihydropteridine Reductase ◽  
Blood Phenylalanine ◽  
Neurologic Deterioration

In 1975, a form of hyperphenylalaninemia was described in which neurologic deterioration occurs despite dietary control of the elevated blood phenylalanine levels.1 Subsequently, it was demonstrated that this condition can be caused by defects in the phenylalanine hydroxylase system other than in phenylalanine hydroxylase itself, ie, by a tissue deficiency of dihydropteridine reductase (DHPR)2,3 or of biopterin.4 Since then, research in the field of these newer, unresponsive variants of phenylketonuria (PKU) has moved ahead swiftly. The treatment for these forms of hyperphenyl-alaninemia, which have been estimated to account for about 10% of the total, is different from that used for classic PKU.

Detection of Phenylketonuria in the Very Early Newborn Blood Specimen

PEDIATRICS ◽  
1991 ◽  
Vol 87 (2) ◽  
pp. 240-244
Author(s):  
Lauren Barnico Doherty ◽  
Frances J. Rohr ◽  
Harvey L. Levy
Keyword(s):  
At Risk ◽  
Newborn Screening ◽  
Hospital Discharge ◽  
Phenylalanine Level ◽  
Blood Specimen ◽  
Screening Programs ◽  
Early Hospital Discharge ◽  
Blood Phenylalanine ◽  
Breast Fed

Early hospital discharge of newborns is leading to collection of the newborn screening blood specimen during the first day of life in increasing numbers of newborns. There is concern that neonates with phenylketonuria who are tested this early may be missed. To examine this question, the authors screened specimens collected during the first 24 hours of life from 23 neonates at risk for hyperphenylalaninemia. The blood phenylalanine level in each of the 6 neonates with phenylketonuria and a seventh with mild hyperphenylalaninemia was greater than 2 mg/dL as early as 4 hours of age and 6 mg/dL or greater by 24 hours of age. A newborn screening phenylalanine cutoff level of 2 mg/dL would have identified all of these neonates within the first 24 hours of life, but a cutoff level of 4 mg/dL would have missed 2 of the 6 with phenylketonuria before 24 hours of life. Newborn screening programs should adopt a blood phenylalanine level of 2 mg/dL as the cutoff for suspicion of phenylketonuria and request for a second specimen. Breast-fed affected neonates had higher early blood phenylalanine elevations than formula-fed neonates, perhaps reflecting the higher protein (phenylalanine) content of colostrum.

Phenylketonuria: Implications of Initial Serum Phenylalanine Levels on Cognitive Development

1988 ◽  
Vol 63 (1) ◽  
pp. 135-142 ◽  
Author(s):  
A. Barclay ◽  
O. Walton
Keyword(s):  
Cognitive Development ◽  
Age At Onset ◽  
Blood Levels ◽  
Dietary Control ◽  
Biochemical Control ◽  
Phenylalanine Level ◽  
Initiation Of Therapy ◽  
Serum Phenylalanine

This study investigated influences of diagnostic phenylalanines, age at initiation of diet, and dietary control, separately and in combination, on cognitive development for 29 phenylketonuric children (17 boys and 12 girls) who ranged in age from 1 to 1,184 days. Initial serum phenylalanine concentrations and age at initiation of therapy were significantly related to cognitive development, whereas neither dietary and biochemical control relative to blood levels of phenylalanine or for these variables in combination exerted a statistically significant effect on measures of functioning. The interaction between initial serum phenylalanine level and age at onset of diet did reach nearly significant proportions, suggesting that the relation between diagnostic phenylalanines and subsequent cognitive development in the phenylketonuric population warrants further study. Despite an approximately 13-point decrease in IQs between initial (1 yr.) and most recent measurements (3 yr.), all 29 children were functioning in the normal or near-normal intellectual range at the most recent testing.

Event-related potential correlates of selective processing in early- and continuously-treated children with phenylketonuria: Effects of concurrent phenylalanine level and dietary control☆

2010 ◽  
Vol 99 ◽  
pp. S10-S17 ◽  
Author(s):  
Leo M.J. de Sonneville ◽  
Stephan C.J. Huijbregts ◽  
Francjan J. van Spronsen ◽  
Paul H. Verkerk ◽  
Joseph A. Sergeant ◽  
...  
Keyword(s):  
Event Related Potential ◽  
Dietary Control ◽  
Phenylalanine Level ◽  
Selective Processing

Language and Literacy Predictors of Dialect Density Among School-Age African American Children From Two Geographic Regions

2020 ◽  
Vol 51 (3) ◽  
pp. 807-820
Author(s):  
Lena G. Caesar ◽  
Marie Kerins
Keyword(s):  
African American ◽  
Multiple Regression ◽  
Oral Language ◽  
East Coast ◽  
Geographic Region ◽  
Literacy Skills ◽  
School Age ◽  
Regression Analyses ◽  
Geographic Regions ◽  
American Children

Purpose The purpose of this study was to investigate the relationship between oral language, literacy skills, age, and dialect density (DD) of African American children residing in two different geographical regions of the United States (East Coast and Midwest). Method Data were obtained from 64 African American school-age children between the ages of 7 and 12 years from two geographic regions. Children were assessed using a combination of standardized tests and narrative samples elicited from wordless picture books. Bivariate correlation and multiple regression analyses were used to determine relationships to and relative contributions of oral language, literacy, age, and geographic region to DD. Results Results of correlation analyses demonstrated a negative relationship between DD measures and children's literacy skills. Age-related findings between geographic regions indicated that the younger sample from the Midwest outscored the East Coast sample in reading comprehension and sentence complexity. Multiple regression analyses identified five variables (i.e., geographic region, age, mean length of utterance in morphemes, reading fluency, and phonological awareness) that accounted for 31% of the variance of children's DD—with geographic region emerging as the strongest predictor. Conclusions As in previous studies, the current study found an inverse relationship between DD and several literacy measures. Importantly, geographic region emerged as a strong predictor of DD. This finding highlights the need for a further study that goes beyond the mere description of relationships to comparing geographic regions and specifically focusing on racial composition, poverty, and school success measures through direct data collection.

Exploring the Potential Impact of Sentence-Level Comprehension and Sentence-Level Fluency on Deaf Students' Passage Comprehension

2020 ◽  
Vol 63 (7) ◽  
pp. 2281-2292
Author(s):  
Ying Zhao ◽  
Xinchun Wu ◽  
Hongjun Chen ◽  
Peng Sun ◽  
Ruibo Xie ◽  
...  
Keyword(s):  
Independent Predictor ◽  
Vocabulary Knowledge ◽  
Group Differences ◽  
Regression Analyses ◽  
Deaf Students ◽  
Mediating Role ◽  
Sentence Level ◽  
Mediating Mechanisms ◽  
Potential Impact ◽  
The Relationship

Purpose This exploratory study aimed to investigate the potential impact of sentence-level comprehension and sentence-level fluency on passage comprehension of deaf students in elementary school. Method A total of 159 deaf students, 65 students ( M age = 13.46 years) in Grades 3 and 4 and 94 students ( M age = 14.95 years) in Grades 5 and 6, were assessed for nonverbal intelligence, vocabulary knowledge, sentence-level comprehension, sentence-level fluency, and passage comprehension. Group differences were examined using t tests, whereas the predictive and mediating mechanisms were examined using regression modeling. Results The regression analyses showed that the effect of sentence-level comprehension on passage comprehension was not significant, whereas sentence-level fluency was an independent predictor in Grades 3–4. Sentence-level comprehension and fluency contributed significant variance to passage comprehension in Grades 5–6. Sentence-level fluency fully mediated the influence of sentence-level comprehension on passage comprehension in Grades 3–4, playing a partial mediating role in Grades 5–6. Conclusions The relative contributions of sentence-level comprehension and fluency to deaf students' passage comprehension varied, and sentence-level fluency mediated the relationship between sentence-level comprehension and passage comprehension.

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