Anthropometric adjustments are helpful in the interpretation of BMD and BMC Z-scores of pediatric patients with Prader-Willi syndrome.

Anthropometric adjustments of bone measurements are necessary in Prader-Willi syndrome patients to correctly assess the bone status of these patients. This enables physicians to get a more accurate diagnosis of normal versus abnormal bone, allow for early and effective intervention, and achieve better therapeutic results. INTRODUCTION: Bone mineral density (BMD) is decreased in patients with Prader-Willi syndrome (PWS). Because of largely abnormal body height and weight, traditional BMD Z-scores may not provide accurate information in this patient group. The goal of the study was to assess a cohort of individuals with PWS and characterize the development of low bone density based on two adjustment models applied to a dataset of BMD and bone mineral content (BMC) from dual-energy X-ray absorptiometry (DXA) measurements. METHODS: Fifty-four individuals, aged 5-20 years with genetically confirmed PWS, underwent DXA scans of spine and hip. Thirty-one of them also underwent total body scans. Standard Z-scores were calculated for BMD and BMC of spine and total hip based on race, sex, and age for all patients, as well as of whole body and whole-body less head for those patients with total-body scans. Additional Z-scores were generated based on anthropometric adjustments using weight, height, and percentage body fat and a second model using only weight and height in addition to race, sex, and age. RESULTS: As many PWS patients have abnormal anthropometrics, addition of explanatory variables weight, height, and fat resulted in different bone classifications for many patients. Thus, 25-70 % of overweight patients, previously diagnosed as normal, were subsequently diagnosed as below normal, and 40-60 % of patients with below-normal body height changed from below normal to normal depending on bone parameter. CONCLUSIONS: This is the first study to include anthropometric adjustments into the interpretation of BMD and BMC in children and adolescents with PWS. This enables physicians to get a more accurate diagnosis of normal versus abnormal BMD and BMC and allows for early and effective intervention.

Sexual dichotomy of gonadal function in Prader-Willi syndrome from early infancy through the fourth decade.

STUDY QUESTION: At what age does the type of hypogonadism, namely hypothalamic or primary gonadal defect, become established in men and women with Prader-Willi syndrome (PWS)? SUMMARY ANSWER: The type of hypogonadism becomes established only in late adolescence and early adulthood. WHAT IS KNOWN ALREADY: The etiology of hypogonadism in PWS is heterogeneous and the clinical expression is variable. Primary testicular failure is common in PWS men, while combinations of ovarian dysfunction and gonadotrophin deficiency are seen in women. STUDY DESIGN, SIZE, DURATION: This is a prospective study of a cohort of 106 PWS patients followed for a mean duration of 4.5 years. Serial blood samples were obtained and assayed for gonadotrophins, inhibin B, anti-Mullerian hormone (AMH), dehydroepiandrosterone sulfate (DHEAS), testosterone (males), and estradiol (females). Results were compared with normal reference values obtained from the literature. For the purpose of this study, we defined the following age groups: infants <1 year; children 1-10 years; adolescents 11-20 years and adults >20 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: Study participants were 49 males (aged 2 months to 36 years) and 57 females (aged 1 month to 37 years) with genetically confirmed diagnoses of PWS (deletions 60, uniparental disomy 54, imprinting center defect 2) followed in the Israel national multidisciplinary PWS clinic. MAIN RESULTS AND THE ROLE OF CHANCE: Serum LH levels were in the normal range (1.0-6.0 mIU/ml) for 7/10 adult men, and high in 3, while FSH (normal range 1.0-6.1 mIU/ml) was elevated (34.4 ± 11.5 mIU/ml) in 6 and normal (3.5 ± 1.6 mIU/ml) in 4 men. Testosterone was low (5.7 ± 3.4 nmol/l) compared with the normal range of 12.0-34.5 nmol/l in the reference population in all men >20 years. AMH showed a normal decrease with age, despite low testosterone levels. Inhibin B was normal (241 ± 105 pg/ml) in infant boys, but low or undetectable in most adult men. Hormonal profiles were more heterogeneous in women than in men. Estradiol was consistently detectable in only 7/13 adult women. Inhibin B was low or undetectable in all PWS females although occasional samples showed levels within the normal range of 15-95 pg/ml. Vaginal bleeding was reported to occur for the first time in eight women at a median age of 20 years (13-34 years), but only one had regular monthly menses. The type of hypogonadism (primary or secondary) in PWS can be determined only after age 20 years. LIMITATIONS, REASONS FOR CAUTION: The study cohort was heterogeneous, showing variability in BMI, cognitive disability and medical treatment. WIDER IMPLICATIONS OF THE FINDINGS: Demonstration of the natural history of reproductive hormone development in PWS suggests that androgen replacement may be indicated for most PWS boys in mid-adolescence. Recommendations for hormone replacement in PWS women need to be individually tailored, serial measurements of inhibin B should be performed, and contraception should be considered in those women who may have the potential for fertility.

Genome-wide association study of Tourette's syndrome.

Tourette's syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (P<5 × 10(-8)); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (P=1.85 × 10(-6)). A secondary analysis including an additional 211 cases and 285 controls from two closely related Latin American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (P=3.6 × 10(-7) for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder.

Accidental injuries are more common in children with attention deficit hyperactivity disorder compared with their non-affected siblings.

BACKGROUND: Accidental injuries are a leading cause of paediatric morbidity and mortality. We hypothesized that attention deficit hyperactivity disorder (ADHD), a common childhood disorder characterized by behaviours such as hyperactivity and impulsivity, is a risk factor for accidental injuries. Previous retrospective studies suggested that children with ADHD have an increased injury rate, but controlled prospective studies are lacking. METHODS: We conducted a prospective case-control study of 29 school-aged children with ADHD and their same-sex, similarly aged, non-ADHD-affected siblings. All diagnoses were made by a paediatric neurologist according to DSM-IV criteria and the children and their parents underwent a structured psychiatric interview and a battery of complementary assessments including: Child Behavior Checklist (CBCL), ADHD Rating scale and Developmental Coordination Disorder Questionnaire (DCDQ). The parents were contacted by telephone every 3 months during a 9-month follow-up period and all injuries requiring medical attention were recorded. Incidence of injuries was compared between the pairs of siblings. RESULTS: During the follow-up period, a total of 13 injuries in 13 children with ADHD were reported, compared with six injuries in six children from the control group (Z=-2.11, P < 0.05). ADHD severity and subtype, CBCL, DCDQ and IQ scores were not predictive of injury risk. CONCLUSIONS: School-aged children with ADHD are at higher risk of accidental injuries than their non-ADHD siblings, regardless of ADHD subtype, co-morbid psychiatric conditions, developmental co-ordination problems and environmental/familial conditions. Awareness and adequate education of parents and caregivers of children with ADHD concerning the increased injury risks are thus warranted.

Psychiatric disorders in a cohort of individuals with Prader-Willi syndrome.

BACKGROUND: Psychiatric manifestations in Prader-Willi Syndrome (PWS) are common and often are the most debilitating problem in these individuals. We present an epidemiological nation-wide survey of psychiatric diagnoses in the PWS population, based on full-range psychiatric interviews. METHODS: We studied the distribution of psychiatric diagnoses (as opposed to a symptom-based approach) in the Israel national cohort of adolescents and adults with PWS. There was a total of 53 (32 males) ages 12 years and older. All individuals and their caretakers were interviewed using standardized psychiatric questionnaires. Demographic and clinical variables, Clinical Global Impression (CGI) score, IQ, severity of hyperphagia and quality of life (QOL) were also assessed and correlations with NPD (number of psychiatric diagnoses) calculated. RESULTS: An overwhelming majority (89%) of the study participants had at least one psychiatric diagnosis. The most common were disruptive behavior disorders (DBD) (68%), obsessive compulsive disorder (OCD) (45%) and skin picking (35%). Individuals with DBD were at increased risk for OCD and skin picking. Psychotic disorders were found in 11%. NPD had a significant negative influence on QOL. There was no correlation between NPD and BMI, IQ, hyperphagia severity, hormonal profile or genetic subtypes. CONCLUSIONS: Psychiatric diagnoses are very frequent in PWS and strongly influence QOL. Furthermore, characterizing the profile of psychiatric comorbidity in PWS is crucial for planning effective interventions. Precise behavioral phenotyping in PWS in combination with a well-defined genetic etiology may aid biological research linking biological correlates to behavior.

Developmental dyscalculia and brain laterality.

The correlation between arithmetic dysfunction and brain laterality was studied in 25 children with developmental dyscalculia (DD). The children were tested on a standardized arithmetic battery and underwent a neurological and neuro-psychological evaluation. A diagnosis of left hemisphere dysfunction (n = 13) was based on right side soft neurological signs, performance IQ (PIQ) > verbal IQ (VIQ), dyslexia and intact visuo-spatial functions. The criteria for right hemisphere dysfunction (n = 12) were left body signs, VIQ > PIQ, impaired visuo-spatial functions and normal language skills. The groups were similar for age, gender, and socio-economic status. Our results showed that both groups scored more than 2 SD below the mean adjusted score on the arithmetic battery, but the left group was significantly worse in 3 areas: mastery of addition/subtraction, complex multiplication and division and visuo-spatial errors (p < 0.05). The data indicate that dysfunction of either hemisphere hampers arithmetic acquisition, but arithmetic impairment is more profound with left hemisphere dysfunction.

Arithmetic skills in kindergarten children with developmental language disorders.

Although arithmetic is not a language-based skill, a specific learning disability in arithmetic--dyscalculia--is commonly seen in children with developmental language disorders (DLD). The object of this study was to assess whether kindergarten children with DLD have impaired arithmetic skills and, if so, to correlate the pattern of dysfunction with language syndromes. Forty-two children with DLD attending mainstream kindergartens, and their matched controls, underwent an arithmetic battery, neurological examination, intelligence quotient (IQ) test (WPPSI/WISC-R) and language assessment (CELF-R).* Attention deficit hyperactivity disorder (ADHD) was diagnosed by psychological assessment and behaviour questionnaires. Results showed that children with DLD were similar to controls on performance IQ (104.2+/-12.1 and 109.4+/-12.7 respectively, p = NS), but inferior on both the CELF-R expressive (74.8+/-9.3 vs 95.2+/-15.1, p < 0.01) and receptive (77.5+/-10.0 vs 87.8+/-12.3, p < 0.01) language scores. Their performance on the arithmetic battery was also significantly poorer: 61.2+/-17.7 vs 77.4+/-13.7, p < 0.01. Low scores in reasoning principles and arithmetic operations were associated with both receptive and expressive language impairment, while poor performance on counting principles was primarily associated with expressive deficits. Mild motor signs and ADHD were more frequent in children with DLD (p < 0.01 and < 0.05, respectively). We concluded that the arithmetic impairment in children with DLD is pervasive, affecting a broad spectrum of skills. Whereas impairment of most arithmetic skills is associated with global language disturbances, counting correlates primarily with expressive language deficits. Anticipatory guidance by physicians will better prepare parents and educators for the multiple challenges facing children with DLD.

Cognition, attention, and behavior in Prader-Willi syndrome.

We studied the academic, cognitive, and behavior profile of 18 patients with Prader-Willi syndrome. All had severe learning disabilities in arithmetic and writing, and the majority were also dyslexic. Their average Full-Scale IQ was 73.7 +/- 8.9, which was 1 SD below normal range, whereas their performance on executive, memory, and visuospatial tasks ranged from 2.1 to 7.0 SD below the expected means. Behavioral problems were measured using the Child Behavior Checklist, on which the majority scored in the pathologic range for social and attention problems, delinquent and aggressive behavior, somatic complaints, and thought problems. Genotypes of the children did not predict cognitive or behavioral profile, nor could behavior be associated with parameters of weight or IQ. In summary, we found that patients with Prader-Willi syndrome have profound learning disabilities and cognitive deficits, greater than expected for their IQ. Behavioral problems, including attention-deficit hyperactivity disorder (ADHD), are also prevalent and impede the overall management of this group of patients. The genotypes were not helpful in predicting cognitive or behavioral patterns.

Attention-deficit hyperactivity disorder and developmental right-hemisphere syndrome: congruence and incongruence of cognitive and behavioral aspects of attention.

We studied clinical aspects of attention in three groups: children with developmental right-hemisphere syndrome and attention-deficit hyperactivity disorder (ADHD), children with ADHD only, and normal controls. The three groups (N = 54) were case-matched for age, sex, IQ, hand dominance, and socioeconomic status. ADHD was diagnosed clinically using the Diagnostic and Statistical Manual of Mental Disorders-III-Revised criteria and the Conners' Abbreviated Teacher Questionnaire. Additional aspects of attention and behavior were measured by the Child Behavior Checklist, a low-cognitive-load continuous performance task, and the visual target cancellation test (paper and pencil). Although the Child Behavior Checklist profile of attentional deficits in the two clinical groups was similar, we found that the developmental right-hemisphere syndrome group was more severely impaired on parameters of attention measured by the continuous performance task and visual target cancellation test than the children with ADHD. We conclude that the profile of attentional deficits in developmental right-hemisphere syndrome is different than that seen in children with ADHD only, possibly reflecting disparate neurologic underpinnings for the two syndromes.

Developmental dyscalculia.

Developmental dyscalculia is a specific learning disability affecting the acquisition of arithmetic skills in an otherwise-normal child. Although poor teaching, environmental deprivation, and low intelligence have been implicated in the etiology of developmental dyscalculia, current data indicate that this learning disability is a brain-based disorder with a familial-genetic predisposition. The neurologic substrate of developmental dyscalculia is thought to involve both hemispheres, particularly the left parietotemporal areas. Developmental dyscalculia is a common cognitive handicap; its prevalence in the school population is about 5-6%, a frequency similar to those of developmental dyslexia and attention-deficit-hyperactivity disorder. Unlike these, however, it is as common in females as in males. Developmental dyscalculia frequently is encountered in neurologic disorders, examples of which include attention-deficit-hyperactivity disorder, developmental language disorder, epilepsy, and fragile X syndrome. The long-term prognosis of developmental dyscalculia is unknown; it appears, however, to persist, at least for the short-term, in about half of affected preteen children. The consequences of developmental dyscalculia and its impact on education, employment, and psychologic well-being of affected individuals are unknown.

Attention deficit disorder: association with familial-genetic factors.

The etiology of attention deficit disorder and hyperactivity (ADDH) is controversial because both biologic and social factors have been postulated. To study such factors, we undertook a referral study based on an entire cohort (N = 6,950) of children born in Jerusalem in 1976. Of 479 children referred for learning disabilities, hyperactivity, and behavioral problems, 381 were available for study. Information regarding obstetric, developmental, and family histories was obtained by a detailed, structured interview. A DSM-III-based questionnaire for ADDH was completed by parents and teachers. Each child underwent neurologic examination and 133 had IQ testing. Of these children, 145 fulfilled the criteria for ADDH. Our results revealed a number of significant familial-genetic factors: boys outnumbered girls by 3:1, 30% of ADDH children had siblings with learning disabilities (P less than .001); and ADDH children clustered within families of North African descent (P less than .001). The only significant developmental factor was delayed language development. Of numerous pre- and peri-natal factors investigated, only intrauterine growth retardation was significantly associated with ADDH. No correlation was found between ADDH and IQ, parental age, years of education, profession, and language spoken at home. Our study supports the hypothesis that familial-genetic factors are contributory to ADDH.

Development of color association in normal and neurologically impaired children.

Color association, defined as the ability to identify the characteristic color of familiar objects, was studied in 2 groups of brain-damaged children with language or nonlanguage impairment and in a group of control patients. The performance of the 16 control children, 3.5-4.5 years of age, was compared with that of 31 patients, 4.5-5.5 years of age; their scores were 52.4 +/- 31.3 (mean +/- SD) and 85.9 +/- 13.1, respectively (p less than 0.005). Seventeen dysphasic, brain-damaged children and 11 age-matched children with neurologic deficits but without language delay were examined. Their scores were 57.7 +/- 11.7 and 70.6 +/- 21.9, respectively (p less than 0.05). Finally, each of the brain-damaged groups was compared with age-matched controls. Although the control children performed far better than the dysphasic children (77.6 +/- 20.9 and 57.5 +/- 11.7, respectively, p less than 0.001), there was no significant difference between controls and neurologically impaired children without language delay (77.6 +/- 20.9 and 70.6 +/- 21.9, respectively). We conclude that color association in normal children is already operative at 3.5 years and approaches maturity by 4.5-5.5 years. This function was preserved in neurologically impaired children without language delay but was significantly distrubed in the dysphasic children; therefore, the use of color should be assessed in the habilitation of children.

Oculomotor apraxia: the presenting sign of Gaucher disease.

Oculomotor apraxia may be idiopathic or a symptom of a variety of diseases. In Gaucher disease, oculomotor deficit is characterized by a failure of volitional horizontal gaze with preservation of vertical movements. We present 2 sisters, 6 1/2 and 5 1/2 years of age, in whom the presenting sign was oculomotor apraxia. Oculomotor apraxia has not been previously reported as the presenting manifestation of Gaucher disease.

Developmental dyscalculia and medical assessment.

Developmental dyscalculia (DC) is a primary cognitive disorder of childhood manifested by disturbance of arithmetic ability. As an isolated learning disability (LD), it is usually treated by remedial education and not referred for further medical evaluation. We examined a group of 7 third-grade children with DC attending a mainstream school who had not progressed academically in spite of specific special education intervention. We were able to identify in all 7 children neurological conditions that had direct bearing on the children's cognitive disabilities and remedial programs. One child had petit mal seizures, another developmental Gerstmann syndrome, a third had dyslexia for numbers, and 4 children had attention deficit disorders without hyperactivity. Based on this experience, we suggest that the indications for medical or neurological assessment be broadened to include children who are not improving academically in spite of appropriate professional intervention.

Developmental right-hemisphere syndrome: clinical spectrum of the nonverbal learning disability.

We report the clinical characteristics of the developmental right-hemisphere syndrome (DRHS), a nonverbal learning disability, in 20 children (9 girls and 11 boys; mean age = 9.5 years) who also manifested attention-deficit/hyperactivity disorder (ADHD), severe graphomotor problems, and marked slowness of performance. Diagnostic criteria for this study included (a) emotional and interpersonal difficulties; (b) paralinguistic communication problems; (c) impaired visuospatial skills, verbal IQ > performance IQ, and verbal IQ > or = 85; and either (d) dyscalculia or (e) neurological signs on the left side of the body. In this group, verbal IQ was significantly higher than performance IQ (106.6 +/- 13.0 vs. 85.1 +/- 13.1, respectively, p < .01). Arithmetic was the lowest score among the verbal subtests (7.8 +/- 3.5, p < .01) and Geometrical Design was the lowest score among the performance subtests (5.8 +/- 1.7). Thirteen children had soft neurological signs on the left side of the body. ADHD was seen in all 20 children, marked slowness of performance in 16, and severe graphomotor problems in 18. The latter two features have not been previously described as part of DRHS.

Developmental dyscalculia is a familial learning disability.

Whereas current evidence attests to a genetic component in the etiology of dyslexia and attention-deficit/hyperactivity disorder (ADHD), little is known about the role of genetics in developmental dyscalculia (DC). The objective of this study was to determine the familial aggregation of DC. Siblings and parents of children with DC were assessed for arithmetic, reading and attention disorders. The criteria for DC were an IQ higher than 85, poor performance in arithmetic, and a significant discrepancy between arithmetic achievement and IQ. The study group was composed of 39 children with DC, 21 mothers, 22 fathers, 90 siblings, and 16 second-degree relatives. We found that 66% of mothers, 40% of fathers, 53% of siblings, and 44% of second-degree relatives had DC. The intraclass correlation between the sib pairs was .27. A 95% confidential interval (CI) for the prevalence of DC among siblings of DC probands (see Note 1) ranged from 40% to 64%, indicating a familial prevalence almost tenfold higher than expected for the general population. IQ and attention problems were not risk factors for DC. We conclude that DC, like other learning disabilities, has a significant familial aggregation, suggesting a role for genetics in the evolution of this disorder.

[Prader-Willi syndrome: medical, emotional and cognitive facets].

Prader-Willi syndrome, first described in 1956, is characterized by marked hypotonia, hyperphagia, severe obesity, short stature, hypogonadism, orthopedic problems, breathing-related sleep disorders, mild to moderate mental retardation and behavioral abnormalities. The incidence of this syndrome, an expression of a genetic imprinting error in chromosome 15, is 1:10,000-1:25,000. We describe the medical, emotional and cognitive parameters of 34 patients in our multidisciplinary clinic for Prader-Willi syndrome. Their ages range from 5 months to 40 years and 20 are males. Excessive weight gain started at the age of 6 years, increasing to 170-370% of that predicted by height and age and short stature started after the age of 12. All males have hypogonadism; 6 patients have scoliosis. Breathing-related sleep disorders have occurred in 15. Children above the age of 8 years underwent neuropsychological assessment: half (9/18) have borderline intelligence while a quarter have low-normal intelligence and the remainder mild to moderate mental retardation. Behavioral and social problems are common, and become more prominent during adolescence. ADHD was diagnosed in 10/18.

[Attention deficit disorder: attentional characteristics of developmental right hemisphere syndrome].

Developmental right hemisphere syndrome (DRHS) is characterized by emotional and interpersonal difficulties, attention deficit hyperactivity disorder (ADHD), visuo-spatial handicaps, subtle left body neurologic signs and failure in nonverbal academic domains, especially arithmetic. Concurrence of ADHD and DRHS is not surprising because research has implicated dysfunction of the right hemisphere in both syndromes. Furthermore, the right hemisphere has more brain areas devoted to attentional processing, making it more important and more vulnerable in attentional problems. We describe the clinical parameters of DRHS as exemplified by 2 cases, a boy and a girl, both 13 years old. They participated in a study group in which attention and speed of performance were assessed in children with DRHS and were compared to children with ADHD and to a control group. A tendency to overfocusing, difficulty in inhibition, perseverative behaviors, stereotypy, and slowness and absence of hyperactivity characterized the DRHS group. These behaviors led us to hypothesize that the attentional symptoms in DRHS define a specific subgroup of ADHD which requires a different therapeutic approach.

Isolated mild white matter signal changes in preterm infants: a regional approach for comparison of cranial ultrasound and MRI findings.

OBJECTIVE: To compare echogenicity detected using cranial ultrasound (cUS) and diffuse excessive high signal intensity (DEHSI) detected using magnetic resonance imaging (MRI) by identical region-based scoring criteria in preterm infants. To explore the association between these white matter (WM) signal changes with early neurobehavior. STUDY DESIGN: Forty-nine pre-selected premature infants with only echogenicity on a first routine cUS1 underwent MRI and a repeated cUS2 at term equivalent age. Echogenicity and DEHSI were graded in various brain areas and diffusivity values were calculated. Neurobehavior was assessed using the Rapid Neonatal Neurobehavioral Assessment Procedure. RESULT: WM signal changes were significantly higher on cUS1 than cUS2; and higher in MRI than cUS2 in posterior regions. Infants with DEHSI demonstrated reduced tissue integrity. Imaging findings were not correlated with early neurobehavior. CONCLUSION: Echogenicity and DEHSI likely represent the same phenomenon. Reduction of over-interpretation of WM signal changes may help define criteria for the judicious use of imaging in routine follow-up of premature infants.