X- vs. Y-Chromosome Influences on Human Behavior: A Deep Phenotypic Comparison of Psychopathology in XXY and XYY Syndromes.

Do different genetic disorders impart different psychiatric risk profiles? This question has major implications for biological and translational aspects of psychiatry, but has been difficult to tackle given limited access to shared batteries of fine-grained clinical data across genetic disorders. Using a new suite of generalizable analytic approaches, we examine gold-standard diagnostic ratings, scores on 66 dimensional measures of psychopathology, and measures of cognition and functioning in two different sex chromosome aneuploidies (SCAs) - Klinefelter (XXY/KS) and XYY syndrome (n=102 and 64 vs. n=74 and 60 matched XY controls, total n=300). We focus on SCAs for their high collective prevalence, informativeness regarding differential X- vs. Y-chromosome effects, and potential relevance for normative sex differences. We show that XXY/KS elevates rates for most psychiatric diagnoses as previously reported for XYY, but disproportionately so for anxiety disorders. Fine-mapping across all 66 traits provides a detailed profile of psychopathology in XXY/KS which is strongly correlated with that of XYY (r=.75 across traits) and robust to ascertainment biases, but reveals: (i) a greater penetrance of XYY than KS/XXY for most traits except mood/anxiety problems, and (ii) a disproportionate impact of XYY vs. XXY/KS on social problems. XXY/KS and XXY showed a similar coupling of psychopathology with adaptive function and caregiver strain, but not IQ. This work provides new tools for deep-phenotypic comparisons of genetic disorders in psychiatry and uses these to detail unique and shared effects of the X- and Y-chromosome on human behavior.

Deep phenotypic analysis of psychiatric features in genetically defined cohorts: application to XYY syndrome.

BACKGROUND: Recurrent gene dosage disorders impart substantial risk for psychopathology. Yet, understanding that risk is hampered by complex presentations that challenge classical diagnostic systems. Here, we present a suite of generalizable analytic approaches for parsing this clinical complexity, which we illustrate through application to XYY syndrome. METHOD: We gathered high-dimensional measures of psychopathology in 64 XYY individuals and 60 XY controls, plus additional interviewer-based diagnostic data in the XYY group. We provide the first comprehensive diagnostic description of psychiatric morbidity in XYY syndrome and show how diagnostic morbidity relates to functioning, subthreshold symptoms, and ascertainment bias. We then map behavioral vulnerabilities and resilience across 67 behavioral dimensions before borrowing techniques from network science to resolve the mesoscale architecture of these dimensions and links to observable functional outcomes. RESULTS: Carriage of an extra Y-chromosome increases risk for diverse psychiatric diagnoses, with clinically impactful subthreshold symptomatology. Highest rates are seen for neurodevelopmental and affective disorders. A lower bound of < 25% of carriers are free of any diagnosis. Dimensional analysis of 67 scales details the profile of psychopathology in XYY, which survives control for ascertainment bias, specifies attentional and social domains as the most impacted, and refutes stigmatizing historical associations between XYY and violence. Network modeling compresses all measured symptom scales into 8 modules with dissociable links to cognitive ability, adaptive function, and caregiver strain. Hub modules offer efficient proxies for the full symptom network. CONCLUSIONS: This study parses the complex behavioral phenotype of XYY syndrome by applying new and generalizable analytic approaches for analysis of deep-phenotypic psychiatric data in neurogenetic disorders.

Modeling familial predictors of proband outcomes in neurogenetic disorders: initial application in XYY syndrome.

BACKGROUND: Disorders of gene dosage can significantly increase risk for psychopathology, but outcomes vary greatly amongst carriers of any given chromosomal aneuploidy or sub-chromosomal copy number variation (CNV). One potential path to advance precision medicine for neurogenetic disorders is modeling penetrance in probands relative to observed phenotypes in their non-carrier relatives. Here, we seek to advance this general analytic framework by developing new methods in application to XYY syndrome-a sex chromosome aneuploidy that is known to increase risk for psychopathology. METHODS: We analyzed a range of cognitive and behavioral domains in XYY probands and their non-carrier family members (n = 58 families), including general cognitive ability (FSIQ), as well as continuous measures of traits related to autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). Proband and relative scores were compared using covariance, regression and cluster analysis. Comparisons were made both within and across traits. RESULTS: Proband scores were shifted away from family scores with effect sizes varying between 0.9 and 2.4 across traits. Only FSIQ and vocabulary scores showed a significant positive correlation between probands and their non-carrier relatives across families (R2 ~ 0.4). Variability in family FSIQ also cross-predicted variability in proband ASD trait severity. Cluster analysis across all trait-relative pairings revealed that variability in parental psychopathology was more weakly coupled to their XYY versus their euploid offspring. CONCLUSIONS: We present a suite of generalizable methods for modeling variable penetrance in aneuploidy and CNV carriers using family data. These methods update estimates of phenotypic penetrance for XYY and suggest that the predictive utility of family data is likely to vary for different traits and different gene dosage disorders. TRIAL REGISTRATIONS: ClinicalTrials.gov NCT00001246 , "89-M-0006: Brain Imaging of Childhood Onset Psychiatric Disorders, Endocrine Disorders and Healthy Controls." Date of registry: 01 October 1989.

Altered Sex Chromosome Dosage Induces Coordinated Shifts in Cortical Anatomy and Anatomical Covariance.

Sex chromosome dosage (SCD) variation increases risk for neuropsychiatric impairment, which may reflect direct SCD effects on brain organization. Here, we 1) map cumulative X- and Y-chromosome dosage effects on regional cortical thickness (CT) and investigate potential functional implications of these effects using Neurosynth, 2) test if this map is organized by patterns of CT covariance that are evident in health, and 3) characterize SCD effects on CT covariance itself. We modeled SCD effects on CT and CT covariance for 308 equally sized regions of the cortical sheet using structural neuroimaging data from 301 individuals with varying numbers of sex chromosomes (169 euploid, 132 aneuploid). Mounting SCD increased CT in the rostral frontal cortex and decreased CT in the lateral temporal cortex, bilaterally. Regions targeted by SCD were associated with social functioning, language processing, and comprehension. Cortical regions with a similar degree of SCD-sensitivity showed heightened CT covariance in health. Finally, greater SCD also increased covariance among regions similarly affected by SCD. Our study both 1) develops novel methods for comparing typical and disease-related structural covariance networks in the brain and 2) uses these techniques to resolve and identify organizing principles for SCD effects on regional cortical anatomy and anatomical covariance.

Characterization of autism spectrum disorder and neurodevelopmental profiles in youth with XYY syndrome.

BACKGROUND: XYY syndrome is a sex chromosome aneuploidy that occurs in ~ 1/850 male births and is associated with increased risk for neurodevelopmental difficulties. However, the profile of neurodevelopmental impairments, including symptoms of autism spectrum disorder (ASD) in XYY remains poorly understood. This gap in knowledge has persisted in part due to lack of access to patient cohorts with dense and homogeneous phenotypic data. METHODS: We evaluated a single-center cohort of 64 individuals with XYY aged 5-25 years, using a standardized battery of cognitive and behavioral assessments spanning developmental milestones, IQ, adaptive behavior, academic achievement, behavioral problems, and gold-standard diagnostic instruments for ASD. Our goals were to (i) detail the neurodevelopmental profile of XYY with a focus on ASD diagnostic rates and symptom profiles, (ii) screen phenotypes for potential ascertainment bias effects by contrasting pre- vs. postnatally diagnosed XYY subgroups, and (iii) define major modules of phenotypic variation using graph-theoretical analysis. RESULTS: Although there was marked inter-individual variability, the average profile was characterized by some degree of developmental delay, and decreased IQ and adaptive behavior. Impairments were most pronounced for language and socio-communicative functioning. The rate of ASD was 14%, and these individuals exhibited autism symptom profiles resembling those observed in ASD without XYY. Most neurodevelopmental dimensions showed milder impairment among pre- vs. postnatally diagnosed individuals, with clinically meaningful differences in verbal IQ. Feature network analysis revealed three reliably separable modules comprising (i) cognition and academic achievement, (ii) broad domain psychopathology and adaptive behavior, and (iii) ASD-related features. CONCLUSIONS: By adding granularity to our understanding of neurodevelopmental difficulties in XYY, these findings assist targeted clinical assessment of newly identified cases, motivate greater provision of specialized multidisciplinary support, and inform future efforts to integrate behavioral phenotypes in XYY with neurobiology. TRIAL REGISTRATIONS: ClinicalTrials.gov NCT00001246 , "89-M-0006: Brain Imaging of Childhood Onset Psychiatric Disorders, Endocrine Disorders and Healthy Controls."

Antibody to the gp120 V1/V2 loops and CD4+ and CD8+ T cell responses in protection from SIVmac251 vaginal acquisition and persistent viremia.

The human papillomavirus pseudovirions (HPV-PsVs) approach is an effective gene-delivery system that can prime or boost an immune response in the vaginal tract of nonhuman primates and mice. Intravaginal vaccination with HPV-PsVs expressing SIV genes, combined with an i.m. gp120 protein injection, induced humoral and cellular SIV-specific responses in macaques. Priming systemic immune responses with i.m. immunization with ALVAC-SIV vaccines, followed by intravaginal HPV-PsV-SIV/gp120 boosting, expanded and/or recruited T cells in the female genital tract. Using a stringent repeated low-dose intravaginal challenge with the highly pathogenic SIVmac251, we show that although these regimens did not demonstrate significant protection from virus acquisition, they provided control of viremia in a number of animals. High-avidity Ab responses to the envelope gp120 V1/V2 region correlated with delayed SIVmac251 acquisition, whereas virus levels in mucosal tissues were inversely correlated with antienvelope CD4(+) T cell responses. CD8(+) T cell depletion in animals with controlled viremia caused an increase in tissue virus load in some animals, suggesting a role for CD8(+) T cells in virus control. This study highlights the importance of CD8(+) cells and antienvelope CD4(+) T cells in curtailing virus replication and antienvelope V1/V2 Abs in preventing SIVmac251 acquisition.