The behavioral profile of children aged 1-5 years with sex chromosome trisomy (47,XXX, 47,XXY, 47,XYY)

Social Communication in Young Children With Sex Chromosome Trisomy (XXY, XXX, XYY): A Study With Eye Tracking and Heart Rate Measures

OBJECTIVE

Children with sex chromosome trisomy (SCT) have an increased risk for suboptimal development. Difficulties with language are frequently reported, start from a very young age, and encompass various domains. This cross-sectional study examined social orientation with eye tracking and physiological arousal responses to gain more knowledge on how children perceive and respond to communicative bids and evaluated the associations between social orientation and language outcomes, concurrently and 1 year later.

METHOD

In total, 107 children with SCT (33 XXX, 50 XXY, and 24 XYY) and 102 controls (58 girls and 44 boys) aged between 1 and 7 years were included. Assessments took place in the USA and Western Europe. A communicative bids eye tracking paradigm, physiological arousal measures, and receptive and expressive language outcomes were used.

RESULTS

Compared to controls, children with SCT showed reduced attention to the face and eyes of the on-screen interaction partner and reduced physiological arousal sensitivity in response to direct versus averted gaze. In addition, social orientation to the mouth was related to concurrent receptive and expressive language abilities in 1-year-old children with SCT.

CONCLUSIONS

Children with SCT may experience difficulties with social communication that extend past the well-recognized risk for early language delays. These difficulties may underlie social-behavioral problems that have been described in the SCT population and are an important target for early monitoring and support.

Early Social Behavior in Young Children with Sex Chromosome Trisomies (XXX, XXY, XYY): Profiles of Observed Social Interactions and Social Impairments Associated with Autism Spectrum Disorder (ASD)

Individuals with Sex Chromosome Trisomies (SCT; XXX, XXY, XYY) have an increased vulnerability for developing challenges in social adaptive functioning. The present study investigates social interaction behavior in the context of varying social load, and Autism Spectrum Disorder (ASD) symptomatology in young children aged 1-7.5 years old, with SCT (N = 105) and control children (N = 101). Children with SCT show less interaction behaviors and more social withdrawal, as compared to their control peers, which were most evident in the high social load condition. Second, social impairments related to ASD are more prevalent, as compared to controls (27.1% at clinical level). These findings stress the importance of early monitoring and (preventive) support of early social development in young children with SCT.

[Formula: see text] Emotional reactivity and expressivity in young children with sex chromosome trisomies: evidence from psychophysiological and observational data

Although sex chromosomal trisomies (SCT) in children are highly prevalent and associated with an increased risk for neurodevelopmental difficulties including socio-emotional problems, little is known about underlying mechanisms that could drive this risk. Studying emotional reactivity and expressivity of young children with SCT in early childhood could identify deviations in early emotional development and potentially serve as risk markers to guide clinical care in developing interventions. Participants in the current study were 90 SCT children and 97 population-based controls, aged 1 to 7 years, who experienced a stress-inducing event in which physiological (heart rate) and observational data (expression of negative emotions) were collected. Results showed early disturbances in the emotion system of young children with SCT, in terms of blunted but prolonged emotional reactivity and a reduced emotional expressivity in response to stress. Further, the concordance between emotional reactivity (arousal response) and expressivity was significantly lower in SCT, compared to controls. Given the significant impact of emotions on adaptive day-to-day functioning, deviations in processing emotions could be an important underlying mechanism in explaining the heterogeneity and variability in developmental outcomes often described in individuals with SCT.

Neurocognitive and behavioral development in young children (1-7 years) with sex chromosome trisomy

Investigating sex chromosome trisomies (SCTs) may help in understanding neurodevelopmental pathways underlying the risk for neurobehavioral problems and psychopathology. Knowledge about the neurobehavioral phenotype is needed to improve clinical care and early intervention for children with SCT. This is especially relevant considering the increasing number of early diagnosed children with the recent introduction of noninvasive prenatal screening. The TRIXY Early Childhood Study is a longitudinal study designed to identify early neurodevelopmental risks in children with SCT, aged 1-7 years. This review summarizes the results from the TRIXY Early Childhood Study, focusing on early behavioral symptoms in areas of autism spectrum disorder, attention-deficit hyperactivity disorder, and communication disorders, and underlying neurocognitive mechanisms in domains of language, emotion regulation, executive functioning, and social cognition. Behavioral symptoms were assessed through structured behavior observation and parental questionnaires. Neurocognition was measured using performance tests, eyetracking, and psychophysiological measures of arousal. In total, 209 children aged 1-7 years were included: 107 children with SCT (33 XXX, 50 XXY, and 24 XYY) and 102 age-matched population controls. Study outcomes showed early behavioral symptoms in young children with SCT, and neurocognitive vulnerabilities, already from an early age onward. Neurobehavioral and neurocognitive difficulties tended to become more pronounced with increasing age and were rather robust, independent of specific karyotype, pre/postnatal diagnosis, or ascertainment strategy. A more longitudinal perspective on neurodevelopmental 'at-risk' pathways is warranted, also including studies assessing the effectiveness of targeted early interventions. Neurocognitive markers that signal differences in neurodevelopment may prove to be helpful in this. Focusing on early development of language, social cognition, emotion regulation, and executive functioning may help in uncovering early essential mechanisms of (later) neurobehavioral outcome, allowing for more targeted support and early intervention.

Structural and pragmatic language in young children with sex chromosome trisomy (XXX, XXY, XYY): Predictive value for neurobehavioral problems one year later

Objective: To investigate pragmatic language abilities in young children with an increased risk for adverse neurobehavioral and neurocognitive outcomes due to an extra X or Y chromosome (sex chromosome trisomy; SCT) and to investigate to what degree early structural and pragmatic language abilities are predictive of neurobehavioral problems one year later. Method: In total, 72 children with SCT and 71 controls aged 3-7 years were included. Language assessments included parent-reported pragmatic language skills and direct assessment of structural language abilities. Parent-reported behavioral outcomes were measured one year after the initial language assessment. Results: Children with SCT demonstrated weaker pragmatic language skills compared to controls. These differences were not driven by karyotype, time of diagnosis, or ascertainment bias and irrespective of the presence of structural language impairment. Odds of having pragmatic difficulties was 23 times higher in the SCT group, with 25% of the children not meeting age-expectations. In addition, language, in particular pragmatic language, was an important predictor for later affective, oppositional defiant, pervasive developmental, attention deficit, and social-emotional problems in young children with SCT. Conclusions: This study is one of the first studies that directly illustrates the relationship between language and behavioral outcomes in children with SCT. Our results stress the importance to closely monitor pragmatic language in addition to structural language in clinical care of children with SCT, as pragmatic language abilities could serve as an early marker for children at risk for developing behavioral problems.

Prenatal diagnosis of sex chromosome aneuploidy-What do we tell the prospective parents?

Sex chromosome aneuploidy (SCA) can be detected on prenatal diagnostic testing and cell free DNA screening (cfDNA). High risk cfDNA results should be confirmed with diagnostic testing. This summary article serves as an update for prenatal providers and assimilates data from neurodevelopmental, epidemiologic, and registry studies on the most common SCA. This information can be helpful for counseling after prenatal diagnosis of sex chromosome aneuploidy. Incidence estimates may be influenced by ascertainment bias and this article is not a substitute for interdisciplinary consultation and counseling.

The impact of sex chromosome trisomies (XXX, XXY, XYY) on gaze towards faces and affect recognition: a cross-sectional eye tracking study

BACKGROUND

About 1:650-1000 children are born with an extra X or Y chromosome (47,XXX; 47,XXY; 47,XYY), which results in a sex chromosome trisomy (SCT). This international cross-sectional study was designed to investigate gaze towards faces and affect recognition during early life of children with SCT, with the aim to find indicators for support and treatment.

METHODS

A group of 101 children with SCT (aged 1-7 years old; Mage= 3.7 years) was included in this study, as well as a population-based sample of 98 children without SCT (Mage= 3.7). Eye gaze patterns to faces were measured using an eye tracking method that quantifies first fixations and fixation durations on eyes of static faces and fixation durations on eyes and faces in a dynamic paradigm (with two conditions: single face and multiple faces). Affect recognition was measured using the subtest Affect Recognition of the NEPSY-II neuropsychological test battery. Recruitment and assessment took place in the Netherlands and the USA.

RESULTS

Eye tracking results reveal that children with SCT show lower proportion fixation duration on faces already from the age of 3 years, compared to children without SCT. Also, impairments in the clinical range for affect recognition were found (32.2% of the SCT group scored in the well below average range).

CONCLUSIONS

These results highlight the importance to further explore the development of social cognitive skills of children with SCT in a longitudinal design, the monitoring of affect recognition skills, and the implementation of (preventive) interventions aiming to support the development of attention to social important information and affect recognition.

Children's Behavior and Maternal Parenting Stress in Young Children With Sex Chromosome Trisomies

OBJECTIVE

Children and adolescents with sex chromosome trisomies (SCTs) usually show a higher frequency of behavioral problems than typically developing (TD) children. However, little is known about the presence of behavioral issues in toddlers with SCT. This study aimed at investigating their behavioral profile in the second year of life and its impact on maternal stress.

METHOD

Participants were 87 children ranging in age from 18 to 26 months: 63 children with SCTs (all diagnosed prenatally) and 24 TD children. Their psychomotor and language development and their behavioral profile were assessed. In addition, the level of maternal parenting stress was evaluated.

RESULTS

Both psychomotor and language development were significantly lower in children with SCTs than in TD children. Conversely, no significantly greater behavioral problems emerged in children with SCTs. However, a significantly higher level of parenting stress related to a dysfunctional interaction with the child emerged in the mothers of children with SCTs. In this population, maternal stress seemed positively related to their children's emotional problems and pervasive disorders and negatively related to their children's psychomotor and linguistic competence.

CONCLUSION

Although no significant behavioral issues emerged in the second year of life, the relationships found between children's behavioral profiles and maternal parenting stress highlight the importance of prenatal counseling and support groups for parents of children with SCTs. This might help them recognize the first signs of behavioral problems and become aware of their influence on parenting stress.

Early impact of X- and Y-chromosome variations (XXX, XXY, XYY) on social communication and social emotional development in 1-2-year-old children

Sex chromosome trisomies (SCTs) are characterized by an extra X‐ or Y‐chromosome (XXX, XXY, XYY). The present study aims to investigate early signs of social communication and social emotional development in very young children with SCT. Thirty‐four children with SCT (aged 12–24 months) were included in this study, as well as 31 age‐matched controls. Social communication was measured with structured behavior observations according to the Early Social Communication Scales, and social emotional developmental level with the Bayley Social Emotional parental questionnaire. Recruitment and assessment took place in the Netherlands and in the United States. On average, 12–24‐month old children with SCT showed difficulties with early social communication, more so in responding to others as compared to initiating social communications. During social interactions, children with SCT made less frequent eye contact, compared to controls. Also, difficulties in acquiring social emotional milestones were found in 1‐year old children with SCT, with 44% of the children having social emotional vulnerabilities in the borderline or extremely low range, compared to typically developing children. In this cohort, no significant predictive effects of karyotype‐subtype (XXX, XXY, XYY) were found. Already from a very early age, SCT can be associated with increased risk for vulnerabilities in adaptive social functioning. These findings suggest that SCT impact the maturation of the social brain already from an early age, and stress the importance of early monitoring and (preventive) support early social development in young children with SCT.

[Formula: see text]A cross-sectional study of early language abilities in children with sex chromosome trisomy (XXY, XXX, XYY) aged 1-6 years

Children with sex chromosome trisomy (SCT) are at increased risk for developing language difficulties. Earlier studies have reported that as many as 70-80% of individuals with SCT show some form of language difficulties. Language develops rapidly in the first years of life; knowledge about language development at an early age is needed. The present study aims to identify the language abilities of young children with SCT across multiple language domains and to identify the percentage of children that, according to clinical guidelines, have language difficulties. Children between the ages of 1-6-years (NSCT = 103, Ncontrols = 102) were included. Nonverbal communication, early vocabulary, semantic, syntax, and phonological skills were assessed. Language difficulties were already present in 1-year-old children with SCT and across the age range in various language domains. Clinical classification showed that, depending on the assessed domain, 14.8-50.0% of the children scored below the 16th percentile. There was no effect of time of diagnosis, ascertainment bias, research site, nor SCT specific karyotype (XXX, XXY, XYY) on language outcomes. Overall, language difficulties can already be present in very young children with SCT within various language domains. These findings appear to be robust within the SCT group. These results highlight the importance of monitoring both receptive and expressive language development already at the earliest stages of nonverbal communication. Finally, as early language skills are the building blocks for later social communication, literacy, and self-expression, studies that investigate the effect of early interventions on later language outcomes are warranted.

Early Preventive Intervention for Young Children With Sex Chromosome Trisomies (XXX, XXY, XYY): Supporting Social Cognitive Development Using a Neurocognitive Training Program Targeting Facial Emotion Understanding

BACKGROUND

Sex Chromosome Trisomies (SCTs; XXX, XXY, XYY) are genetic conditions that are associated with increased risk for neurodevelopmental problems and psychopathology. There is a great need for early preventive intervention programs to optimize outcome, especially considering the increase in prenatal diagnoses due to recent advances in non-invasive prenatal screening. This study is the first to evaluate efficacy of a neurocognitive training in children with SCT. As social behavioral problems have been identified as among the key areas of vulnerability, it was targeted at improving a core aspect of social cognition, the understanding of social cues from facial expressions.

METHODS

Participants were 24 children with SCT and 18 typically developing children, aged 4-8 years old. Children with SCT were assigned to a training (n = 13) or waiting list (no-training) group (n = 11). Children in the training group completed a neurocognitive training program (The Transporters), aimed to increase understanding of facial emotions. Participants were tested before and after the training on facial emotion recognition and Theory of Mind abilities (NEPSY-II), and on social orienting (eyetracking paradigm). The SCT no-training group and typically developing control group were also assessed twice with the same time interval without any training. Feasibility of the training was evaluated with the Social Validity Questionnaire filled out by the parents and by children's ratings on a Visual Analog Scale.

RESULTS

The SCT training group improved significantly more than the SCT no-training and TD no-training group on facial emotion recognition (large effect size; η p 2 = 0.28), performing comparable to typical controls after completing the training program. There were no training effects on ToM abilities and social orienting. Both children and parents expressed satisfaction with the feasibility of the training.

CONCLUSIONS

The significant improvement in facial emotion recognition, with large effect sizes, suggests that there are opportunities for positively supporting the development of social cognition in children with an extra X- or Y-chromosome, already at a very young age. This evidence based support is of great importance given the need for preventive and early training programs in children with SCT, aimed to minimize neurodevelopmental impact.

Early developmental impact of sex chromosome trisomies on attention deficit-hyperactivity disorder symptomology in young children

Individuals with sex chromosome trisomies ([SCT], XXX, XXY, and XYY)) are at increased risk for neurodevelopmental problems, given that a significant portion of the sex chromosome genes impact brain functioning. An elevated risk for psychopathology has also been described, including attention deficit-hyperactivity disorder (ADHD). The present study aimed at identifying early markers of ADHD, providing the first investigation of ADHD symptomology in very young children with SCT. The variety, type, and severity of ADHD symptomology in 1-6-year-old children with SCT (n = 104) were compared with population-based controls (n = 101) using the strengths and weaknesses of ADHD symptoms and normal-behavior (SWAN) parent-report questionnaire. ADHD symptomology was significantly more prevalent in SCT and already present from toddlerhood on, compared to controls. ADHD inattention symptoms were significantly increased in all karyotypes (XXX, XXY, and XYY), boys with XYY also showed significantly more hyperactivity/impulsivity symptoms than controls. Inattentiveness was more pronounced with increasing age for SCT, in contrast to controls. Within the SCT group, 24% of the children had significantly elevated ADHD symptoms at a clinical level. Already from an early age on, SCT is associated with a risk for ADHD, suggesting that its neurodevelopmental risk lies anchored in early brain maturation. Studying this genetically vulnerable population allows for the prospective study of risk markers to facilitate early and preventive interventions.

Prenatal Genetic Diagnosis of a Sex Chromosome Aneuploidy: Parent Experiences

Sex chromosome aneuploidies (SCAs) occur in 1 in every 400 births. SCAs are highly variable and have uncertain prognoses, complicating the delivery of prenatal cell-free DNA (cfDNA) results or diagnosis following amniocentesis or chorionic villus sampling. Using a mixed-methods approach, we explored the experiences of parents receiving a prenatal diagnosis of a fetus with SCA. Responses to open-ended questions were qualitatively analyzed. Of the 323 parents who completed the survey, 122 received a prenatal diagnosis and answered at least one open-ended question. Most parents did not recall being informed that cfDNA screening or amniocentesis could reveal the presence of a SCA prior to testing and described feeling unprepared for a positive result. Variation was found between parents who were delivered a diagnosis by a genetic professional versus other clinical specialties. Many parents expressed that the diagnosis was delivered in a way that emphasized the negative attributes of the SCA and that they were provided limited support materials. Parents who received a prenatal diagnosis of a SCA expressed a desire for more supportive delivery of prenatal diagnosis that focuses on parental education and nuanced discussion of potential phenotypes. Genetic counselors should be aware of the range of parental experiences when receiving a SCA diagnosis from non-genetic providers. Prenatal SCA diagnoses are predicted to increase as prenatal cfDNA screening becomes more widely used. Collaborations for greater provider education and comprehensive materials on SCAs are essential to facilitate the delivery of SCA diagnoses and improve parent understanding and support.

Early neurodevelopmental and medical profile in children with sex chromosome trisomies: Background for the prospective eXtraordinarY babies study to identify early risk factors and targets for intervention

Sex chromosome trisomies (SCT), including Klinefelter syndrome/XXY, Trisomy X, and XYY syndrome, occur in 1 of every 500 births. The past decades of research have resulted in a broadening of known associated medical comorbidities as well as advances in psychological research. This review summarizes what is known about early neurodevelopmental, behavioral, and medical manifestations in young children with SCT. We focus on recent research and unanswered questions related to the risk for neurodevelopmental disorders that commonly present in the first years of life and discuss the medical and endocrine manifestations of SCT at this young age. The increasing rate of prenatal SCT diagnoses provides the opportunity to address gaps in the existing literature in a new birth cohort, leading to development of the eXtraordinarY Babies Study. This study aims to better describe and compare the natural history of SCT conditions, identify predictors of positive and negative outcomes in SCT, evaluate developmental and autism screening measures commonly used in primary care practices for the SCT population, and build a rich data set linked to a bank of biological samples for future study. Results from this study and ongoing international research efforts will inform evidence-based care and improve health and neurodevelopmental outcomes.

The behavioral profile of children aged 1-5 years with sex chromosome trisomy (47,XXX, 47,XXY, 47,XYY)

Children with SCT have an increased risk of suboptimal neurodevelopment. Previous studies have shown an elevated risk for neurobehavioral problems in individuals with SCT. However, not much is known about neurobehavioral problems in very young children; knowledge that could help with early identification of children at risk for suboptimal development, and that could help establish targets for early intervention. This study addressed the question of what the behavioral profile of children with SCT aged 1–5 years looks like. In total, 182 children aged 1–5 years participated in this study (N_SCT=87, N_{nonclinical controls} = 95). Recruitment and assessment took place in the Netherlands and the United States. The SCT group was recruited through prospective follow‐up (50%), information seeking parents (31%), and clinical referral (18%). Behavioral profiles were assessed with the child behavior checklist and the ages‐and‐stages social–emotional questionnaire.

Levels of parent‐rated problem behavior were higher in children with SCT. Difficulties with overall social–emotional functioning were already present in 1‐year‐olds, and elevated scores were persistent across the full age range. Affective and pervasive developmental behaviors were seen in late toddlerhood and prominent at preschool age. Anxiety, attention deficit, and oppositional defiant behaviors were seen in preschool‐aged children. Within this cross‐sectional study, the developmental trajectory of affective, pervasive developmental, and oppositional defiant behaviors seemed to be different for SCT children than nonclinical controls.

Collectively, these results demonstrate the importance of behavioral screening for behavioral problems in routine clinical care for children with SCT from a young age. Social–emotional problems may require special attention, as these problems seem most prominent, showing increased risk across the full age range, and with these problems occurring regardless of the timing of diagnosis, and across all three SCT karyotypes.