Search PubMed⌕ Search

Biomedical subjects

J Rovet

Publications and source records attributed to J Rovet.

At least 37 records · Page 2Linked to original sources
PubMed1995

Intelligence and achievement in children with extra X aneuploidy: a longitudinal perspective.

Forty-seven children (35 male, 12 female) identified as having a supernumerary X chromosome by neonatal screening were studied psychologically from childhood to late adolescence. This paper compares their findings relative to sibling controls on tests of intelligence and achievement collected over a 14-year period. Children with a supernumerary X chromosome were found to score consistently below controls on Verbal IQ and subtests comprising the Verbal Comprehension factor but they did not differ on Performance IQ, which was in the normal range. At all ages, they showed poorer reading and arithmetic achievement; relative risk for reading and arithmetic impairment was 2.6 and 2.6 in males and 1.1 and 1.7 in females. Males with an extra X chromosome were more likely to receive special education than females, who more often failed a grade. Academic achievement was not affected in aneuploid children with higher levels of intelligence. Overall, these results suggest milder impairment than previously reported, particularly among trisomy X females.

Achievement↗
PubMed1995

Savant characteristics in a child with developmental delay and deletion in the short arm of chromosome 20.

The development outcome of a four-year-old boy with a deletion of the short arm of chromosome 20 is described. Despite a number of early medical problems, including infantile hypoglycemic convulsions secondary to growth hormone deficiency and delayed motor and language development, he has been reading (self-taught) since 2.5 years and currently has computer proficiency, and exceptional memory for maps and spatial locations, an extremely rich and active fantasy life, good diction, and an extensive spoken vocabulary. Neuropsychological evaluation revealed low-average intelligence with normal language, memory and attention functions, and impaired visuomotor and graphomotor ability and motor skills. He showed extremely advanced decoding and reading comprehension skills while mathematics, spelling and general knowledge abilities were average.

Achievement↗
PubMed1994

Neurodevelopment of adopted children exposed in utero to cocaine.

OBJECTIVE: To assess the neurodevelopment of adopted children who had been exposed in utero to cocaine. DESIGN: A case-control observational study. PARTICIPANTS: Twenty-three children aged 14 months to 6.5 years exposed in utero to cocaine and their adoptive mothers, and 23 age-matched control children not exposed to cocaine and their mothers, matched with the adoptive mothers for IQ and socioeconomic status. SETTING: The Motherisk Programme at The Hospital for Sick Children, Toronto, a consultation service for chemical exposure during pregnancy. MAIN OUTCOME MEASURES: Height, weight and head circumference at birth and at follow-up, and achievement on standard tests of cognitive and language development. RESULTS: Compared with the control group, children exposed in utero to cocaine had an 8-fold increased risk for microcephaly (95% confidence interval 1.5 to 42.3); they also had a lower mean birth weight (p = 0.005) and a lower gestational age (p = 0.002). In follow-up the cocaine-exposed children caught up with the control subjects in weight and stature but not in head circumference (mean 31st percentile v. 63rd percentile) (p = 0.001). Although there were no significant differences between the two groups in global IQ, the cocaine-exposed children had significantly lower scores than the control subjects on the Reynell language test for both verbal comprehension (p = 0.003) and expressive language (p = 0.001). CONCLUSIONS: This is the first study to document that intrauterine exposure to cocaine is associated with measurable and clinically significant toxic neurologic effects, independent of postnatal home and environmental confounders. Because women who use cocaine during pregnancy almost invariably smoke cigarettes and often use alcohol, it is impossible to attribute the measured toxic effects to cocaine alone.

Adoption↗
PubMed1994

Neurodevelopment of children exposed in utero to phenytoin and carbamazepine monotherapy.

OBJECTIVE: To compare pregnancy outcome prospectively after phenytoin and carbamazepine monotherapy with outcome in matched mother-child pairs exposed to nonteratogens to evaluate the relative fetal safety of these drugs. DESIGN: A prospective, controlled, and blinded observational study. PATIENTS: Thirty-six mother-child pairs exposed to carbamazepine monotherapy and 34 pairs exposed to phenytoin monotherapy, all prospectively studied, were compared with mother-child pairs exposed to nonteratogens. The controls were matched for maternal age, time of consultation, obstetric history, and socioeconomic status. MAIN OUTCOME MEASURE: The primary end point of interest was the children's global IQ measured by either the Bayley or the McCarthy scale according to their ages. SETTING: A teratology consultation program and two neurology services in Toronto, Ontario. RESULTS: Children exposed to phenytoin in utero had a mean (+/- SD) global IQ 10 points lower (95% confidence interval, 4.9 to 15.8 points) than their matched controls (113.4 +/- 13.1 and 103.1 +/- 25.1; P = .038). The Reynell language development scores followed a similar trend, with children exposed to phenytoin scoring significantly lower than their controls. Phenytoin-exposed children had a global IQ of 84 or less significantly more often than the control group (P < .01). Children exposed in utero to carbamazepine did not differ from their controls on any of the neurobehavioral tests. CONCLUSIONS: Our study suggests a clinically important negative effect of phenytoin on neurobehavioral development, independent of maternal or environmental factors, causing a substantial number of children to achieve a lower score than expected on cognitive tests. No similar effects could be shown after gestational use of carbamazepine.

Carbamazepine↗
PubMed1994

Specific arithmetic calculation deficits in children with Turner syndrome.

Study 1 compared arithmetic processing skills on the WRAT-R in 45 girls with Turner syndrome (TS) and 92 age-matched female controls. Results revealed significant underachievement by subjects with TS, which reflected their poorer performance on problems requiring the retrieval of addition and multiplication facts and procedural knowledge for addition and division operations. TS subjects did not differ qualitatively from controls in type of procedural error committed. Study 2, which compared the performance of 10 subjects with TS and 31 controls on the Keymath Diagnostic Arithmetic Test, showed that the TS group had less adequate knowledge of arithmetic, subtraction, and multiplication procedures but did not differ from controls on Fact items. Error analyses revealed that TS subjects were more likely to confuse component steps or fail to separate intermediate steps or to complete problems. TS subjects relied to a greater degree on verbal than visual-spatial abilities in arithmetic processing while their visual-spatial abilities were associated with retrieval of simple multidigit addition facts and knowledge of subtraction, multiplication, and division procedures. Differences between the TS and control groups increased with age for Keymath, but not WRAT-R, procedures. Discrepant findings are related to the different task constraints (timed vs. untimed, single vs. alternate versions, size of item pool) and the use of different strategies (counting vs. fact retrieval). It is concluded that arithmetic difficulties in females with TS are due to less adequate procedural skills, combined with poorer fact retrieval in timed testing situations, rather than to inadequate visual-spatial abilities.

Adolescent↗
PubMed1994

Behavioral phenotype in children with Turner syndrome.

Compared Child Behavior Checklist results in 103 girls with Turner syndrome (TS) ages 7 to 13 years and 52 age-matched normal girls. Subjects with TS were part of a national study in Canada to evaluate growth hormone therapy in TS. Present data were obtained at baseline. Girls with TS scored below the comparison group in Total Social Competence (p < .0001), and above it in Total Behavior Problems (p < .05), Social (p < .0001), and Attention Problems (p < .001) scales. Item analysis revealed that subjects with TS were more immature, hyperactive, and nervous, and had poorer peer relations, greater difficulty at schooling, and more problems concentrating. In children with TS, height was correlated with social competence while karyotypes involving structural abnormalities of the X chromosome were associated with more behavior problems than a missing X or mosaicism.

Adolescent↗
PubMed1993

Psychological aspects of the Canadian randomized controlled trial of human growth hormone and low-dose ethinyl oestradiol in children with Turner syndrome. The Canadian Growth Hormone Advisory Group.

Preliminary results are presented after 2 years of the Canadian long-term multicentre study on the impact of hormone therapy on the final height, sexual development and psychological status of girls with Turner syndrome. Girls entering the study were randomized either to be treated with recombinant human growth hormone or to act as controls. Both groups received oestrogen replacement therapy in the same dose and format at the age of 13 years. However, for the purposes of the psychological study at this time, children receiving oestrogen were excluded from analysis. Girls treated with GH for a period of 2 years showed a significant increase in growth rate, which declined with continued treatment, while the growth rate in the control group remained constant throughout. There was a correlation between the higher growth rate and the girls' perceptions of themselves as more intelligent, more attractive, having more friends, greater popularity and experiencing less teasing than the untreated group. Growth rate was not correlated with family or school functioning.

Analysis of Variance↗
PubMed1987

Relations between a dermatoglyphic measure, hemispheric specialization, and intellectual abilities in 47,XXY males.

Verbal IQ is usually lower than performance IQ in neonatally identified 47,XXY males. A dermatoglyphic measure reflecting prenatal growth rates and indices of sex-related hormonal functioning are also frequently abnormal in 47,XXY males. This paper presents evidence indicating that a measure of prenatal growth rate predicts right hemispheric specialization for nonverbal processing in extra X males, whereas levels of testosterone, estradiol, luteinizing hormone, and follicle-stimulating hormones do not. Findings are also reported which indicate that the low verbal IQs of 47,XXY males are the result of abnormalities in right hemispheric functioning.

Child↗
PubMed1987

Intellectual outcome in children with fetal hypothyroidism.

Eighty children with congenital hypothyroidism detected by newborn screening were grouped for presence of fetal hypothyroidism using skeletal maturity at the time of diagnosis as the index. Forty-five children with bone age less than 36 weeks were assigned to the delayed group; 35 with bone age 37 weeks to term were assigned to the nondelayed group. Although most children with athyrosis were found in the delayed group, the groups did not differ in birth weight, hormone levels, or family background. Assessments of intellectual and behavioral characteristics at 1, 2, 3, 4, and 5 years of age revealed that, although children in the delayed group performed within the normal range, their scores were significantly lower than those of the nondelayed group from age 2 years on. Perceptual-motor, visuospatial, and language areas were most affected. There were no differences in behavior or temperamental characteristics.

Age Determination by Skeleton↗
PubMed1987

Behaviour problems in children with diabetes as a function of sex and age of onset of disease.

Twenty-seven children with early onset (less than or equal to 3 years) diabetes (EOD), 24 with late onset (greater than or equal to 4 years) diabetes (LOD) and 30 sibling controls were compared on measures of psychosocial adjustment. These included parent rating scales of behaviour problems and temperament; direct measures of self-esteem, body image and school achievement; and indices of diabetic control. Results indicated that LOD boys showed increased incidence of behaviour problems, 83% of whom could be assigned a diagnostic classification and more distortions of body image. The results were not related to any indices of diabetic control.

Adolescent↗
PubMed1984

Hemispheric lateralization in 47,XXY Klinefelter's syndrome boys.

Thirty-two boys with a 47,XXY karyotype were compared with chromosomally normal male controls in their performance on six tasks of hemispheric specialization. The results revealed that the 47,XXY subjects had smaller asymmetries on left hemisphere tasks and larger asymmetries on right hemisphere tasks than controls. Analyses of individual right and left side scores revealed that the atypical lateral asymmetries of the 47,XXYs were due to a shift toward greater right hemisphere involvement on four of the six measures. It was postulated that the slower fetal growth rates of the extra X chromosome group might contribute to their atypical hemispheric specialization and the failure of their left hemisphere to gain dominance over their right in language processing.

Auditory Perception↗
PubMed1983

Cognitive and neuropsychological test performance of persons with abnormalities of adolescent development: a test of Waber's hypothesis.

20 children with idiopathic precocious puberty, 27 adolescents with clinically delayed puberty, and an equivalent number of controls matched for age, sex, and IQ were given a battery of tests. These included measures of verbal and spatial abilities and a task assessing hemispheric lateralization using a dichotic listening procedure. Comparisons with matched controls revealed poorer verbal and spatial abilities for precocious males and poorer verbal, but better spatial, abilities for precocious females. Delayed developing males demonstrated superior verbal skills compared with controls, whereas delayed developing females did more poorly than controls in both verbal and spatial areas. On the dichotic task, the only group differing from controls was the delayed developing males, who demonstrated stronger lateral asymmetries. It was suggested that the present findings, which are not consistent with those of former investigations, may reflect methodological differences between studies and the disruptive influence of atypical pubertal onset on normal patterns of sex difference in cognitive functioning.

Adolescent↗
PubMed1983

The triple X chromosome syndrome in childhood: recent empirical findings.

This study addresses the issue of the relationship between intellectual ability and the X chromosome. It involves a sample of 11 girls ranging in age from 8 to 11 years who were identified at birth as having an extra X chromosome through a screening program for sex chromosome abnormalities. The purpose was to examine their performance on verbal, nonverbal, and memory tasks. The first study compared triple X girls with their normal siblings on standardized ability tasks. The results revealed markedly lower verbal skills in the extra X girls as well as a short-term memory deficit for sequentially ordered auditory information. The second study compared triple X subjects to age-matched normal girls on laboratory-based tasks of verbal and spatial information processing. The results revealed greater impairments with the verbal than the spatial task. The third study, which dealt with their recall abilities, involved comparing triple X girls with age- and ability-matched female controls on a wide variety of short-term memory tasks. The results showed that the triple X girls were markedly inferior in their performance on these tasks, indicating a rehearsal deficit, an inability to use list structures, and weaker language skills. The results are discussed in terms of the influence of various biological factors in mediating the deficits observed.

Achievement↗
PubMed1982

Atypical hemispheric lateralization in Turner syndrome subjects.

This study compares the dichotic listening task performance of 35 Turners syndrome (TS) and 35 normal females matched for age and verbal intelligence. The task consisted of 24 pairs of digit triads presented simultaneously to both ears. The results indicated that the TS subjects were less likely than controls to show a right ear advantage and more likely than controls to show a left ear advantage. The absence of an ear advantage was also found to be associated with the greatest nonverbal deficits, but only among TS subjects. The findings are discussed in terms of diminished hemispheric specializations in TS females.

Adolescent↗