Just how happy is the happy puppet? An emotion signaling and kinship theory perspective on the behavioral phenotype of children with Angelman syndrome

Imprinted genes and the manipulation of parenting in mammals

Genomic imprinting refers to the parent-of-origin expression of genes, which originates from epigenetic events in the mammalian germ line. The evolution of imprinting may reflect a conflict over resource allocation early in life, with silencing of paternal genes in offspring soliciting increased maternal provision and silencing of maternal genes limiting demands on the mother. Parental caregiving has been identified as an area of potential conflict, with several imprinted genes serendipitously found to directly influence the quality of maternal care. Recent systems biology approaches, based on single-cell RNA sequencing data, support a more deliberate relationship, which is reinforced by the finding that imprinted genes expressed in the offspring influence the quality of maternal caregiving. These bidirectional, reiterative relationships between parents and their offspring are critical both for short-term survival and for lifelong wellbeing, with clear implications for human health.

Refining the Behavioral Phenotype of Angelman Syndrome: Examining Differences in Motivation for Social Contact Between Genetic Subgroups

Angelman syndrome (AS) is caused by loss of information from the 15q11.2-13 region on the maternal chromosome with striking phenotypic difference from Prader–Willi syndrome in which information is lost from the same region on the paternal chromosome. Motivation for social contact and sensory seeking behaviors are often noted as characteristics of the phenotype of AS and it has been argued that the strong drive for social contact supports a kinship theory interpretation of genomic imprinting. In this study we developed an experimental paradigm for quantifying the motivation for social contact in AS and examined differences across the genetic subtypes that cause AS [deletion, imprinting centre defect (ICD), uniparental disomy and UBE3A mutation]. Using single case experimental designs we examined the rate of acquisition of behavioral responses using operant learning paradigms for 21 children with AS whilst systematically varying the nature of social and sensory reinforcement. Variability in rates of acquisition was influenced by the nature of rewarding stimuli. Across the total sample both sensory stimuli and social contact could increase the rate of rewarded behavior with difference between children in the most effective reward. A striking difference in the rewarding properties of social contact across genetic subtypes was evidenced by non-deletion genetic causes of AS showing significantly higher rates of responding than the deletion cause in the social reinforcement paradigm. The results indicate that reinforcer assessment can beneficially inform behavioral interventions and that within syndrome variability in the behavioral phenotype of AS is likely driven by genetic difference. The non-deletion cause of AS, and particularly the ICD group, may be the optimal group for further study of genomic imprinting.

Response to vocal music in Angelman syndrome contrasts with Prader-Willi syndrome

Parent-offspring conflict-conflict over resource distribution within families due to differences in genetic relatedness-is the biological foundation for many psychological phenomena. In genomic imprinting disorders, parent-specific genetic expression is altered causing imbalances in behaviors influenced by parental investment. We use this natural experiment to test the theory that parent-offspring conflict contributed to the evolution of vocal music by moderating infant demands for parental attention. Individuals with Prader-Willi syndrome, a genomic imprinting disorder resulting from increased relative maternal genetic contribution, show enhanced relaxation responses to song, consistent with reduced demand for parental investment (Mehr et al., 2017, Psychological Science). We report the necessary complementary pattern here: individuals with Angelman syndrome, a genomic imprinting disorder resulting from increased relative paternal genetic contribution, demonstrate a relatively reduced relaxation response to song, suggesting increased demand for parental attention. These results support the extension of genetic conflict theories to psychological resources like parental attention.

Baby food and bedtime: Evidence for opposite phenotypes from different genetic and epigenetic alterations in Prader-Willi and Angelman syndromes

Prader–Willi and Angelman syndromes are often referred to as a sister pair of neurodevelopmental disorders, resulting from different genetic and epigenetic alterations to the same chromosomal region, 15q11-q13. Some of the primary phenotypes of the two syndromes have been suggested to be opposite to one another, but this hypothesis has yet to be tested comprehensively, and it remains unclear how opposite effects could be produced by changes to different genes in one syndrome compared to the other. We evaluated the evidence for opposite effects on sleep and eating phenotypes in Prader–Willi syndrome and Angelman syndrome, and developed physiological–genetic models that represent hypothesized causes of these differences. Sleep latency shows opposite deviations from controls in Prader–Willi and Angelman syndromes, with shorter latency in Prader–Willi syndrome by meta-analysis and longer latency in Angelman syndrome from previous studies. These differences can be accounted for by the effects of variable gene dosages of UBE3A and MAGEL2, interacting with clock genes, and leading to acceleration (in Prader–Willi syndrome) or deceleration (in Angelman syndrome) of circadian rhythms. Prader–Willi and Angelman syndromes also show evidence of opposite alterations in hyperphagic food selectivity, with more paternally biased subtypes of Angelman syndrome apparently involving increased preference for complementary foods (“baby foods”); hedonic reward from eating may also be increased in Angelman syndrome and decreased in Prader–Willi syndrome. These differences can be explained in part under a model whereby hyperphagia and food selectivity are mediated by the effects of the genes SNORD-116, UBE3A and MAGEL2, with outcomes depending upon the genotypic cause of Angelman syndrome. The diametric variation observed in sleep and eating phenotypes in Prader–Willi and Angelman syndromes is consistent with predictions from the kinship theory of imprinting, reflecting extremes of higher resource demand in Angelman syndrome and lower demand in Prader–Willi syndrome, with a special emphasis on social–attentional demands and attachment associated with bedtime, and feeding demands associated with mother-provided complementary foods compared to offspring-foraged family-type foods.

The nature of social preference and interactions in Smith-Magenis syndrome

This natural observation study was designed to evaluate hypothesized elevated 'attention-seeking' and preference for adult attention in Smith-Magenis syndrome. Ten children with Smith-Magenis syndrome were observed across one school day, together with an age matched sample of 10 children with Down syndrome. Levels of attention given to, and vigilance for, adults and peers were recorded and compared. Sequences of behaviour were analyzed to evaluate the temporal relationships between giving and receiving attention during adult-child interactions. Compared to children with Down syndrome, children with Smith-Magenis syndrome gave preferential attention to adults and looked towards adults significantly more than they looked towards peers. Sequential analyses revealed that while children with Smith-Magenis syndrome did not initiate interactions with adults more than children with Down syndrome did, reciprocity between child and adult social behaviours in Smith-Magenis syndrome within interactions was compromised. This less synchronous sequence of child and adult interactions in Smith-Magenis syndrome may be the result of children with Smith-Magenis syndrome attempting to initiate interaction at times when it is unavailable. The marked preference for interacting with adults over peers in Smith-Magenis syndrome indicates atypicality of social interaction in this syndrome.

The imprinted brain: how genes set the balance between autism and psychosis

The imprinted brain theory proposes that autism spectrum disorder (ASD) represents a paternal bias in the expression of imprinted genes. This is reflected in a preference for mechanistic cognition and in the corresponding mentalistic deficits symptomatic of ASD. Psychotic spectrum disorder (PSD) would correspondingly result from an imbalance in favor of maternal and/or X-chromosome gene expression. If differences in gene expression were reflected locally in the human brain as mouse models and other evidence suggests they are, ASD would represent not so much an 'extreme male brain' as an extreme paternal one, with PSD correspondingly representing an extreme maternal brain. To the extent that copy number variation resembles imprinting and aneuploidy in nullifying or multiplying the expression of particular genes, it has been found to conform to the diametric model of mental illness peculiar to the imprinted brain theory. The fact that nongenetic factors such as nutrition in pregnancy can mimic and/or interact with imprinted gene expression suggests that the theory might even be able to explain the notable effect of maternal starvation on the risk of PSD - not to mention the 'autism epidemic' of modern affluent societies. Finally, the theory suggests that normality represents balanced cognition, and that genius is an extraordinary extension of cognitive configuration in both mentalistic and mechanistic directions. Were it to be proven correct, the imprinted brain theory would represent one of the biggest single advances in our understanding of the mind and of mental illness that has ever taken place, and would revolutionize psychiatric diagnosis, prevention and treatment - not to mention our understanding of epigenomics.

Gender and ethnic differences in colorectal cancer screening embarrassment and physician gender preferences

PURPOSE/OBJECTIVES

To examine colorectal cancer (CRC) screening embarrassment among men and women from three ethnic groups and the associated physician gender preference by patient gender and ethnicity.

DESIGN

Cross-sectional, purposive sampling.

SETTING

Urban community in Brooklyn, NY.

SAMPLE

A purpose-derived, convenience sample of 245 European American, African American, and immigrant Jamaican men and women (aged 45-70 years) living in Brooklyn, NY.

METHODS

Participants provided demographics and completed a comprehensive measure of CRC screening embarrassment.

MAIN RESEARCH VARIABLES

Participant gender and ethnicity, physician gender, and CRC screening embarrassment regarding feces or the rectum and unwanted physical intimacy.

FINDINGS

As predicted, men and women both reported reduced fecal and rectal embarrassment and intimacy concern regarding same-gender physicians. As expected, Jamaicans reported greater embarrassment regarding feces or the rectum compared to European Americans and African Americans; however, in contrast to expectations, women reported less embarrassment than men. Interactions indicated that rectal and fecal embarrassment was particularly high among Jamaican men.

CONCLUSIONS

Men and women have a preference for same-gender physicians, and embarrassment regarding feces and the rectum shows the most consistent ethnic and gender variation.

IMPLICATIONS FOR NURSING

Discussing embarrassment and its causes, as well as providing an opportunity to choose a same-gender physician, may be promising strategies to reduce or manage embarrassment and increase CRC screening attendance.

Genomic imprinting and the evolutionary psychology of human kinship

Genomic imprinting is predicted to influence behaviors that affect individuals to whom an actor has different degrees of matrilineal and patrilineal kinship (asymmetric kin). Effects of imprinted genes are not predicted in interactions with nonrelatives or with individuals who are equally related to the actor's maternally and paternally derived genes (unless a gene also has pleiotropic effects on fitness of asymmetric kin). Long-term mating bonds are common in most human populations, but dissolution of marriage has always affected a significant proportion of mated pairs. Children born in a new union are asymmetric kin of children born in a previous union. Therefore, the innate dispositions of children toward parents and sibs are expected to be sensitive to cues of marital stability, and these dispositions may be subject to effects of imprinted genes.

Age related change in social behavior in children with Angelman syndrome

We investigated the relationship between age and laughing and smiling in children with Angelman syndrome. Twenty-four children with Angelman syndrome were exposed to three experimentally manipulated conditions: proximity only, restricted social interaction, and social interaction. Children smiled the most in the social interaction condition and the least in the proximity only condition confirming the effect of social interaction on these behaviors. There was a decline in smiling and laughing in the oldest group (13.4-15.9 years) only in the social interaction condition. This trajectory of a decline in resource soliciting behaviors with age is consistent with predictions based on kinship theory.

The Affective Paradox

Despite generally more challenging developmental, environmental, economic, health, and social contexts, minority populations in the United States often report a lower frequency of many negative affects. In some views, such findings reflect a reporting or response bias among minority groups. However, an alternate view suggests that reports of negative emotion differ because minorities do not consciously experience certain discrete emotions as frequently. A study of 1,364 women from six ethnic subpopulations tested this thesis using trait anger as an exemplar. As expected, linear regressions demonstrated that while social desirability explained some ethnic variance in anger reports, a measure of repressive coping explained additional variance in trait anger and eliminated ethnic effects; social desirability no longer predicted trait anger once repressive coping was controlled. Results are discussed in terms how of how developmentally oriented, emotion regulation theories may supplement reporting bias conceptualizations of affective differences across ethnic groups. Implications and directions for future research are given.

Phenotype-environment interactions in genetic syndromes associated with severe or profound intellectual disability

The research literature notes both biological and operant theories of behavior disorder in individuals with intellectual disabilities. These two theories of genetic predisposition and operant reinforcement remain quite distinct; neither theory on its own is sufficient to explain challenging behavior in genetic syndromes and an integrated approach is required. This literature review integrates the two approaches by exploring how environmental factors can influence problem behavior in genetic syndromes associated with intellectual disability. Particular attention is paid to studies that describe evidence that problem behaviors in syndromes that are considered to be phenotypic are associated with other aspects of an established behavioral phenotype. The review highlights how the study of phenotype-environment interactions within syndromes can promote understanding of the aetiology of problem behaviors both within genetic syndromes and, ultimately, the wider population of individuals with severe intellectual disabilities. The review also evaluates the current status of research and the methods typically employed. Implications for intervention, future research and extending existing causal models of challenging behavior are discussed.

The expression and assessment of emotions and internal states in individuals with severe or profound intellectual disabilities

The expression of emotions and internal states by individuals with severe or profound intellectual disabilities is a comparatively under-researched area. Comprehensive or standardized methods of assessing or understanding the emotions and internal states within this population, whose ability to communicate is significantly compromised, do not exist. The literature base will be discussed and compared to that applicable to the general population. Methods of assessing broader internal states, notably depression, anxiety, and pain within severe or profound intellectual disabilities are also addressed. Finally, this review will examine methods of assessing internal states within genetic syndromes, including hunger, social anxiety, and happiness within Prader-Willi, Fragile-X and Angelman syndrome. This will allow for identification of robust methodologies used in assessing the expression of these internal states, some of which may be useful when considering how to assess emotions within individuals with intellectual disabilities.

The evolution of autistic-like and schizotypal traits: a sexual selection hypothesis

In this paper we present a new hypothesis on the evolution of autistic-like and schizotypal personality traits. We argue that autistic-like and schizotypal traits contribute in opposite ways to individual differences in reproductive and mating strategies, and have been maintained - at least in part - by sexual selection through mate choice. Whereas positive schizotypy can be seen as a psychological phenotype oriented to high-mating effort and good genes displays in both sexes, autistic-like traits in their non-pathological form contribute to a male-typical strategy geared toward high parental investment, low-mating effort, and long-term resource allocation. At the evolutionary-genetic level, this sexual selection hypothesis is consistent with Crespi and Badcock's "imprinted brain" theory of autism and psychosis; the effect of offspring mating behavior on resource flow within the family connects sexual selection with genomic imprinting in the context of human biparental care. We conclude by presenting the results of an empirical study testing one of the predictions derived from our hypothesis. In a sample of 199 college students, autistic-like traits predicted lower interest in short-term mating, higher partner-specific investment, and stronger commitment to long-term romantic relations, whereas positive schizotypy showed the opposite pattern of effects.

Gender moderates the associations between attachment and discrete emotions in late middle age and later life

OBJECTIVES

Although patterns of attachment have been linked to patterns of emotional experience, studies in developmentally diverse samples are few and have not yet examined possible gender differences in attachment or their implications for emotional wellbeing. This article describes patterns of attachment in a diverse sample of 616 men and women from middle age and later life, examines the relations between attachment and nine discrete emotions, and tests the thesis that gender moderates these associations.

METHODS

Convenience sampling was used to derive a sample of 616 ethnically diverse men and women from seven ethnic groups.

RESULTS

Multiple regressions controlling for demographics found no gender differences in attachment categorizations although men reported greater dimensional fearful avoidance. Security predicted greater joy and interest whereas dismissingness was associated with lower shame and fear and with greater interest. Both preoccupation and fearful avoidance predicted most negative emotions but were not associated with positive emotions. Finally, gender moderated these associations such that (a) attachment security was more closely related to interest and, marginally, joy, among men; (b) fearful avoidance was more closely related to fear and contempt among men; and (c) preoccupation was associated with greater interest among men, whereas fear and contempt were associated with preoccupation among women only.

CONCLUSION

Interpreted in the context of theories of emotions, the social origins of emotional experience, and the different roles that social relationships have for aging men and women, our data imply that attachment styles may differentially predict male emotions because of their less diverse networks.

Experimental functional analysis of aggression in children with Angelman syndrome

BACKGROUND

Kinship theory suggests that genomic imprinting could account for phenotypic behaviors that increase (in the case of Angelman syndrome) or decrease (for Prader-Willi syndrome) the drive to access social resources (adult contact) depending on the imprinting parent-of-origin. Difficult to manage behaviors, such as aggression that is common in Angelman syndrome, could serve the function of increasing social interaction. We hypothesise that the commonly reported aggressive behavior in children with Angelman syndrome will be attention maintained.

METHODS

Experimental functional analysis was carried out with twelve children with Angelman syndrome caused by either a deletion (n=10) or uniparental disomy (n=2). The relative increase and decrease of aggressive behaviors was observed in response to experimentally manipulated levels of adult attention and demand. Laughing and smiling, crying and frowning, and physical initiation with an adult were also measured.

RESULTS

Aggression was seen in ten of the twelve children. One child evidenced a pattern of aggression across conditions consistent with maintenance by attention, three children showed higher levels of aggression during social interaction and two children showed escape motivated aggression.

DISCUSSION

With the exception of one child the results did not confirm the hypothesis. However, the pattern of increased aggression in the high social contact condition combined with evidence of positive affect during this condition suggests aggression may serve to both maintain and initiate social contact and this interpretation is consistent with previous research. The negative results may also have been influenced by the age of the children and the low levels of observed aggression.

Genomic imprinting and disorders of the social brain; shades of grey rather than black and white

Crespi & Badcock (C&B) provide a novel hypothesis outlining a role for imprinted genes in mediating brain functions underlying social behaviours. The basic premise is that maternally expressed genes are predicted to promote hypermentalistic behaviours, and paternally expressed genes hypomentalistic behaviours. The authors provide a detailed overview of data supporting their ideas, but as we discuss, caution should be applied in interpreting these data.

Is this conjectural phenotypic dichotomy a plausible outcome of genomic imprinting?

What is the status of the dichotomy proposed and the nosological validity of the contrasting pathologies described in the target article? How plausibly can dysregulated imprinting explain the array of features described, compared with other genetic models? We believe that considering alternative models is more likely to lead in the long term to the correct classification and explanation of the component behaviours.

Dental treatment of children with Angelman syndrome: a case report

Angelman syndrome (AS) is a rare genetic neurological disorder. The main clinical characteristics of this syndrome are delayed neuropsychological development, intellectual disability, speech impairment, movement or balance disorder, and a behavioural uniqueness. The syndrome has oral manifestations such as diastemas, tongue thrusting, sucking/swallowing disorder, mandibular prognathism, a wide mouth, frequent drooling, and excessive chewing behaviour. The dental literature on the syndrome is scarce. The purpose of paper is to describe the interesting aspects of the dental treatment of a child with AS.

Construction and evolution of imprinted loci in mammals

Genomic imprinting first evolved in mammals around the time that humans last shared a common ancestor with marsupials and monotremes (180-210 million years ago). Recent comparisons of large imprinted domains in these divergent mammalian groups have shown that imprinting evolved haphazardly at various times in different lineages, perhaps driven by different selective forces. Surprisingly, some imprinted domains were formed relatively recently, using non-imprinted components acquired from unexpected genomic regions. Rearrangement and the insertion of retrogenes, small nucleolar RNAs, microRNAs, differential CpG methylation and control by non-coding RNA often accompanied the acquisition of imprinting. Here, we use comparisons between different mammalian groups to chart the course of evolution of two related epigenetic regulatory systems in mammals: genomic imprinting and X-chromosome inactivation.

Genomic imprinting and the expression of affect in Angelman syndrome: what's in the smile?

BACKGROUND

Kinship theory (or the genomic conflict hypothesis) proposes that the phenotypic effects of genomic imprinting arise from conflict between paternally and maternally inherited alleles. A prediction arising for social behaviour from this theory is that imbalance in this conflict resulting from a deletion of a maternally imprinted gene, as in Angelman syndrome (AS), will result in a behavioural phenotype that should evidence behaviours that increase access to maternally provided social resources (adult contact).

METHOD

Observation of the social behaviour of children with AS (n = 13), caused by a deletion at 15q11-q13, and a matched comparison group (n = 10) was undertaken for four hours in a socially competitive setting and the effect of adult attention on child behaviours and the effect of child smiling on adult behaviours evaluated using group comparisons and observational lag sequential analyses.

RESULTS

The AS group smiled more than the comparison group in all settings, which had different levels of adult attention, and more when the level of adult attention was high. Smiling by children with AS evoked higher levels of adult attention, eye contact and smiling both than by chance and in comparison to other children and this effect was sustained for 30 s to 50 s. Smiling by children with AS was frequently preceded by child initiated contact toward the adult.

DISCUSSION

The results are consistent with a kinship theory explanation of the function of heightened levels of sociability and smiling in Angelman syndrome and provide support for an emotion signalling interpretation of the mechanism by which smiling accesses social resources. Further research on other behaviours characteristic of Angelman and Prader-Willi syndromes warrant examination from this perspective.

Genomic imprinting and the social brain

Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted genes, that in some cases results in monoallelic expression from one parental allele. Genomic imprinting is often thought to have evolved as a consequence of the intragenomic conflict between the parental alleles that occurs whenever there is an asymmetry of relatedness. The two main examples of asymmetry of relatedness are when there is partiality of parental investment in offspring (as is the case for placental mammals, where there is also the possibility of extended postnatal care by one parent), and in social groups where there is a sex-biased dispersal. From this evolutionary starting point, it is predicted that, at the behavioural level, imprinted genes will influence what can broadly be termed bonding and social behaviour. We examine the animal and human literature for examples of imprinted genes mediating these behaviours, and divide them into two general classes. Firstly, mother-offspring interactions (suckling, attachment and maternal behaviours) that are predicted to occur when partiality in parental investment in early postnatal offspring occurs; and secondly, adult social interactions, when there is an asymmetry of relatedness in social groups. Finally, we return to the evolutionary theory and examine whether there is a pattern of behavioural functions mediated by imprinted genes emerging from the limited data, and also whether any tangible predictions can be made with regards to the direction of action of genes of maternal or paternal origin.

Modes of imprinted gene action in learning disability

BACKGROUND

It is now widely acknowledged that there may be a genetic contribution to learning disability and neuropsychiatric disorders, stemming from evidence provided by family, twin and adoption studies, and from explicit syndromic conditions. Recently it has been recognized that in some cases the presentation of genetic syndromes (or discrete aspects of disorders) is dependent on the sex of the transmitting parent. Such 'parent-of-origin effects' can be explained by a number of genetic mechanisms, a predominant one of which is genomic imprinting. Genomic imprinting refers to the parent of origin-specific epigenetic marking of an allele of a gene, such that for some genes it is mainly the maternally inherited allele only that is expressed, whereas for others expression occurs mainly from the paternal copy.

METHODS

Here we discuss the contribution of imprinted genes to mental dysfunction and learning disability, using clinical examples of association studies and explicit imprinting disorders (with particular emphasis to Angelman and Prader-Willi syndromes), and evidence from animal work.

RESULTS

Clinical and animal studies strongly suggest that imprinted genes contribute to brain functioning, and when the genes or epigenetic processes are disrupted, this can give rise to neuropsychiatric problems. Another system to which imprinted genes provide a large contribute is the placenta and foetal development. Epidemiological studies suggest that this is also a key area in which dysregulation can give rise to learning difficulties.

CONCLUSIONS

Disruption of imprinted genes, or the epigenetic processes controlling them, can contribute to learning disability. These effects can be divided into two types: direct effects, such as those seen in explicit imprinting disorders such as Angelman and Prader-Willi syndromes, and indirect effects as manifest via changes in foetal programming.

Imprinted genes and mother-offspring interactions

A subset of mammalian genes is subject to genomic imprinting. These imprinted genes show parent of origin specific monoallelic or parental allele-biased expression, such that for some genes, it is mainly the maternally inherited allele that is expressed, whereas for others, expression occurs mainly from the paternal copy. Evolutionary theory predicts that these genes will have a role in the mother-offspring interaction in mammals, and indeed many imprinted genes have a role in growth and placental function, and consequently influence prenatal development. In addition to the developing foetus, there is increasing evidence to suggest that imprinted genes influence the pre-weaning mother-offspring relationship, and consequently the development of the offspring into adulthood. In this review, we present an overview of the role imprinted genes play in the mother-offspring relationship using examples from the human and animal literature.