A founder truncating variant in GDF1 causes autosomal‐recessive right isomerism and associated congenital heart defects in multiplex Arab kindreds

The genetic basis of congenital heart malformations associated with disruption of left–right (L–R) asymmetry is broad and heterogenous, with variants in over 25 genes implicated thus far. Of these, deleterious variants in the Growth/Differentiation Factor 1 (GDF1) gene have been shown to cause heterotaxy with varied complex heart malformations of left–right patterning, in 23 individuals reported to date, either in monoallelic or biallelic state. We report three unrelated individuals exhibiting right isomerism with congenital heart defects, each originating from a consanguineous kindred of Arab‐Muslim descent. Using whole exome sequencing, a shared novel homozygous truncating c.608G > A (p.W203*) variant in the GDF1 gene was revealed as the molecular basis of their disease. Subsequently, targeted sequencing of this variant showed full segregation with the disease in these families, with a total of over 15 reportedly affected individuals, enabling genetic counseling, prenatal diagnosis, and planning of future pregnancies. Our findings further confirm the association of biallelic GDF1 variants, heterotaxy and congenital heart defects of left–right patterning, and expand the previously described phenotypic spectrum and mutational profile. Moreover, we suggest targeted screening for the p.W203* variant in relevant clinical circumstances.     

Is there a correlation between time of delivery and newborn cord pH?

Purpose: Since more senior and attending physicians work in labor wards during morning shifts, we expect a better delivery outcome during that time period.

Materials and methods: A retrospective study was conducted between 1/2005 and 12/2014. Records of 56 428 singleton deliveries from a tertiary hospital in which cord blood pH was routinely measured at birth were analyzed. Time of birth was divided into shifts: 7 AM–3?PM (morning shift), 3?PM–11?PM (afternoon shift), and 11?PM–7 AM (night shift). Additional stratification compared weekdays and weekend deliveries.

Results: 19?601, 18?429, and 18?398 neonates were born during morning, afternoon, and night shifts, respectively. There was no significant difference in maternal age, neonatal weight, or mean 5-min Apgar score among the three shift periods. Furthermore, there was no correlation between shift time of delivery and newborn acidosis with respect to cord pH less than 7 (0.1% in each time periods, p?=?0.67). Despite the above, instrumental deliveries and cesarean sections were more common in the morning shift compared to the afternoon and night shift, respectively (p?=?0.001 each).

Conclusions: Although shift time of delivery was found to be related to mode of delivery it was not related to either 5-min Apgar score or newborn acidosis as reflected by cord pH.     

A novel design of injectable porous hydrogels with in situ pore formation

The use of injectable porous hydrogels is of great interest in biomedical applications due to their excellent permeability and ease of integration into sites of surgical intervention. By implementing a method that enables the formation in situ of pores with controllable porosity and pore size, it is possible to synthesize bioactive hydrogels that are tailor-made for specific biomedical applications. An emulsion-templating technique was used to encapsulate oil droplets, which are subsequently leached out of the hydrogel to create the porous structure. Pore size and porosity were manipulated by changing oil-to-water ratios and the surfactant concentrations. Highly swellable porous hydrogels were obtained with control over mechanical strength and diffusive properties. The relationship between porosity, pore size, and the hydrogel’s physical and mechanical characteristics was analyzed, and the potential of this material as a protein drug delivery system was demonstrated.     

Targeting glycosylated antigens on cancer cells using siglec-7/9-based CAR T-cells

Chimeric antigen receptor (CAR) T-cells treatment demonstrate the increasing and powerful potential of immunotherapeutic strategies, as seen mainly for hematological malignancies. Still, efficient CAR-T cell approaches for the treatment of a broader spectrum of tumors are needed. It has been shown that cancer cells can implement strategies to evade immune response that include the expression of inhibitory ligands, such as hypersialylated proteins (sialoglycans) on their surface. These may be recognized by sialic acid-binding immunoglobulin-type lectins (siglecs) which are surface receptors found primarily on immune cells. In this regard, siglec-7 and -9 are found on immune cells, such as natural killer cells, T-cells, and dendritic cells and they can promote immune suppression when binding to sialic acids expressed on target cells. In the present study, we hypothesized that it is possible to use genetically engineered T-cells expressing siglec-based CARs, enabling them to recognize and eliminate tumor cells, in a non-histocompatibility complex molecule restricted way. Thus, we genetically modified human T-cells with different chimeric receptors based on the exodomain of human siglec-7 and -9 molecules and selected optimal receptors. We then assessed their antitumor activity in vitro demonstrating the recognition of cell lines from different histologies. These results were confirmed in a tumor xenograft model exemplifying the potential of the present approach. Overall, this study demonstrates the benefit of targeting cancer-associated glycosylation patterns using CAR based on native immune receptors and expressed in human primary T-cells.     

Synchronous caregiving from birth to adulthood tunes humans’ social brain

Mammalian young are born with immature brain and rely on the mother’s body and caregiving behavior for maturation of neurobiological systems that sustain adult sociality. While research in animal models indicated the long-term effects of maternal contact and caregiving on the adult brain, little is known about the effects of maternal–newborn contact and parenting behavior on social brain functioning in human adults. We followed human neonates, including premature infants who initially lacked or received maternal–newborn skin-to-skin contact and full-term controls, from birth to adulthood, repeatedly observing mother–child social synchrony at key developmental nodes. We tested the brain basis of affect-specific empathy in young adulthood and utilized multivariate techniques to distinguish brain regions sensitive to others’ distinct emotions from those globally activated by the empathy task. The amygdala, insula, temporal pole (TP), and ventromedial prefrontal cortex (VMPFC) showed high sensitivity to others’ distinct emotions. Provision of maternal–newborn contact enhanced social synchrony across development from infancy and up until adulthood. The experience of synchrony, in turn, predicted the brain’s sensitivity to emotion-specific empathy in the amygdala and insula, core structures of the social brain. Social synchrony linked with greater empathic understanding in adolescence, which was longitudinally associated with higher neural sensitivity to emotion-specific empathy in TP and VMPFC. Findings demonstrate the centrality of synchronous caregiving, by which infants practice the detection and sharing of others’ affective states, for tuning the human social brain, particularly in regions implicated in salience detection, interoception, and mentalization that underpin affect sharing and human attachment.

Being born a mammal implies that the brain is immature at birth and develops in the context of the mother’s body, lactation, and caregiving behavior (1). Infants rely on the provisions embedded in the mother’s body, sensory stimuli (2), and the expression of well-adapted caregiving for maturation of neurobiological systems that sustain participation in the social world. Extant research in animal models has shown that breeches in the mother’s continuous presence and variability in the consistency of caregiving carry long-term effects on brain structure and function, particularly on systems that underpin sociality, and these effects are maintained throughout life, altering the adult animal’s capacity to coordinate social bonds, manage hardships, and parent the next generation (3, 4). However, while the human brain is slowest to mature and requires the most extended period of dependence (5), the long-term consequences of caregiving for the human social brain are largely unknown. The current birth-to-adulthood study examines the effects of maternal–newborn skin-to-skin contact (Kangaroo Care, KC) and parent–child social synchrony experienced across development on the brain’s empathic response to others’ emotional states in young adulthood. Social synchrony describes the coordination between the parent’s and child’s nonverbal behavior and communicative signals during social interactions in ways that enhance positivity, reciprocity, and mutual engagement (6, 7), and we tested its longitudinal impact on the brain basis of empathy, a core feature of the social brain.The human social brain integrates activity of subcortical, paralimbic, and cortical structures to sustain human social life, which requires rapid processing of social inputs, top–down regulation of intention and affect, and coordination of the two into the present moment (8). The social brain has undergone massive expansion across primate evolution to support humans’ exquisite social skills, communicative competencies, and mindreading capacities. It has been suggested that Homo sapiens’ success over other hominin owes to their unique empathic abilities, which allow humans to quickly identify and mentally share others’ affective states (9). Such multifaceted empathy, which integrates automatic identification of others’ distinct emotions with the ability to use interoceptive signals to detect others’ specific affect and the capacity to reflect on the changing emotional states of social partners, marks a fundamental achievement of the human social brain. The empathic social brain, in turn, enabled humans to coordinate actions for survival, fine-tune communicative signal systems, and partake in the joys and sorrows of others (10). Yet, while empathy is a core feature of human sociality that is tuned in mammals by patterns of parental care, the relational precursors of the neural empathic response have not been fully explored in human studies.Social synchrony is first observed in the third month of life when parents begin to coordinate with the infant’s nonverbal signals and interactive rhythms. Synchrony continues to mature across childhood and adolescence with the parent’s and child’s increasing reciprocity and adaptation to each other’s verbal and nonverbal communications, affective state, and pace of dialogue and is considered a prototypical experience that prepares children to life with others (11, 12). Through ongoing adaptation first to the infant’s nonverbal cues and then to the older child’s verbal and affective communications, parents orient children to social moments, practice rapid assessment of distinct emotional states, and, over time, enable children to simulate others’ mental states, fine-tuning the social brain and its capacity for empathy (13). Social synchrony undergoes maturation across development and evolves from nonverbal matching to a verbal dialogue that acknowledges others’ emotions, engages multiple perspectives, and reflects on feelings while retaining the interactive rhythms of the familiar dialogue from infancy to adulthood (1). The early experience of synchrony plays a key role in children’s social–emotional development and has been shown to predict the child’s later ability to engage with peers (14, 15), regulate emotions (4), exhibit cognitive control (16), manage stress (17), and display empathic understanding (18), indicating that improvements in mother–infant synchrony during its early stages may have long-term effects on the capacity for empathy and its neural underpinnings.The development of synchrony is highly sensitive to initial conditions. Conditions that compromise maternal–infant bonding bear long-term negative consequences for the development of social synchrony and, consequently, for maturation of human social abilities (19, 20). When infants are born prematurely and full maternal–infant bodily contact is initially lacking, the development of synchrony is halted and socioemotional competencies compromised. Notably, when we provided structured maternal–infant skin-to-skin contact (KC) to premature neonates during the postpartum period, the intervention improved not only social synchrony but also the functioning of regulatory support systems, such as circadian rhythmicity, autonomic maturity, stress responsivity, and exploratory behavior, the same systems that are shaped in young mammals by contact with the mother’s body (17, 18) and consistent presence (21).What may be the effects of maternal–newborn skin-to-skin contact and synchronous caregiving across development on the social brain in young adulthood? Utilizing our unique cohort, we imaged the neural empathic response in three groups of healthy young adults who were recruited at birth: infants born at full-term (FT), preterm infants receiving kangaroo contact (KC), and demographically and medically matched preterm infants receiving standard incubator care (SC) who were followed in our laboratory for two decades (Fig. 1A). We focused on the neural basis of empathy, particularly on the brain’s capacity to detect, affectively share, reflect, and empathize with the different emotions of others (22). Two key hypotheses were tested. First, we expected that the provision of maternal bodily contact in the neonatal period would enhance the expression of social synchrony in infancy and across development. This hypothesis is based on research in animal models which shows that maternal bodily contact, consistent presence, and sensory stimuli improve maternal caregiving and have long-term effects on brain and behavior (21, 23–25). Second, we hypothesized that the experience of synchrony would augment the brain’s capacity to differentiate among others’ emotional states. Synchrony is a dyadic experience by which infants practice the identification and sharing of others’ emotions and, as they develop, learn to imbue others’ feelings with meaning and representations (26). We expected that such practice would tune the brain of young adults to empathize with others’ distinct emotions, particularly in areas that have been linked with parent–child synchrony in the parental brain, the amygdala (27, 28) and insula (29).Open in a separate windowFig. 1.Birth-to-adulthood longitudinal study design and fMRI paradigm. (A) Three cohorts of infants and parents recruited at birth: full-term (FT) infants and two case-matched neurologically intact premature infants assigned to either Kangaroo Care (KC: infants receiving skin-to-skin contact with mother) or matched controls receiving standard incubator care (SC). Mother–child social synchrony was assessed at 4 mo (SD =1.14), 3 y (SD = 1.38), 12 y (SD = 1.62), and 20 y (SD = 2.01). (B) fMRI empathy paradigm. Example illustrates a pseudorandomized design in which participants were presented with an emotional probe followed by four photos depicting this probe. Participants were asked to empathize with the protagonists, and five blocks per condition were presented.Using a longitudinal sample of n = 96 young adults who were followed from infancy, we first examined the neural basis of affect-specific empathy. We employed a validated functional MRI (fMRI) paradigm that exposed participants to others’ distinct emotions (joy, sadness, and distress) and asked them to mentally empathize with the protagonists (30) (Fig. 1B). Consistent with prior imaging studies on the brain regions activated during empathy tasks (31–33), we focused on a network of regions sustaining empathy. This included limbic regions: the amygdala, a key player in emotion detection (34), and the parahippocampal gyrus. Also included were the anterior insula, superior temporal sulcus (STS), and temporal pole (TP) that have been repeatedly implicated in human empathy research (32, 35). We also examined the ventromedial prefrontal cortex (VMPFC), precuneus, and inferior parietal gyrus, known as hubs of the default mode network, which is related to self-referential processing, perspective-taking, and theory of mind tasks (36, 37) and plays a key role in social understanding (38).We used Representational Similarity Analysis (RSA), a multivariate brain pattern analytic technique, to differentiate brain areas that show a distinct neural pattern while empathizing with specific affective states from those generally activated by the empathy task but without a unique response to each emotion. By using RSA, we aimed to compare the distinct neural patterns activated during empathy to different emotions and characterize the brain basis of affect-specific empathy (39). A recent study employing RSA to pinpoint the neural signature of basic emotions indicated that the amygdala, insula, medial prefrontal cortex, frontal pole, and precuneus showed distinct representations for different emotional states (40). Consequently, and in light of research highlighting the role of the amygdala in fear (41) and empathy for negative affective states (42), we focused on the amygdala as a key area that may present differential response during empathy to positive versus negative emotions. Similarly, the insula exhibits similar activations during empathy for physical pain and emotional distress (43, 44), and we expected the insula to show differential activations during empathy to distressing versus nondistressing affective states. Areas including the dorsomedial prefrontal cortex (DMPFC), VMPFC, insula, TP, and precuneus have been shown in research using multivoxel pattern analysis to display specific activation patterns to emotion-related actions and mentalization (36), and we expected these areas to exhibit specific activation patterns during empathy with others’ distinct emotions.     

A Novel Mutation in a Critical Region for the Methyl Donor Binding in DNMT3B Causes Immunodeficiency,Centromeric Instability,and Facial Anomalies Syndrome (ICF)

Purpose

Immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is an extremely rare autosomal recessive disease. The immune phenotype is characterized by hypogammaglobulinemia in the presence of B cells. T cell lymphopenia also develops in some patients. We sought to further investigate the immune defect in an ICF patient with a novel missense mutation in DNMT3B and a severe phenotype.

Methods

Patient lymphocytes were examined for subset counts, immunoglobulin levels, T and B cell de novo production (via excision circles) and receptor repertoire diversity. Mutated DNMT3B protein structure was modeled to assess the effect of a mutation located outside of the catalytic region on protein function.

Results

A novel homozygous missense mutation, Ala585Thr, was found in DNMT3B. The patient had decreased B cell counts with hypogammaglobulinemia, and normal T cell counts. CD4⁺ T cells decreased over time, leading to an inversion of the CD4⁺ to CD8⁺ ratio. Excision circle copy numbers were normal, signifying normal de novo lymphocyte production, but the ratio between naïve and total B cells was low, indicating decreased in vivo B cell replication. T and B cell receptor repertoires displayed normal diversity. Computerized modeling of the mutated Ala585 residue suggested reduced thermostability, possibly affecting the enzyme kinetics.

Conclusions

Our results highlight the existence of a T cell defect that develops over time in ICF patient, in addition to the known B cell dysfunction. With intravenous immunoglobulin (IVIG) treatment ameliorating the B cell defect, the extent of CD4⁺ lymphopenia may determine the severity of ICF immunodeficiency.

     

Diaphanospondylodysostosis: Refining the prenatal diagnosis of a rare skeletal disorder

Diaphanospondylodysostosis (DSD) is a rare autosomal recessive skeletal disorder, characterized mainly by ossification defects in vertebrae, thorax malformations, renal cystic dysplasia and usually death in the perinatal period. DSD is caused by mutations in the bone morphogenetic protein-binding endothelial regulator (BMPER) gene. We describe the prenatal findings of a non-consanguineous Jewish couple (shared Balkan origin), with three affected fetuses that presented with malformations in the spine and chest, reduced ossification of the skull and spine, horseshoe kidney and increased nuchal translucency. The unique combination of these ultrasound (US) features raised the possibility of DSD, which was confirmed by whole exome sequencing (WES) performed on a single fetal DNA and familial segregation. In the three fetuses, a novel homozygous mutation in BMPER (c.410T?>?A; p.Val137Asp) was found. This mutation, which segregated in the family, was not found in 65 controls of Jewish Balkan origin, and in several large databases. Taken together, the combination of a detailed prenatal US examination and WES may be highly effective in confirming the diagnosis of a rare genetic disease, in this case DSD.