The 2D:4D digit ratio is commonly used as a surrogate possibly reflecting prenatal testosterone levels. Indirect evidence comes from studies investigating the association between 2D:4D and human characteristics that likely relate to prenatal testosterone. In children, sex-typed play reveals large sex differences early in development and an influence of prenatal testosterone is likely. Findings on the association between 2D:4D and children\'s sex-typed play are heterogeneous and other influences on the development of sex-typed play have been suggested, most of all social influences like siblings, their sex and birth order. The current study examined the association between right and left 2D:4D, a proposed surrogate for prenatal testosterone exposure, which was assessed in right and left hands of N = 505 6-month-old children, and sex-typed play behavior, which was evaluated 3.5 years later using the Pre-School Activities Inventory (PSAI), and the influence of siblings. To capture differential effects of siblings\' sex and birth order, dummy-coded variables were used reflecting having no siblings as well as older or younger sisters or brothers. Multiple regression models were used to investigate the association between PSAI scores and sex, right and left 2D:4D, being a singleton as well as having an older or younger sister or brother. It was shown that sex and having an older brother were significant predictors for sex-typed play. Effects were further disentangled by conducting separate regression analyses in boys and girls. In boys, a significant association between PSAI scores and having an older brother was revealed, in girls, no significant associations were found. Results are discussed highlighting the non-significant association between 2D:4D and children\'s sex-typed play, which weakens the applicability of 2D:4D as a surrogate reflecting influences of prenatal T. Further, the importance of social factors like siblings on children\'s sex-typed play is discussed.

BACKGROUND: Typically-developing siblings of individuals with Down Syndrome often experience complex emotions towards their sibling. This study explored how social support, personal resources (optimism, sense of coherence [SOC]), and individual variables (sex, religious affiliation, siblings\' functionality) may impact emerging adult siblings\' emotions toward their sibling with Down Syndrome.
METHODS: Participants were 292 siblings of individuals with DS ranging in age from 18-27 (M=21.54, SD=2.50). Participants completed self-report questionnaires exploring optimism, SOC, support, and acceptance.
RESULTS: Higher levels of support and optimism were positively associated with positive emotions, and higher SOC with lower levels of negative emotions. Siblings\' functionality and religious affiliation interacted with variables to predict emotions.
CONCLUSIONS: This study contributes to a greater understanding of how emotions may play a role in sibling relations during the emerging adulthood stage. It also provides unique insight into how religious affiliation may be associated with more positive outcomes for siblings.

This study investigates the direct and indirect effects of maternal and sibling relational intimacy on adolescents\' volunteering behaviors via their social responsibility values. Participants included two adolescents (50% female; M age = 14 years) and one parent (85% female; M age = 45 years) from 682 families (N = 2,046) from an ongoing longitudinal study. Adolescents self-reported their intimacy with mothers and siblings (Time 1), social responsibility values (Time 1), and volunteering (Times 1 and 2); parents reported on sociodemographic characteristics (i.e., gender, birth order, family income). Results from a structural equation model indicated that after accounting for adolescents\' earlier volunteering, both maternal and sibling intimacy were indirectly related to greater volunteering via social responsibility values. There were no significant direct effects from maternal or sibling intimacy to adolescents\' volunteering. Results indicate that both mothers and siblings are important in socializing prosocial and civic values and behaviors during adolescence.

Families of children with intellectual and developmental disabilities often face unique challenges that significantly impact their quality of life. Understanding the predictors of family quality of life (FQOL) is crucial for developing effective support systems and interventions.
OBJECTIVE: This study investigated the predictors that might influence the perception of families having a member with a disability regarding their quality of life (FQOL).
METHODS: The sample consisted of 320 family members from the Riyadh region of Saudi Arabia.
RESULTS: The overall results showed that participants\' satisfaction with FQOL was at a moderate level. Further results indicated that variables associated with severity, type of disability, and the mother\'s age and education were significant predictors of the FQOL.
CONCLUSIONS: These results emphasize the importance of considering the variables that impact FQOL, such as the severity and type of disability, and mother\'s related variables, when directing support to families with a member with a disability. The recommendations and limitations of the study were discussed.

BACKGROUND: While the literature has highlighted the immense challenges in caring for family members, it is still unclear what the needs of family carers of persons with intellectual disability and challenging behaviours are and what has worked for them. This study aims to examine 60 parents\' and siblings\' experiences in managing the challenging behaviours of their adult family member with intellectual disability whilst living at home.
METHODS: A qualitative grounded theory approach using semi-structured interviews will be adopted. Purposive sampling will be used to recruit family carers who live with adult persons with intellectual disability and use one community service in Hong Kong. Three special schools for persons with intellectual disability from northern China will be approached.
RESULTS: This study will aim to provide an in-depth understanding of the experiences of family carers and compare the different circumstances they face when managing the challenging behaviours of their adult relatives with intellectual disability in their family home.
CONCLUSIONS: Although this study targets adults with intellectual disability, the findings will provide a point of reference for adolescents and younger persons who exhibit demanding and challenging behaviours and live with their families. Recommendations can guide the development of appropriate strategies to strengthen services for family carers.

UNASSIGNED: This study investigates how social categories work and intersect in siblings bereaved by drug-related deaths\' (DRDs) stories about their relationships to their deceased brother or sister. The sociocultural embedded process of making meaning of the relationship with the deceased individual is essential in adapting to the loss. However, insight into such experiences of siblings bereaved by a DRD is scarce. Previous research has suggested that DRDs may be stigmatized life experiences for bereaved family members, and this paper furthers understanding of the experiences and issues involved in losing a sibling in a stigmatized death.
UNASSIGNED: An intersectional analysis is applied to interviews with 14 bereaved siblings. By investigating and displaying how different categories intertwine, various positionings are identified.
UNASSIGNED: Categorization of the deceased siblings as \"addicts\" constructs a troubled position. However, when \"addict\" intersects with the categories \"unique,\" \"sibling,\" and \"uncle,\" the troubled subject\'s position as an \"addict\" can be concealed.
UNASSIGNED: Normative conceptions of addiction and DRDs produce troubled subject positions. By intermingling the category of \"addict\" with other categories, less problematic positions are created. Still, intersections of categories can also construct further complexities of remorse and self-blame for the bereaved siblings.

OBJECTIVE: This prebirth cohort study examined the relationship between breastfeeding duration and behavioral problems in five-year-old Japanese children.
METHODS: Study subjects were 1198 mother-child pairs. Data were collected using a self-administered questionnaire. Emotional, conduct, hyperactivity, and peer problems and low prosocial behavior were assessed using the Strengths and Difficulties Questionnaire (SDQ).
RESULTS: Neither exclusive breastfeeding duration nor breastfeeding duration regardless of exclusivity was significantly associated with childhood emotional, conduct, hyperactivity, or peer problems or low prosocial behavior. In children with older siblings only, ≥ 4 months of exclusive breastfeeding was significantly inversely associated with hyperactivity problems (adjusted odds ratio [OR] = 0.57, 95 % confidence interval [CI]: 0.31-0.99). In children without older siblings, ≥ 4 months of exclusive breastfeeding was inversely significantly associated with low prosocial behavior (adjusted OR = 0.54, 95 % CI: 0.30-0.93). No interactions were observed between exclusive breastfeeding duration and the presence of older siblings regarding the two outcomes.
CONCLUSIONS: No associations were found between breastfeeding duration and any of the outcomes based on the SDQ. Exclusive breastfeeding for ≥ 4 months may be inversely associated with hyperactivity problems in children with older siblings and with low prosocial behavior in children without older siblings.

BACKGROUND: The rise in prevalence of atopic dermatitis has been correlated with numerous elements of the exposome, modern-day lifestyle, and familial history. The combined analysis of familial history and other risk elements may allow us to understand the driving factors behind the development of atopic dermatitis.
OBJECTIVE: We aimed to develop prediction models to assess the risk of developing atopic dermatitis using a large and diverse cohort (N=77,525) and easily-assessed risk factors.
METHODS: We analyzed electronic medical record data from Leumit Health System. Documented predictive factors include sex, season of birth, environment (urban/rural), socio-economic status, household smoking, diagnosed skin conditions, number of siblings, a paternal, maternal or sibling history of an atopic condition, and antibiotic prescriptions during pregnancy or following birth. Predictive models were trained and validated on the dataset.
RESULTS: Medium (OR 2.04, CI 1.92-2.17, p<0.001) and high (OR 2.13, CI 1.95-2.34, p<0.001) socioeconomic status, a previous diagnosis of contact dermatitis (OR 2.57, CI 2.37-2.78, p<0.001), presence of siblings with an AD diagnosis (OR 2.21, CI 2.04-2.40, p<0.001) and the percentage of siblings with any atopic condition (OR 2.58, CI 2.09-3.17, p<0.001) drove risk for AD in a logistic regression model. A random forest prediction model with a sensitivity of 61% and a specificity of 84% was developed. Generalized mixed models accounting for the random effect of familial relationships boasted an area under the curve of 0.98.
CONCLUSIONS: Predictive modeling using non-invasive and accessible inputs is a powerful tool to stratify risk for developing atopic dermatitis.

A range of rare mutations involving micro-deletion or -duplication of genetic material (copy number variants (CNVs)) have been associated with high neurodevelopmental and psychiatric risk (ND-CNVs). Irritability is frequently observed in childhood neurodevelopmental conditions, yet its aetiology is largely unknown. Genetic variation may play a role, but there is a sparsity of studies investigating the presentation of irritability in young people with ND-CNVs. This study aimed to investigate whether there is a difference in irritability in young people with rare ND-CNVs compared to those without ND-CNVs, and to what extent irritability is associated with psychiatric diagnoses and cognitive ability (IQ). Irritability and broader psychopathology were assessed in 485 young people with ND-CNVs and 164 sibling controls, using the child and adolescent psychiatric assessment. Autism was assessed using the social communication questionnaire, and intelligence quotient (IQ) by the Wechsler abbreviated scale of intelligence. Fifty four percent of young people with ND-CNVs met the threshold for irritability; significantly more than controls (OR = 3.77, CI = 3.07-7.90, p = 5.31 × 10-11). When controlling for the presence of other psychiatric comorbidities, ND-CNV status was still associated with irritability. There was no evidence for a relationship between irritability and IQ. Irritability is an important aspect of the clinical picture in young people with ND-CNVs. This work shows that genetic variation is associated with irritability in young people with ND-CNVs, independent of psychiatric comorbidities or IQ impairment. Clinicians should be aware of this increased risk to inform management and interventions.

BACKGROUND: The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease-associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu-hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early-onset dementia.
METHODS: We studied 3 siblings with suspected NHD. Whole-exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents.
RESULTS: We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early-onset dementia and bone lesions.
CONCLUSIONS: These findings, alongside previous research, elucidate the clinical spectrum of TREM2-related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2-dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2-affected individuals.