Behavioral phenotypes of genetic syndromes: a reference guide for psychiatrists

Clinical Assessment of Young Children

Mental health assessment of young children provides valuable information to shape a formulation and guide treatment. Early childhood mental health assessment can occur in an increasing number of settings beyond traditional mental health practices, including childcare settings, primary care settings, and other settings where children and family are regularly seen. Although many of the components of an early childhood mental health assessment are included in the assessment of older children, assessment of very young children requires some specific developmental adjustments and additional considerations including attention to the parent-child relationship and caregiving context and rapid development.

Numerical and area comparison abilities in Down syndrome

Individuals with Down syndrome (DS) have great difficulty in learning mathematics. In recent years, research has focused on investigating whether precursors of later mathematical competence, such as estimating and comparing numerosities, are preserved in DS. Although studies have suggested a strong relationship between the ability to compare continuous quantities (e.g., area of an object) and that of comparing numerosities, it is still unknown whether this ability is preserved in DS. This study investigated the abilities of individuals with DS to compare area and number and contrasted them with those of two control groups of typically developing individuals. Participants were 16 individuals with DS, 16 typically developing individuals matched by mental age (MA group), and 16 typically developing individuals matched by chronological age (CA group). All participants performed two eye-tracking tasks: an Area Comparison Task (ACT) and a Number Comparison Task (NCT). Stimuli in the two tasks differed in the same ratio to enable comparison of individual performance across both tasks. The results showed that in general, the performance of the three groups was better in the ACT than in the NCT. Critically, performance of individuals with DS in both tasks was consistent with that of individuals with the same MA. The study shows that the abilities to compare area and numerosity are both preserved in DS, and that individuals with this syndrome, like typically developing individuals, show better performance in comparing area than number.

Patterns of differences in wayfinding performance and correlations among abilities between persons with and without Down syndrome and typically developing children

Down syndrome (DS) impacts several brain regions including the hippocampus and surrounding structures that have responsibility for important aspects of navigation and wayfinding. Hence it is reasonable to expect that DS may result in a reduced ability to engage in these skills. Two experiments are reported that evaluated route-learning of youth with DS, youth with intellectual disability (ID) and not DS, and typically developing (TD) children matched on mental age (MA). In both experiments, participants learned routes with eight choice point presented via computer. Several objects were placed along the route that could be used as landmarks. Participants navigated the route once with turn indicators pointing the way and then retraced the route without them. In Experiment 1 we found that the TD children and ID participants performed very similarly. They learned the route in the same number of attempts, committed the same number of errors while learning the route, and recalled approximately the same number of landmarks. The participants with DS performed significantly worse on both measures of navigation (attempts and errors) and also recalled significantly fewer landmarks. In Experiment 2, we attempted to reduce TD and ID vs DS differences by focusing participants’ attention on the landmarks. Half of the participants in each group were instructed to identify the landmarks as they passed them the first time. The participants with DS again committed more errors than the participants in the ID and TD groups in the navigation task. In addition, they recalled fewer landmarks. While landmark identification improved landmark memory for both groups, it did not have a significant impact on navigation. Participants with DS still performed more poorly than did the TD and ID participants. Of additional interest, we observed that the performance of persons with DS correlated with different ability measures than did the performance of the other groups. The results the two experiments point to a problem in navigation for persons with DS that exceeds expectations based solely on intellectual level.

Visuo-spatial ability in individuals with Down syndrome: is it really a strength?

Down syndrome (DS) is associated with extreme difficulty in verbal skills and relatively better visuo-spatial skills. Indeed, visuo-spatial ability is often considered a strength in DS. However, it is not clear whether this strength is only relative to the poor verbal skills, or, more impressively, relative to cognitive ability in general. To answer this question, we conducted an extensive literature review of studies on visuo-spatial abilities in people with Down syndrome from January 1987 to May 2013. Based on a general taxonomy of spatial abilities patterned after Lohman, Pellegrino, Alderton, and Regian (1987) and Carroll (1993) and existing studies of DS, we included five different domains of spatial abilities - visuo-spatial memory, visuo-spatial construction, mental rotation, closure, and wayfinding. We evaluated a total of 49 studies including 127 different comparisons. Most comparisons involved a group with DS vs. a group with typical development matched on mental age and compared on a task measuring one of the five visuo-spatial abilities. Although further research is needed for firm conclusions on some visuo-spatial abilities, there was no evidence that visuo-spatial ability is a strength in DS relative to general cognitive ability. Rather, the review suggests an uneven profile of visuo-spatial abilities in DS in which some abilities are commensurate with general cognitive ability level, and others are below.

Rule-based category learning in Down syndrome

Rule-based category learning was examined in youths with Down syndrome (DS), youths with intellectual disability (ID), and typically developing (TD) youths. Two tasks measured category learning: the Modified Card Sort task (MCST) and the Concept Formation test of the Woodcock-Johnson-III ( Woodock, McGrew, & Mather, 2001 ). In regression-based analyses, DS and ID groups performed below the level expected for their nonverbal ability. In cross-sectional developmental trajectory analyses, results depended on the task. On the MCST, the DS and ID groups were similar to the TD group. On the Concept Formation test, the DS group had slower cross-sectional change than the other 2 groups. Category learning may be an area of difficulty for those with ID, but task-related factors may affect trajectories for youths with DS.

Attention deficit

Primary attention-deficit/hyperactivity disorder (ADHD) is a familial neurodevelopmental disorder involving the frontostriatal pathways and probably connections with the cerebellum and parietal lobe. ADHD is a polygenetic disorder involving predominantly catecholaminergic receptors and transporters. Though more common in school age children, ADHD may persist into adolescence and adulthood. Comorbidity with other disruptive behavior disorders, anxiety disorders, mood disorders, and learning disability is common. Secondary problems with attention are associated with neurological disorders that involve damage to the frontal lobes, drugs and toxins, and some genetic syndromes. Questionnaires are helpful in the diagnosis and follow-up of ADHD, and neuropsychological assessment can be useful for assessing cognitive function. Behavioral therapies are usually combined with medication for treatment of ADHD. Problems with attention are more responsive to treatment with stimulants, but nonstimulant medications such as atomoxetine, and possibly other drugs, are also effective and may be particularly useful in children and adolescents with comorbidity. The response to pharmacotherapy is better in patients with primary ADHD compared to those with secondary problems with attention.

Genetic counseling in psychiatry

While psychiatrists may commonly discuss family history in clinical practice, there has been little systematic research documenting the role and effectiveness of genetic counseling for psychiatric disorders. In the coming years, the expected identification of susceptibility genes for psychiatric disorders may bring new opportunities and expectations from patients and families for the clinical translation of research findings in psychiatric genetics. We review evidence for possible increasing demand for genetic counseling, particularly if specific genes related to psychiatric disorders are identified. We then explore both the potential role of genetic counseling for psychiatric disorders and the issues involved in conveying genetic information in the clinical setting. Further research regarding the effectiveness of counseling interventions, as well as additional efforts directed at genetics education for clinicians, will be needed if emerging advances in genetic research are to be incorporated into clinical practice.

Children with Prader-Willi syndrome vs. Williams syndrome: indirect effects on parents during a jigsaw puzzle task

BACKGROUND

Genetic disorders predispose individuals to exhibit characteristic behaviours, which in turn elicit particular behaviours from others. In response to the strength of Prader-Willi syndrome (PWS) and weakness of Williams syndrome (WS) in visual-spatial tasks such as jigsaw puzzles, parents' behaviours can be affected by their child's level of puzzle ability or syndrome diagnosis.

METHODS

Children were asked to complete two jigsaw puzzles (one with the experimenter and the other with the parent) for 5 min each. Frequencies of parental helping and reinforcement behaviours, along with ratings of parental directiveness, were examined as parents interacted with their children on a jigsaw puzzle task. Within each aetiological group, correlates of parental behaviours with child characteristics were also examined.

RESULTS

Compared to parents of children with PWS, parents of children with WS engaged in a more directive style of interaction, and provided more help and reinforcement. Relative to parents of children with higher puzzle abilities (from both aetiologies), parents of children with lower abilities also showed the same pattern. Both the child's aetiology and puzzle abilities were important in predicting parents' directiveness and helping and reinforcement behaviours. Within the PWS group, parents' behaviours correlated negatively with the child's puzzle abilities and general cognitive functioning; no such relations occurred in the WS group.

CONCLUSIONS

Parents' behaviours were affected by both the child's diagnosis and actual puzzle abilities, suggesting important implications for understanding and intervening with parents and children with different genetic syndromes.

Disorders of attention or learning in neurodevelopmental disorders

Disorders of attention or learning commonly accompany neurodevelopmental disorders. The evaluation and diagnosis of these disorders is complex and does not always follow techniques used for typically developing children. These disorders are often underappreciated and inadequately addressed because they are overshadowed by the neurodevelopmental disorder. Nevertheless, failure to recognize, diagnose, and manage these disorders may result in unsuccessful community integration.

Down syndrome and comorbid autism-spectrum disorder: Characterization using the aberrant behavior checklist

To report on the cognitive and behavioral attributes of 61 children with Down syndrome (DS) and autistic-spectrum disorder (ASD) according to DSM-IV criteria; to determine the utility of the aberrant behavior checklist (ABC) to characterize these subjects for research purposes; and to test the hypothesis that subjects with DS + ASD could be distinguished from their typical DS peers using the ABC. Cross-sectional design. Cases with DS + ASD (N = 61), comparison group of DS + stereotypy movement disorder (SMD) (N = 26) and typical DS controls without behavior problems (N = 44) were ascertained and enrolled sequentially upon presentation to a DS clinic at an academic medical center over a 10-year period from 1991 to 2001. All subjects underwent neurodevelopmental and medical evaluation, and standardized cognitive testing. The parents provided responses to standardized behavioral questionnaires. Cognitive function (IQ) differed markedly across the three groups. The Lethary and Stereotypy subscales of the ABC were highly significant (P < 0.001) in distinguishing the three groups from one another. Within the ASD group differences were apparent by DSM-IV type on the Lethargy subscale, which reached significance, ANOVA (F = 0.002) and t-test (Autism > PDD, P = 0.005; PDD < CDD, P = 0.002). Using a multivariate regression model, the ABC scales alone explained 62% of variance of ASD outcome; addition of demographic variables explained up to 68% of the variance. There is good correlation between DSM-IV criteria for autism and subscales scores on the ABC in subjects with DS. This study demonstrates the feasibility of using the ABC to characterize the neurobehavioral phenotype of a cohort of children with trisomy 21 and ASD for ongoing research purposes.

Attention-deficit/hyperactivity disorder in children and adolescents

ADHD is a common developmental disorder frequently associated with additional neurologic and psychiatric disorders. Stimulant medication is an effective first-line therapy for most children with ADHD. Current research is defining the genetic and neurobiologic basis for this disorder.

Depression in children and adolescents

Depression is a common problem in children and adolescents. The disorder may be overlooked because of the prominent irritability seen in children with depression and because of the perception that moodiness is a normal phase of childhood. Depression frequently is associated with other psychiatric problems and neurologic disorders. Therapy consists of psychotherapy and medication, with SSRIs the first choice for pharmacotherapy.

Personality and stereotype in osteogenesis imperfecta: behavioral phenotype or response to life's hard challenges?

Fifty-five adults with osteogenesis imperfecta [OI] types III and IV were interviewed to chronicle their medical, personal, and social experiences in living with OI. Subjects were recruited through the Osteogenesis Imperfecta Foundation, through physician referrals, and through other persons with OI. One purpose of the research was to examine the stereotypes of high intelligence and euphoric personality often attributed to persons with OI, and to explore whether these characteristics might constitute a behavioral phenotype. Participants were observed by the researcher to be characteristically bright, talkative, articulate, "up" emotionally, and accomplished. In fact, most of the persons illustrated well the characteristics of the stereotype. Participants suggested and described life experiences and difficult medical and social challenges which they felt could contribute to the development of the attributed characteristics. The history of the "euphoric" attribution is traced. Many participants expressed derision concerning this attribution. The commonly understood meaning of this term trivializes the years of painful medical procedures, suffering, and related hardships experienced by subjects in their lives. I suggest that the concept of "resilience" offers a more appropriate context for related future research with this population. The consideration of the exceptional challenges faced by persons with OI and others with such demanding medical conditions throughout their life cycles would add a significant environmental dimension to the study of behavioral phenotypes.

A rational approach to the child with mental retardation for the paediatrician

Mental Retardation (MR) is a problem encountered in almost all paediatric clinical settings. The assessment of a child with MR is a common diagnostic and management dilemma for paediatricians. The field of MR research is currently in a state of flux regarding not just our understanding of the condition, but also in the language and the processes we use in naming, defining and describing MR. This article will provide a better understanding and a rational approach toward MR. Prevalence rates for MR are variable in the literature and may be attributable to the variation in major classification systems and the diversity in study operation definitions and methodologies. Etiologies of MR are diverse and include many different influences. MR most often presents during infancy or preschool years as developmental delay. There is no universally accepted approach to the etiological work-up of mental retardation. The number of medical conditions associated with MR that are completely treatable by medical means remains small. The paediatrician plays a key role establishing short and long term treatment goals, as well as providing support to families who have children with MR.

Beyond the disability: recognizing mental health issues among persons with intellectual and developmental disabilities

Current societal changes mean increased possibilities for individuals with I/DD to participate in work, family, and community life. However, as individuals with I/DD have at least the same prevalence of mental health disorders as the general population and possibly an increased susceptibility to some mental health disorders, their ability to participate in work, housing, and social opportunities is hampered. It is important to improve nursing education about the specific issues of mental health care of individuals with I/DD. An important area for nursing research and education are improved clinical and practice guidelines. Research on medications and other therapies in mental health care of individuals with I/DD is limited and has methodological limitations. Nursing education and training are holistic, and nursing has the potential of positive impact on practice, education, and research that will improve the mental health care of individuals with I/DD.

The epidemiology of mental retardation: challenges and opportunities in the new millennium

There are a number of problems and challenges in relating the science of epidemiology to mental retardation (MR). These relate to how MR is defined and classified and how these definitions may change over time. These as well as other differences in ascertainment sources and methods need to be considered when comparing MR prevalence over time and place. On the other hand, advances in technology also provide new and efficient methods of data collection both by data linkage and by use of web-based methods to study rare diseases. While prevalence studies have not been individually reviewed, we have examined the range of data including recent studies relating to how prevalence differs according to age, gender, social class and ethnicity. Some problems with available etiological classification systems have been identified. Recent etiological studies, most of which use different classification systems, have been reviewed and explanations have been postulated to account for differences in results. Individual risk factors for MR are considered whilst the option of considering a population as opposed to a high risk strategy to MR prevention is raised. This might well involve improving the social milieu surrounding the occurrence of individual risk factors. The impact of biotechnological advances such as antenatal and neonatal screening and assisted reproduction on MR are discussed. The issue of how inequalities in access to technology may impact on case identification and even have the potential to further widen inequalities is raised. The importance of extending the use of epidemiological tools to study the social, health and economic burden of MR is also emphasized. However, in order to apply to MR the "prevention-intervention-research" cycle, which surely underpins all epidemiology, it is vital to ensure that the methodological challenges we raise are adequately addressed.

Schizophrenia-like illness in velo-cardio-facial syndrome: a genetic subsyndrome of schizophrenia?

BACKGROUND

The study of genetic illnesses that have a behavioral phenotype resembling psychosis can provide important insights into the genetic basis of psychotic disorders and their patho-mechanisms. An important example of such a genetic disorder is the velo-cardio-facial syndrome (VCFS) associated with 22q11 microdeletion.

CASE REPORT

The case of a 22-year-old male, who had the typical genotype and phenotype of VCFS and developed a psychotic illness characterized by withdrawal, catatonic posturing, inappropriate affect, stereotyped behavior, negativism and poverty of speech, is described. He had a partial response to an atypical neuroleptic, but developed myoclonus that was controlled with an anticonvulsant.

CONCLUSION

The association of VCFS with schizophrenia-like psychosis is worthy of further study as it may provide insights into the molecular basis of neurodevelopment and its aberrations in psychotic disorders.