Broader autism phenotype as a risk factor for postpartum depression: Hamamatsu Birth Cohort (HBC) Study

AbstractThe broader autism phenotype (BAP), which refers to the expression of behavioral and cognitive propensities that are milder but qualitatively similar to those defining autism spectrum disorder, can play a crucial role in postpartum depression (PPD). We investigated whether pregnant women's BAP would increase the risk for PPD, using a representative birth cohort in Japan. Pregnant women were enrolled in the Hamamatsu Birth Cohort (HBC) Study during their mid-gestation (N=841) and were followed up until 3 months after delivery. BAP was measured mainly during the 2nd trimester of the pregnancy by using the Broader Phenotype Autism Symptoms Scale. Participants scoring 9 points or higher on the Edinburgh Postnatal Depression Scale at least once during the first 3 months after childbirth were diagnosed with PPD. Among participants, 128 (15.2%) women were found to have PPD. Multiple logistic regression analyses showed that BAP were associated with PPD (OR=1.19, 95% CI [1.07–1.31]), even after controlling for other potential confounders. In addition, the association was not moderated by history of depression and/or anxiety disorders, including concurrent depressive and anxiety symptoms during pregnancy. The findings suggest that pregnant women with BAP have an elevated risk for PPD

Polygenic Risk Score Analysis Revealed Shared Genetic Background in Attention Deficit Hyperactivity Disorder and Narcolepsy

Attention deficit hyperactive disorder (ADHD) is a highly heritable neurodevelopmental disorder, and excessive daytime sleepiness is frequently observed in ADHD patients. Excessive daytime sleepiness is also a core symptom of narcolepsy and essential hypersomnia (EHS), which are also heritable conditions. Psychostimulants are effective for the symptomatic control of ADHD (primary recommended intervention) and the two sleep disorders (frequent off-label use). However, the common biological mechanism for these disorders has not been well understood. Using a previously collected genome-wide association study of narcolepsy and EHS, we calculated polygenic risk scores (PRS) for each individual. We investigated a possible genetic association between ADHD and narcolepsy traits in the Hamamatsu Birth Cohort for mothers and children (HBC study) (n=876). Gene-set enrichment analyses were used to identify common pathways underlying these disorders. Narcolepsy PRS were significantly associated with ADHD traits both in the hyperactivity domain (e.g.,P-value threshold \u3c 0.05,β[SE], 5.815 [1.774];P=0.002) and inattention domain(e.g.,P-value threshold \u3c 0.05,β[SE], 5.734 [1.761];P=0.004). However, EHS PRS was not significantly associated with either domain of ADHD traits. Gene-set enrichment analyses revealed that pathways related to dopaminergic signaling, immune systems, iron metabolism, and glial cell function involved in both ADHD and narcolepsy. Findings indicate that ADHD and narcolepsy are genetically related, and there are possible common underlying biological mechanisms for this relationship. Future studies replicating these findings would be warranted to elucidate the genetic vulnerability for daytime sleepiness in individuals with ADHD

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Season of Birth Predicts Emotional and Behavioral Regulation in 18-Month-Old Infants: Hamamatsu Birth Cohort for Mothers and Children (HBC Study)

Background: Previous research has demonstrated that the season of birth may predict development of emotional and behavioral regulation during childhood or adolescence. This study examined whether the season of birth predicts effortful control (i.e., the ability to voluntarily choose course of actions during conflict and to plan for the future) and aggression (i.e., the use of physical force and expression of anger toward others) in 18-month-old infants.Methods: Participants included 885 infants who were enrolled in the Hamamatsu Birth Cohort for Mothers and Children in Hamamatsu, Japan. Seasons of birth were categorized into winter (December, January, and February), spring (March, April, and May), summer (June, July, and August), and autumn (September, October, and November). At 18 months of age, effortful control was assessed using the Early Childhood Behavior Questionnaire, and aggression was measured using the Cardiff Infant Contentiousness Scale. Structural equation modeling analysis with measurement and structural equations was conducted to test our prediction.Results: Effortful control was higher in infants born in spring (B = 0.095, 95% CI [0.014 to 0.175], p = 0.021, = 0.146) and summer (B = 0.078, 95% CI [0.001 to 0.156], p = 0.049, = 0.118) than in those born in winter. In addition, aggression was lower in those born in spring (B = −0.286, 95% CI [−0.551 to −0.021], p = 0.035, = −0.135) than those born in winter, even after controlling for seven covariates.Conclusion: The findings suggest that season of birth may determine development of emotional and behavioral regulation skills during early infancy. Future research should pay more attention to the underlying mechanisms of the effects of birth season on development of emotional and behavioral regulation during infancy