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Biomedical subjects

C Netley

Publications and source records attributed to C Netley.

At least 19 recordsLinked to original sources
PubMed1996

The psychoeducational profile of boys with Klinefelter syndrome.

Klinefelter syndrome (KS) affects about 1 in 900 males due to an extra X chromosome. Although there are no obvious physical features associated with childhood KS, many boys demonstrate a cognitive deficit in verbal processing. The first section of this article integrates the extant literature on intelligence and achievement outcomes in boys with KS. The second section presents our findings from a 20-year study involving one of the largest unselected cohorts of boys with KS. We followed 36 boys with KS and 33 sibling controls from 6 until 20 years of age. Boys with KS are shown to demonstrate a verbal cognitive deficit and significant underachievement in reading and spelling, as well as in arithmetic. These problems, which are evident from early school years, increase with age such that by late adolescence, boys with KS are four to five grade levels behind. In addition, we also found that they were most likely to have a generalized type of learning disability, with very few boys indicating a pure reading or pure arithmetic problem. They also showed deficits in written language skills and acquisition of knowledge-based subject material were also problematic. Despite significant underachievement and frequent grade failure, many boys with KS had completed high school, and a few were also pursuing postsecondary educations. The discussion section examines how their language-based disability affects comprehension and learning, leading to underachievement.

Achievement↗
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

Event-related potentials (ERPs) and intelligence in neonatally identified 47,XXY males.

The event-related potentials (ERPs) of 18 extra X males (mean age 18.1 years) were recorded during the course of phonemic and orthographic discrimination tasks. The N2 and P3 latencies and amplitudes of subjects were examined in relation to their verbal and nonverbal intelligence test scores based on assessments at three ages: prior to puberty, during puberty and at sexual maturity. The results indicated that verbal abilities at most test occasions were significantly related to P3 latencies. Nonverbal abilities were largely uncorrelated with ERPs. The findings suggest that the verbal deficits of extra X males are the result of unlateralized individual differences in neural cognitive processing.

Adolescent↗
PubMed1992

Time of pubertal onset, testosterone levels and intelligence in 47,XXY males.

This study examined the relations between verbal and performance IQs, time of pubertal onset and testosterone levels from 13 to 16 years of age in a sample of 30 males with a supernumerary X chromosome. The findings indicated that verbal IQs measured prior to puberty, during puberty and at mid-adolescence were strongly related to relatively early pubertal onset and testosterone levels. Performance IQs had little or no relationship with the same variables. The results are discussed in terms of several different psychobiological models.

Adolescent↗
PubMed1992

[The effects of perinatal infection with the HIV virus on the development of adaptive behavior].

This study examined the development of adaptive functioning in nine HIV-positive and nine HIV-negative children ranging in age from 3 months to 6 years, 11 months. Both groups showed normal development of adaptive behaviour prior to two years of age; after this time the HIV-positive group was impaired in all areas of functioning. The results are discussed in terms of the program needs of the HIV-infected children and their families.

Adaptation, Psychological↗
PubMed1991

Personality in 47, XXY males during adolescence.

The responses to the High School Personality Questionnaire and the Million Adolescent Personality Inventory of a series of neonatally identified 47, XXY adolescent males and age-matched controls were compared. The extra X males' results indicated that they were more assertive, impulsive and prone to conflict than controls. Individual differences in these characteristics among the extra X cases had little relationship to quality of parenting but were related to indices of pubertal development.

Adolescent↗
PubMed1988

Relationships between hemispheric lateralization, sex hormones, quality of parenting and adjustment in 47,XXY males prior to puberty.

This paper reports findings of a study examining the degree to which intelligence, levels of sex-steroids and gonadotropins, quality of parenting and laboratory-based measures of left and right hemispheric specialization are associated with individual differences in psychosocial functioning in pre-pubertal 47,XXY males. The results indicate that activity level and freedom from tendencies towards withdrawal in these subjects are best predicted by the normality of their left hemispheric functioning.

Child↗
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

Predicting intellectual functioning in 47,XXY boys from characteristics of sibs.

Observations on the intellectual and educational functioning of neonatally identified 47,XXY boys and their sibs are presented. Equations for predicting the intellectual abilities of extra X boys on the basis of those of their sibs are provided. These may be useful to professionals engaged in counselling parents or possible parents of 47,XXY males.

Child↗
PubMed1984

Phenylketonuria and its variants: observations on intellectual functioning.

The age at diagnosis, dietary treatment and intelligence quotient (IQ) of 119 patients with phenylketonuria (PKU) and its variants who were under long-term observation were studied. In 27 of the 79 patients with classic PKU the diagnosis had been made and treatment begun late (after 2 months of age). The mean IQ of these 27 patients was 57.6 when they were in their early 20s (although 2 had normal IQs). In contrast, among the 52 patients with classic PKU who were not treated late the mean IQ was 93.6 for the 27 who were still receiving dietary therapy. The mean IQs were 99.3 and 92.7 at ages 5 (when the diet was discontinued) and 15 years respectively for the 12 who had been treated "adequately". It was 76.0 for the 13 who were "over-treated" (malnourished) in the first 6 months of life. Among the patients with atypical PKU, who were treated early, the mean IQs were 110.0 for the 7 who were still receiving dietary therapy and 102.7 for the 12 who were not. The 21 patients with persistent benign hyperphenylalaninemia, who were not treated, had a mean IQ of 104.2. The most important factor in the ultimate IQ of patients with classic PKU is very early diagnosis (by 2 weeks of age) along with immediate initiation of dietary therapy.

Adolescent↗
PubMed1984

Effects of different methods of treatment of primary enuresis on psychologic functioning in children.

Sixty-two children with primary nocturnal enuresis were assigned randomly to one of two groups. Group 1 was treated with imipramine hydrochloride, and group 2 received a course of treatment with the Mozes Detector. Seventeen children from group 1 and 18 from group 2 were tested with the age-appropriate form of the Cattell personality questionnaire on three occasions: at the time of entry into the study, 2 months later and at follow-up, an average of 16 months later. The patients in group 2, who were older, had a higher rate of cure than did the patients in group 1. They also had significantly higher levels of extroversion and significantly lower levels of neuroticism at follow-up than did those in group 1. These findings indicate that better results are seen with the Mozes Detector than with imipramine in older children with primary nocturnal enuresis.

Child↗
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

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↗