The research, led by Elahe Karimi-Shahrbabak and Meta van den Heuvel, used a sequential mixed-methods design, a structure in which each stage feeds the next. First came in-depth interviews with nine purposively selected caregivers about their financial experiences during neonatal intensive care admission and the follow-up period. Those qualitative findings then shaped a cross-sectional survey of 110 caregivers, which measured financial strain, practical problems, and access to financial support. Finally, caregivers, healthcare providers, and researchers gathered in a co-design workshop to interpret the combined evidence and collaboratively draft the program specifications. This triangulation of interview, survey, and workshop data is what gives the study its technical weight: the numbers reveal the scale of the problem, while the stories and the workshop reveal what a solution must actually look like.

The survey results are stark. Respondents were predominantly female (94 of 109, or 86.2 percent) and from two-parent households (96 of 109, or 88.1 percent), yet 43 of 106 caregivers (40.6 percent) reported difficulty making ends meet, and 31 of 107 (29.0 percent) screened positive for household food insecurity. More than half (58 of 108, or 53.7 percent) had no assistance at all navigating financial programs, and 39 of 108 (36.1 percent) reported a financial problem within the past week. These are families already stretched by the demands of caring for a medically fragile infant, and the data suggest that financial distress is not an edge case but a routine feature of the neonatal follow-up population.

The interviews added texture to those figures. Caregivers described income loss during prolonged hospitalization, high out-of-pocket costs for travel, meals, and parking, and the sheer complexity of benefit and tax processes. Programs such as the Ontario Disability Support Program (ODSP), Assistance for Children with Severe Disabilities (ACSD), and the Northern Health Travel Grant exist on paper, but families reported limited hospital-based financial support to help them access them. The interviews also surfaced something the survey could not: a clear appetite for a hospital-based financial navigator, a dedicated person embedded in the clinical team who could walk families through the paperwork while their child is still in care and after discharge.

Financial hardship in neonatal care is not a new observation, but the SickKids study is among the first to systematically characterize it in a neurodevelopmental follow-up clinic and to translate that characterization into a co-designed service specification. The concept draws on the emerging model of medical-financial partnerships (MFPs), in which healthcare systems integrate financial support services directly into clinical care, and on the medical-financial navigator role that has been piloted in adult oncology, where navigators help patients with insurance, benefits, and debt. Adapting that model to neonatal follow-up required understanding a different set of stressors: parents of NICU graduates face years of therapy appointments, equipment costs, and caregiving demands that keep one parent out of the workforce long after discharge.

The co-design workshop, the study’s third and most distinctive stage, brought caregivers, clinicians, social workers, legal health professionals, and researchers to the same table. Participants identified six design themes and prioritized four key specifications: universal access, meaning the navigator should be offered to all families rather than only those who self-identify as struggling; flexible communication, so families can engage by phone, email, or in person at their convenience; timely post-discharge engagement, because financial problems often peak in the weeks after a baby comes home; and a defined set of key services covering benefits applications, tax credits, insurance, and travel supports. The emphasis on universal access is technically significant: it sidesteps the screening problem, in which families who most need help are least likely to disclose distress, and instead normalizes financial navigation as part of standard care.

That normalization matters because financial toxicity, the term borrowed from oncology to describe the harm caused by the cost of care, is increasingly recognized as a determinant of child health. Food insecurity in nearly a third of surveyed households is not merely a budgeting issue; it is a risk factor for poorer developmental outcomes in the very children the NNFU clinic exists to monitor. The study’s authors argue that integrating financial navigation into the follow-up clinic could improve equitable access to financial resources, and that the next step is to pilot and implement the co-designed program and formally evaluate its impact.

The study is formative by design, meaning it was built to shape a future intervention rather than to test one. The authors are explicit that the next phase is to pilot the Financial Navigator Program and evaluate whether it actually improves families’ access to benefits and reduces financial strain. That evaluation will need to account for the realities of a tertiary pediatric hospital: staffing, funding, and the challenge of reaching families who may disengage from follow-up care precisely because of the financial pressures the program is meant to relieve.

What makes the SickKids work resonate beyond Toronto is its methodological honesty. The team did not assume they knew what families needed; they asked, measured, and then co-designed with the people who would use the service. Caregivers were not subjects but partners, including a lived-experience advisor embedded in the author team. The result is a program specification grounded in evidence and shaped by the families it is meant to serve, a model that other hospitals with neonatal follow-up clinics, and indeed any pediatric service where the cost of care quietly erodes family stability, could adapt. The study’s findings, published open access, offer a blueprint for turning a hidden crisis into a structured, navigable pathway.

The broader implication is that financial navigation belongs in the clinical team, not in a pamphlet rack. Nearly a third of surveyed households faced food insecurity, and more than half had no help navigating the supports that exist for exactly their situation. If a hospital can embed a navigator in the follow-up clinic, the argument goes, it can convert a fragmented, opaque benefits landscape into a structured pathway, and in doing so address a determinant of child health that has long been invisible in the exam room. The SickKids team has now built the specifications; the pilot will tell whether the model delivers on its promise.

Subject of Research: Co-designing a financial navigator program in the neonatal neurodevelopmental follow-up clinic: a formative mixed-methods study

Article Title: Co-designing a financial navigator program in the neonatal neurodevelopmental follow-up clinic: a formative mixed-methods study

Article References: Karimi-Shahrbabak, E., Nadarajah, J., Buchanan, F., Perera, S., Danguecan, A., Casey, M., Masemann, R., Medeiros, P., Beck, R., Koziorz, D., Lazor, T., Meserve, A., Ly, L. G., Birken, C. S., & van den Heuvel, M. (2026). Co-designing a financial navigator program in the neonatal neurodevelopmental follow-up clinic: a formative mixed-methods study. BMC Health Services Research. https://doi.org/10.1186/s12913-026-15693-7

Image Credits: AI Generated

DOI: 10.1186/s12913-026-15693-7

Keywords: Co-designing, financial, navigator, program, neonatal, neurodevelopmental, follow-up, clinic, formative, mixed-methods, scientific research

The variant in question, HNRNPH2-R114W, affects a gene on the X chromosome that encodes a member of the heterogeneous nuclear ribonucleoprotein family. These proteins bind G-rich RNA motifs and help decide where precursor messenger RNA is cut and rejoined during splicing, the process that generates the diverse protein-coding transcripts a cell needs. Pathogenic variants in HNRNPH2 cause Bain type X-linked syndromic intellectual developmental disorder, a condition marked by severe developmental delay, absence of verbal communication, impaired ambulation, seizures, and prominent autistic features. The individual whose cells seeded this study carries a de novo heterozygous R114W missense variant and exhibits precisely this severe clinical profile.

To study the variant in a controlled setting, the team reprogrammed the patient’s peripheral blood mononuclear cells into induced pluripotent stem cells using non-integrating episomal vectors. One stem cell line, designated Minus, retained the R114W variant. A second line, designated Plus, was generated by correcting the HNRNPH2 locus with CRISPR-Cas9 within the same genetic background, and Sanger sequencing confirmed the correction-associated sequence changes in edited clones. Both lines maintained strong nuclear expression of the pluripotency markers POU5F1 and NANOG, and both were differentiated into cerebral organoids following a modified Lancaster protocol that included embryoid body formation, neural induction, Matrigel embedding, and suspension maturation.

Imaging told a reassuring story about gross development. Whole-mount immunostaining showed PAX6-positive progenitors arranged in radial, ventricular-like zones around central lumens, with TUBB3-positive neurons localizing to peripheral regions in both genotypes. Organoids from the variant and corrected lines were comparable in size and morphology, with no observable structural abnormalities. HNRNPH2 immunofluorescence, however, revealed genotype-dependent differences: corrected organoids showed signal concentrated in neuroepithelial regions, while variant organoids exhibited weaker and more diffuse staining. The authors interpret this as an indirect indicator of altered HNRNPH2 distribution rather than definitive evidence of reduced protein abundance, since the assay relied on immunofluorescence alone without orthogonal protein quantification.

The transcriptomic analysis, though exploratory in design, produced striking results. Bulk RNA sequencing was performed on pooled RNA from approximately twelve organoids per genotype, each pool sequenced in two technical reactions at a single developmental time point. Differential expression analysis with DESeq2 showed near-complete separation of the two genotypes along the first principal component, which accounted for 99.5 percent of the variance. Thousands of genes were differentially expressed at a false discovery rate of 0.05, with roughly equal numbers upregulated and downregulated. Genes downregulated in variant organoids were enriched for neuron differentiation, axon development, and synaptic transmission, while upregulated genes pointed toward WNT and NOTCH signaling, melanogenesis, tyrosine metabolism, and retinoid biosynthesis.

The splicing findings were even more dramatic. Using SGSeq to quantify both annotated and novel splice junctions supported by split reads, the researchers identified 6,310 differentially used junctions out of roughly 98,000 examined, meaning about six to seven percent of all junctions were significantly altered. By contrast, the exon-focused workflow, which used featureCounts and voom-limma diffSplice testing, found only 17 significant exons. This junction-dominant pattern is biologically coherent: HNRNP H-family proteins regulate splice-site selection at G-rich motifs, so a variant that disrupts their RNA engagement would be expected to reorganize local donor-acceptor usage rather than simply delete exons. Corrected organoids showed increased junction usage in genes such as TUBA1A, TUBB3, CNTN2, and CKB, while variant organoids showed higher usage in DCT, PMEL, ALDH1A3, RDH10, CALB1, and XIST.

Computational structural modeling provided a mechanistic hypothesis for how the variant acts. The researchers built a composite model of HNRNPH2’s three quasi-RNA recognition motifs from available crystal structures and docked it relative to the spliceosomal B complex. In this arrangement, residue R114 sits near a predicted RNA-contact interface within the RRM2 domain, positioned in a geometry compatible with direct RNA interactions. The R114W substitution, replacing a positively charged arginine with a bulky tryptophan, would be predicted to alter this interface and change how the protein engages its RNA targets. The authors emphasize that this docking framework is hypothesis-generating and requires extended simulations and direct structural validation, for example through cryo-electron microscopy.

To organize the multi-layered RNA signals, the team developed an integrated prioritization framework that combined differential expression, event-level splicing significance, and isoform-level remodeling into a composite score per gene. This analysis identified regulatory hubs enriched for axon guidance and synaptic signaling, including CNTN2 and NCAM1, which are critical for cortical wiring, along with TRPM3, HES5, HES6, RTN4, and HMGCS1, which participate in neuronal excitability, neurogenesis, and metabolic support. Some genes, such as RUFY3, EFS, SPAG9, CRMP1, HNRNPC, UTRN, and EVL, showed significant splicing changes without detectable expression shifts, indicating post-transcriptional regulation of neuronal projection and cytoskeletal pathways. Others, including CDH6 and PTPRS, exhibited combined transcriptional and exon-usage alterations.

A key question in organoid transcriptomics is whether apparent gene expression changes reflect genuine regulatory effects or merely shifts in cell-type composition. To address this, the researchers applied MuSiC deconvolution against the human neural organoid cell atlas, a single-cell reference of neurodevelopment. Both genotypes contained mixtures of neuroepithelium, dorsal and ventral telencephalic neurons, glioblasts, oligodendrocyte progenitors, and astrocytes. Variant organoids showed modest enrichment of neuroepithelial and glial-associated fractions and a neuronal fraction approximately five percent lower than corrected organoids. Curated marker heatmaps supported this inference, with progenitor markers such as PAX6 and SOX2 and astrocyte markers GFAP, S100B, and AQP4 showing genotype-linked patterns. The authors conclude that these modest compositional shifts are unlikely to account for the extent of transcriptional and splicing alterations observed, suggesting the variant biases developmental timing toward progenitor and glial states rather than causing neuronal loss.

The findings support a model in which HNRNPH2 variants disrupt post-transcriptional regulation through altered protein localization, splicing, and ribonucleoprotein assembly, producing toxic or dominant-negative effects rather than simple loss of function, with limited compensation by the paralog HNRNPH1. Beyond clarifying disease mechanism, the study nominates candidate isoform-level endpoints for therapeutic investigation, including assessment of allele-selective antisense oligonucleotide strategies and HNRNPH2 modulation in human cortical organoids. The authors also propose that their integrative methodology, combining differential expression, multi-layer splicing analysis, and single-cell-based deconvolution, could be applied to other RNA-binding protein-driven neurodevelopmental disorders, opening avenues to examine how HNRNPH2-associated RNA dysregulation evolves across developmental time and recurs across independent biological contexts.

Subject of Research: HNRNPH2-R114W remodels RNA splicing and neurodevelopmental gene programs in isogenic cerebral organoids

Article Title: HNRNPH2-R114W remodels RNA splicing and neurodevelopmental gene programs in isogenic cerebral organoids

Article References: Caiaffa, C. D., Ghousifam, N., Watkins, S. L., Nakaya, H. I., Bowling, R. A., Jr., Finnell, R. H., & Cabrera, R. M. (2026). HNRNPH2-R114W remodels RNA splicing and neurodevelopmental gene programs in isogenic cerebral organoids. Frontiers in Bioengineering and Biotechnology, 14, Article 1922305. https://doi.org/10.3389/fbioe.2026.1922305

Image Credits: AI Generated

DOI: 10.3389/fbioe.2026.1922305

Keywords: HNRNPH2-R114W, remodels, splicing, neurodevelopmental, gene, programs, isogenic, cerebral, organoids, scientific research

The three genes under investigation sit at the heart of synaptic plasticity, the molecular machinery that allows connections between neurons to strengthen or weaken with experience. FMR1 mutations cause Fragile X syndrome, an inherited condition affecting roughly 1 in 4,000 males and 1 in 7,000 females, in which a CGG repeat expansion on the X chromosome silences production of the FMRP protein. FMRP is strongly expressed in neurons of the cortex, hippocampus, thalamus, and cerebellum, and its loss disrupts spine formation and pruning, synaptic plasticity, and protein synthesis. SYNGAP1, by contrast, encodes a protein found in the postsynaptic density, and mutations of this gene account for up to 1 percent of all non-syndromic intellectual disability. GRIN2B governs expression of the GluN2B subunit of the NMDA receptor, a molecular gatekeeper of plasticity itself. All three conditions are associated with IQs of 70 or below in affected males, making them among the most consequential monogenic causes of cognitive impairment known.

Yet when scientists have tried to reproduce these human deficits in rodents, the results have been maddeningly inconsistent. Studies of Fmr1 knockout mice have reported everything from modest water maze impairments to no deficits at all, depending on strain, task, and laboratory. Fmr1 knockout rats have fared no more clearly: one study found fewer platform crossings during probe trials but no difference in quadrant occupancy, while another found no impairment whatsoever in reference memory, reversal learning, or delayed matching to place. The picture in SYNGAP1 models is somewhat more consistent in mice, with impairments reported on T-maze alternation, Barnes maze learning, and water maze probe preference — but even here, some studies found deficits only during the first 15 seconds of a probe trial, with mutant and wild-type mice converging over the full 60 seconds. GRIN2B rodent work has been similarly split, with one mouse study showing impairments in long-term potentiation, long-term depression, and maze performance, while another found no water maze deficits despite a 30 to 50 percent reduction in GluN2B expression.

The research team, led by Anuj Vadher and Paul Dudchenko, suspected that part of the problem lay in the testing paradigm itself. In the traditional Morris water maze, rats swim in a pool of opaque water searching for a submerged platform, using visual landmarks scattered around the laboratory room. But which landmarks the animals actually use — a lantern, a poster, a curtain edge — is assumed rather than demonstrated. The team had recently observed that head direction cells, neurons that putatively underpin the rodent’s sense of direction, show significant alterations in Fmr1 knockout rats. A task that taps the animals’ use of directional information might therefore be especially sensitive to deficits in this model. To make the task genuinely informative, they built a variant in which the only visual landmarks available were four specified objects — a lantern, a white board, a hi-vis jacket, and a sombrero hat — hung on black curtains surrounding the pool. Critically, at the start of each day, the landmarks and the platform were rotated together by a pseudorandom angle, dissociating the platform’s location from any uncontrolled cues in the testing room and rendering the specified landmarks the only reliable external guides.

The pilot work also revealed an unexpected behavioral wrinkle. When tested in an open pool, both mutant and wild-type Fmr1 rats developed an annular search strategy, swimming in circles at roughly the correct distance from the pool walls rather than relying on the landmarks. Radial band analysis confirmed that this ring-search preference was statistically significant in both genotypes. Such a strategy requires no landmark learning at all — the animals simply learn the platform’s distance from the walls. To force genuine landmark use, the team added eight transparent acrylic triangular wall inserts to the pool, dividing it into eight alleyways that opened into a central circle. Now the rats could not simply swim in a ring; they had to swim into and out of each alleyway, making the search far more costly and the use of directional information far more apparent.

Across 10 days of training in this directional water maze, all three mutant models learned the task robustly. Fmr1 knockout rats and their wild-type littermates both showed steep decreases in the time needed to find the hidden platform, and in the platform-removal probe trials — in which the platform stayed submerged and held down by magnets for 60 seconds — both groups showed increasing preference for the target octant, the alleyway containing the platform’s direction. By day 4, both genotypes performed significantly above the 12.5 percent chance level. Remarkably, the Fmr1 knockout rats actually showed a small but significant advantage over wild-type animals in acquisition speed, though the authors attribute this to unusually slow wild-type performance on day 3. In the more robust measure of octant bias during probe sessions, there was no difference between the groups at all.

The Syngap1 heterozygous rats told a similar story, with one nuance. Across two cohorts totaling 8 mutant and 11 wild-type animals, both groups learned the platform direction equally well, with no difference in probe trial octant occupancy. Mutant rats did take slightly longer to find the platform during training — a significant overall genotype effect — but this latency difference never translated into a memory deficit when the platform was removed. The Grin2b heterozygous rats, tested with both males and females, were indistinguishable from wild-type littermates in every measure, and both groups showed significant target octant preference as early as day 2, the fastest learning of any model tested. For a gene whose product directly gates NMDA receptor currents — the very substrate of long-term potentiation — the intact performance is perhaps the most surprising result of the study.

The landmark removal probes delivered the study’s most conceptually significant finding. When three of the four trained landmarks were removed, leaving only one, performance remained above chance for almost every group and almost every landmark, with the exception of the Syngap1 rats, whose preference approached but did not reach statistical significance. Crucially, within each session, some individual animals performed at or below chance while others showed more than 80 percent occupancy of the correct octant. This pattern is inconsistent with configural learning, in which animals triangulate the platform using the full geometry of the landmark array — that strategy would have impaired all animals equally when only one cue remained. Instead, it suggests that different rats had learned directional associations with different individual landmarks, and that each animal’s performance depended on which specific cue happened to survive the deletion. The authors liken this to pattern completion, the same process that keeps hippocampal place fields intact when only a subset of trained landmarks is available.

The implications cut both ways. On one hand, the intact landmark learning in all three models — despite mutations that disrupt RNA binding, postsynaptic signaling, and receptor subunit expression — suggests that basic associative processes are spared in these genetic conditions, and that higher-order tasks involving sensory conflict may be needed to reveal the deficits that clearly exist in affected humans. When a single source of information is sufficient to guide performance, inflexibility in integrating other sensory streams may simply never become apparent. On the other hand, the finding that rats may navigate by individual landmarks rather than landmark configurations — at least in a directional water maze — revises a central assumption of spatial learning research that has gone largely untested for decades. For a field that has long treated the water maze as a window into cognitive map formation, the message is sobering: what looks like map-based navigation may sometimes be a collection of simple stimulus-response associations, each animal carrying its own private compass needle pointed at a single familiar object.

Subject of Research: Intact spatial learning in Fmr1–/y, Syngap1+/–, and Grin2b+/– rat models of neurodevelopmental disorders

Article Title: Intact spatial learning in Fmr1–/y, Syngap1+/–, and Grin2b+/– rat models of neurodevelopmental disorders

Article References: Vadher, A., Duszkiewicz, A. J., Wood, E. R., & Dudchenko, P. A. (2026). Intact spatial learning in Fmr1–/y, Syngap1+/–, and Grin2b+/– rat models of neurodevelopmental disorders. Frontiers in Behavioral Neuroscience, 20, Article 1929983. https://doi.org/10.3389/fnbeh.2026.1929983

Image Credits: AI Generated

DOI: 10.3389/fnbeh.2026.1929983

Keywords: Intact, spatial, learning, Fmr1, Syngap1, Grin2b, models, neurodevelopmental, disorders, scientific research

A research team led by Grazia Maria Giovanna Pastorino of Magna Graecia University of Catanzaro, working with colleagues at the University of Salerno and the University of Messina, recruited 123 children aged 6 to 11 years across two Italian public healthcare centers between 2021 and 2025. The sample comprised 42 children with Autism Spectrum Disorder Level 1, meaning autism without intellectual disability, 43 children with the combined presentation of Attention-Deficit/Hyperactivity Disorder, and 38 typically developing controls matched for age, sex, and socioeconomic status. Diagnoses were validated with gold-standard instruments: the ADOS-2 and ADI-R for autism, and Conners-3 parent and teacher rating scales for ADHD. Children with both conditions were deliberately excluded to isolate what the researchers call pure clinical phenotypes.

The central question was deceptively simple. Executive functions, the top-down regulatory processes of response inhibition, working memory, planning, cognitive flexibility, and attentional control, are known to support social cognition, the capacity to process and respond to socially relevant cues. Social cognition includes affect recognition, the perceptual decoding of emotional expressions, and theory of mind, the ability to attribute beliefs, intentions, and emotions to oneself and others. But it has remained unclear whether the social difficulties seen in autism and ADHD arise from shared executive failures or from disorder-specific neurocognitive wiring. Developmental models propose that executive functions provide the cognitive scaffolding on which theory of mind is built, yet the strength and shape of that scaffolding may differ dramatically across diagnostic profiles.

To find out, the team combined three standardized instruments. The WISC-IV measured cognitive functioning across verbal comprehension, perceptual reasoning, working memory, and processing speed. The BRIEF-2, completed by parents, captured everyday executive behavior at home, with higher T-scores indicating greater dysfunction. Selected NEPSY-II subtests probed performance directly, including Affect Recognition and Theory of Mind for social cognition, and Inhibition, Auditory Attention, Visual Attention, Response Set, and Design Fluency for executive functions. Testing sessions lasted roughly 90 to 120 minutes per child, and all analyses used non-parametric statistics with Bonferroni-corrected post-hoc comparisons, followed by multiple linear regression models within each clinical group.

The comparative results revealed a striking double dissociation. Both clinical groups showed widespread executive and social-cognitive impairments relative to typically developing peers, but their profiles diverged in opposite directions. Children with ADHD performed worst on response inhibition and basic attentional control, scoring significantly below the autism group on the NEPSY-II Inhibition, Visual Attention, and Auditory Attention subtests, and on the BRIEF-2 Inhibit scale, where the ADHD group’s deficit reached a large effect size. Children with autism Level 1, by contrast, showed the deepest impairments in social cognition itself, with Theory of Mind and Affect Recognition scores significantly lower than in ADHD, alongside greater difficulties in cognitive flexibility on the Response Set and Design Fluency tasks and more everyday inflexibility on the BRIEF-2 Shift scale.

Not everything separated the groups. Working memory emerged as a shared endophenotype: both clinical cohorts scored significantly lower than controls on the WISC-IV Working Memory Index, with no significant difference between them, while verbal comprehension, perceptual reasoning, and processing speed remained statistically homogeneous across all three groups. This pattern suggests that some cognitive vulnerabilities cut across traditional diagnostic boundaries, consistent with transdiagnostic models of neurodevelopmental psychopathology, even as other domains remain profile-specific.

The regression models delivered the study’s most consequential insight. In the ADHD group, theory of mind performance was strongly scaffolded by executive functions: a model combining Inhibition, Auditory Attention, and Design Fluency explained 72.2 percent of the variance in theory of mind scores. Affect recognition in ADHD was similarly driven by Inhibition and Visual Attention, accounting for 60.7 percent of variance, with theory of mind notably absent as a predictor. The interpretation is that children with ADHD do not lack social competence per se; rather, their social-cognitive performance collapses under executive load. To solve a theory of mind task, a child with ADHD must sustain attention on the narrative, inhibit premature responses, and flexibly generate solutions, and it is precisely these regulatory resources that are compromised.

In the autism group, the architecture looked fundamentally different. Theory of mind was predicted primarily by Affect Recognition and Response Set, explaining 55.1 percent of variance, with basic inhibitory and attentional resources exerting no direct predictive role. Affect recognition, in turn, was best predicted by theory of mind itself, explaining 32.7 percent of variance, suggesting an intimate interconnection between bottom-up perceptual decoding of faces and top-down mentalizing within the autistic socio-cognitive core. The authors read this as evidence that the social deficit in autism without intellectual disability is primary and pervasive, not merely a downstream consequence of generic executive failure, though it depends on higher-order flexibility and rule monitoring rather than on basic inhibition.

The clinical implications are substantial. If social difficulties in ADHD stem from executive-regulatory deficits while those in autism reflect primary mentalizing and shifting impairments, then rehabilitation cannot be one-size-fits-all. Interventions targeting inhibition and attentional control may unlock social-cognitive gains in ADHD, whereas autism-focused programs must address emotion decoding, perspective taking, and cognitive flexibility directly. The findings support transdiagnostic profiling that enriches categorical diagnoses with fine-grained cognitive mapping, potentially improving early screening during the 6-to-11 window, which the authors identify as a critical period of asynchronous maturation for both executive control and social reasoning.

The study has limitations the authors acknowledge candidly. The cross-sectional design cannot establish causal direction or track how these architectures remodel across adolescence. Excluding comorbid cases, while essential for isolating pure profiles, reduces ecological validity in a clinical world where autism and ADHD frequently co-occur. Parent-report measures on the BRIEF-2 may be shaped by informant perception and family context, and the sample, drawn from two southern Italian centers over five years, limits generalizability across cultures and to other phenotypic variants such as the predominantly inattentive presentation of ADHD. Future work, the team proposes, should add a comorbid ASD-plus-ADHD group to test whether co-occurrence produces additive, synergistic, or entirely novel endophenotypes, and should integrate eye-tracking and functional neuroimaging to quantify the visual strategies, diminished fixation on the eye region in autism, chaotic impulsive scanning in ADHD, that may underlie the distinct profiles revealed here.

Subject of Research: Neuroscience

Article Title: Neurocognitive endophenotypes in neurodevelopmental disorders: social cognition and executive functions in children with Autism Spectrum Disorder Level 1 and Attention-Deficit/Hyperactivity Disorder

Article References: Pastorino, G. M. G., Olivieri, M., Aquino, A., Mungo, N., Suriano, R., & Operto, F. F. (2026). Neurocognitive endophenotypes in neurodevelopmental disorders: social cognition and executive functions in children with Autism Spectrum Disorder Level 1 and Attention-Deficit/Hyperactivity Disorder. Frontiers in Child and Adolescent Psychiatry, 5, Article 1920753. https://doi.org/10.3389/frcha.2026.1920753

Image Credits: AI Generated

DOI: 10.3389/frcha.2026.1920753

Keywords: autism, ADHD, executive functions, social cognition, theory of mind, neurodevelopmental disorders, working memory, neuropsychology, Neurocognitive, endophenotypes, neurodevelopmental, disorders

The review, led by neonatologist Yunus E. Dogan of the University of Florida together with colleagues spanning neonatology, cardiac surgery, and radiology, integrated eleven prospective and retrospective cohort studies published between 2016 and 2025. Its central numbers are sobering. Preoperative brain injury, detected on magnetic resonance imaging performed before any surgical intervention, is found in between 12 and 54 percent of neonates with congenital heart disease. That enormous range reflects differences in lesion definitions, imaging protocols, and cardiac diagnoses across studies, but even the most conservative estimates mean that at least one in eight babies arrives at the cardiac operating table with a brain that has already been injured. After surgery, the burden persists, with new lesions appearing on postoperative scans in a substantial fraction of survivors.

The patterns of injury are distinctive and diagnostically revealing. Before surgery, the most common findings are white matter injury, arterial ischemic stroke, and cerebral hemorrhage. White matter injury, sometimes described as periventricular leukomalacia-like damage, strikes the fatty sheathed fibers that connect distant brain regions and are still being actively myelinated in the third trimester. After surgery, the imaging signature shifts: white matter injury remains dominant, but clinicians also see focal infarctions that are often thromboembolic in origin, tiny microhemorrhages scattered through the parenchyma, and cerebral venous thrombosis. This temporal fingerprint, captured by serial MRI, allows researchers to distinguish lesions that were present at birth from those acquired in the operating room or intensive care unit, and it has fundamentally changed the framing of the problem from a surgical complication to a continuum of vulnerability that begins in utero.

Why is the fetal brain so fragile when the heart is malformed? The answer lies in the peculiar plumbing of fetal circulation and the metabolic demands of the rapidly growing brain. In a normal fetus, the placenta delivers oxygenated blood, and the brain enjoys a privileged, high-flow supply. In fetuses with critical heart defects, however, the anatomy reroutes this flow. In conditions such as hypoplastic left heart syndrome or transposition of the great arteries, oxygen-rich and oxygen-poor blood mix abnormally, and the cerebral circulation may be perfused at lower pressure, lower oxygen content, or both. Advanced fetal MRI studies have measured this directly, showing reduced fetal cerebral oxygen consumption associated with smaller brain size, delayed cortical development correlated with reduced oxygen delivery, and altered hemodynamic responses when mothers are given supplemental oxygen. The result is a brain that reaches birth with globally reduced volumes, microstructural abnormalities in structures like the corpus callosum, and in some cases aberrant functional connectivity detectable before any operation.

The maternal-fetal environment adds another layer of risk. The review highlights evidence linking placental dysfunction and preeclampsia to preoperative focal white matter injury in neonates with complex heart disease, an emerging field some researchers call neuroplacentology. Three-dimensional volumetric MRI of the placenta in fetuses with complex congenital heart disease has revealed measurable differences compared with controls, and placental pathology correlates with neuroimaging abnormalities after birth. In other words, the same compromised maternal-fetal conditions that stress the heart may simultaneously starve the developing brain of oxygen and nutrients. Perinatal and neonatal characteristics compound this vulnerability: male sex, prematurity, and low birth weight all emerge as risk factors, echoing patterns seen in preterm brain injury more broadly. Notably, the immature oligodendrocytes that build myelin in the third trimester are exquisitely sensitive to hypoxia-ischemia and inflammation, which helps explain why white matter bears the brunt of the damage in this population.

Cerebral autoregulation, the brain’s ability to maintain steady blood flow despite swings in blood pressure, appears to be impaired in many of these newborns even before surgery. Studies of preoperative infants with congenital heart disease have documented blunted autoregulatory capacity, and novel noninvasive measures of cerebrovascular stability are being tested against invasive monitoring to bring this physiology to the bedside. The clinical implication is profound: a blood pressure that is perfectly adequate for one baby’s brain may be dangerously low for another’s, and the transition from fetal to neonatal circulation, with its shifting shunts and falling pulmonary resistance, is a period of particular hazard. Preoperative procedures such as balloon atrial septostomy have been scrutinized as potential stroke triggers, though large studies suggest that oxygenation and time to surgery are more important determinants of injury than the procedure itself.

Then comes the operation, and with it a new set of insults. Cardiopulmonary bypass, the heart-lung machine that sustains circulation during repair, exposes the brain to nonphysiological flow, embolic debris, inflammatory activation, and ischemia-reperfusion injury when the heart is restarted. Neonatal blood is uniquely challenging in this setting: standard heparin doses achieve less consistent thrombin inhibition in newborns than in older patients, and the coagulation system swings between thrombosis and bleeding with little margin for error. Anticoagulation strategy, surgical timing, hemodynamic instability, and the use of extracorporeal membrane oxygenation all emerge in the review as procedural risk factors for postoperative brain injury. Focal infarctions after surgery are frequently thromboembolic, and cerebral sinovenous thrombosis has been documented in infants undergoing cardiac surgery, sometimes producing thalamic hemorrhage and requiring difficult anticoagulation decisions in a fragile patient.

There is, however, genuine cause for optimism embedded in the data. The review notes that advances in blood pressure management, tailored perfusion strategies, and optimized surgical timing have already reduced postoperative injury rates, and recent multicenter work has documented a declining incidence of postoperative neonatal brain injury over time. Studies comparing cohorts with different practice approaches show that institutional choices matter, and European collaborative data have begun to map which perioperative factors predict long-term neurodevelopmental outcomes better than conventional imaging alone. The stakes of these improvements are high: perioperative brain injury on neonatal MRI is associated with worse school-age neurodevelopment, reduced white matter volume predicts language difficulties, and hippocampal volume reductions in adolescents with congenital heart disease track with intellectual function. Survivors face elevated rates of motor delay, cognitive and executive function deficits, and abnormalities in brain regions regulating anxiety and mood.

The path forward, as the authors frame it, is precision neuroprotection across the entire continuum of care. Antenatal interventions, including maternal hyperoxia strategies being tested with blood oxygenation level dependent fetal MRI, could potentially bolster the fetal brain before birth. Individualized hemodynamic management targets, guided by continuous cerebral autoregulation monitoring rather than population-wide blood pressure thresholds, could protect the brain during bypass and in the intensive care unit. Multimodal neuromonitoring, incorporating continuous electroencephalography and amplitude-integrated EEG, which has been shown to predict preoperative MRI findings, could catch injury in real time. Risk-stratified anticoagulation could balance clot and bleeding risks, and neuroprotective drugs such as allopurinol are already in phase III randomized trials for babies requiring bypass surgery. Finally, long-term neurodevelopmental surveillance programs would ensure that early injuries, however subtle, are met with early intervention.

For the roughly one percent of newborns whose hearts form differently, the message of this synthesis is both a warning and a promise. The brain injury that shadows congenital heart disease is not an inevitable consequence of a defective heart, nor simply the price of a heroic operation. It is a mechanistically traceable process, visible on MRI from fetal life onward, driven by hypoxemia, impaired autoregulation, inflammation, and thrombosis, and shaped by the placenta, the delivery room, the bypass circuit, and the intensive care unit. Each of those checkpoints is now a target. If the trajectory of declining postoperative injury continues, and if antenatal and precision perioperative strategies mature from promising trials into standard care, the generation of children born with heart defects may one day keep their hearts repaired without paying a hidden neurological price.

Subject of Research: Brain injury mechanisms, MRI patterns, and perioperative risk factors in neonates with congenital heart disease

Article Title: Brain injury in congenital heart disease: pathophysiology, MRI patterns, and perioperative risk factors

Article References: Dogan, Y. E., Vargas-Boggiano, D. A., Bleiweis, M., Philip, J., Narasimhulu, S. S., Tuna, I., & Weiss, M. D. (2026). Brain injury in congenital heart disease: pathophysiology, MRI patterns, and perioperative risk factors. Pediatric Research. https://doi.org/10.1038/s41390-026-05454-x

Image Credits: AI Generated

DOI: 10.1038/s41390-026-05454-x

Keywords: congenital heart disease, brain injury, white matter injury, neonatal stroke, MRI, cardiopulmonary bypass, cerebral autoregulation, placental dysfunction, neuroprotection, neurodevelopmental outcomes, fetal circulation, thromboembolism