ABSTRACT Introduction Down syndrome (DS), arising from Trisomy 21, is the most common genetic condition associated with intellectual disability. While smaller total brain volumes have been consistently observed in DS, no longitudinal neuroimaging studies have examined volumetric brain development in DS during infancy, a period of rapid neural growth when interventions may have the greatest impact. Method High-resolution T1- and T2-weighted images were acquired during natural sleep in a multisite longitudinal cohort of 44 infants with DS and 39 control infants without DS at ages 6 and 12 months. Neuroimaging data were harmonized to reduce batch effects, and a novel deep-learning, repeated-measures segmentation approach was applied to optimize neuroanatomical segmentations. Total intracranial volume (ICV) and bilateral absolute subcortical volumes (amygdala, caudate, hippocampus, pallidum, putamen, thalamus) were first directly compared in infants with and without DS at 6 and 12 months. Hierarchical linear modeling (HLM) evaluated longitudinal group differences for each structure, accounting for sex, gestational age, and laterality. Subcortical group differences estimated by HLM were also compared to group differences in total ICV. Results ICV in infants with DS was lower than controls at 6 months (12.6%; p< .001) and 12 months (16.3%; p< .001). Subcortical structures displayed a range of lower volumes (6.9%-13.1%; p’s ≤.003) in infants with DS, although the caudate and putamen were exceptions. Caudate volumes were on average lower in DS but not significantly different from controls, while putamen volumes were on average higher in DS but not significantly different from controls, except for the right putamen, which was significantly larger (5.3%; p =.018) at 6 months. In HLM, ICV and all subcortical structures showed slower growth in DS from 6 to 12 months, except for the amygdala and putamen, which displayed similar growth rates to controls. DS-associated reductions in subcortical volumes were similar in magnitude to ICV, although 12-month caudate and 6- and 12-month putamen volumes were enlarged relative to ICV. Conclusion Infants with DS exhibited substantially reduced ICV and widespread reductions in subcortical volumes and growth from 6-12 months. Across a range of volumetric differences, findings were most distinct in the basal ganglia, for which volume reductions were attenuated in the caudate, while the putamen was uniquely enlarged with comparable growth to controls. These observations support early regional specificity in the neural impact of Trisomy 21 and underscore the utility of infant neuroimaging to inform biologically based interventions and clinical trial readiness in DS.

BACKGROUND:In children with Chiari type I malformation and syringomyelia, neurosurgical posterior fossa decompression (PFD) provides clinical improvement, but whether duraplasty (incising the dura and placing a dural graft) improves outcomes is unclear. METHODS:We conducted a multicenter, cluster-randomized, controlled trial of PFD with duraplasty (PFD-D) as compared with PFD alone. Persons 21 years of age or younger with cerebellar tonsillar ectopia of at least 5 mm and a maximum syrinx diameter of 3.0 to 9.9 mm were enrolled at 38 centers. Centers were cluster-randomized: all the participants within each center underwent the same intervention. The primary outcome was surgical complications within 6 months. Secondary outcomes were clinical improvement, syrinx reduction, and repeat decompression at 10 to 24 months and the change in overall health-related quality of life at 6 to 24 months. RESULTS:A total of 162 participants were included in the trial, of whom 78 were assigned to undergo PFD-D and 84 to undergo PFD alone. The percentage of participants with complications within 6 months was 14% with PFD-D and 6% with PFD (adjusted odds ratio, 2.59; 95% confidence interval [CI], 0.86 to 7.84; P = 0.11). At 24 months, the percentage of participants with clinical improvement was 58% with PFD-D and 46% with PFD; the mean (±SD) syrinx reduction was 3.08±2.33 mm and 1.22±1.79 mm, respectively; and the percentage of participants with repeat decompression was 3% and 14%. Changes in health-related quality of life were similar in the two groups. CONCLUSIONS:The percentage of participants with surgical complications did not differ significantly between those who underwent PFD-D and and those who underwent PFD alone. Larger trials are needed to determine the relative benefits and risks of these two procedures. (Funded by the Patient-Centered Outcomes Research Institute and others; ClinicalTrials.gov number, NCT02669836.).

Abnormally increased extra-axial cerebrospinal fluid (EA-CSF) volume is present as early as 6 months in infants later diagnosed with autism and is associated with symptom severity at the age of diagnosis, but it is unknown whether early EA-CSF enlargement has long-term impacts on other clinical domains. Executive function (EF) deficits are frequently observed in children with autism and are linked with worse academic outcomes, higher anxiety, and lower adaptive functioning. The current study examines the association between EA-CSF volume at infancy and EF at school age in a longitudinally phenotyped cohort of children with either high (HL) or low (LL) familial likelihood for autism. In this prospective study, 239 infants underwent MRI scans during natural sleep at 6, 12, and 24 months of age. HL was defined as having an older sibling with autism. The sample was divided into three diagnostic groups: HL infants who were diagnosed with autism at 24 months (HL+, n = 34), HL infants not diagnosed with autism (HL-, n = 131), and LL infants without autism (LL-, n = 74). Two parent-rating scales of EF were collected at the school-age follow-up (Mage= 10.4 years ± 1.34): the Behavior Rating Inventory of Executive Function (BRIEF) and Conners Parent Short Form. ANOVA was used to test for diagnostic group differences in EF. Longitudinal mixed-effects models utilized EA-CSF volumes in infancy to predict EF at school-age, while controlling for IQ, sex, total cerebral volume, and diagnostic group. Consistent with previous literature, HL + participants had greater EF deficits than both HL- and LL- on the BRIEF (F = 18.46, p < .0001) and greater EF deficits than LL- on the Conners (F = 8.55, p < .001). Further, higher EA-CSF volumes during infancy were associated with poorer executive function eight years later on both BRIEF (ß=0.18, p < .001) and Conners (ß=0.18, p < .001). This association between EA-CSF and executive function was observed across familial likelihood and diagnostic groups. Our study indicates that elevations in EA-CSF volumes during infancy, even in those who do not have autism, have long-term associations beyond autism symptomatology. These findings underscore the potential link between infant CSF physiology and future behavioral domains such as executive function at school age.

BACKGROUND AND OBJECTIVES:Agenesis of the corpus callosum (ACC) is a common congenital brain malformation. Early development in ACC remains unexamined, despite the increased likelihood for developmental delays and autistic behaviors. This study compares adaptive functioning in infants/toddlers with isolated ACC to children with other neurodevelopmental conditions and typical development. METHODS:Parents of children with ACC completed the Vineland Adaptive Behavior Scale Interview at 6, 12, 18, and 24 months as part of a prospective longitudinal study. Comparison groups included children with fragile X, Down syndrome, high familial likelihood of autism spectrum disorder (both with and without autism spectrum diagnosis), and typical development (total n = 957; total assessments = 2676). RESULTS:By 24 months, 29% of children with ACC were delayed in at least 1 domain. Linear mixed effect models showed significant group × time point interactions in all domains. Post-hoc comparisons revealed the ACC group had poorer performance in communication by 6, motor by 12, and daily living by 18 months but equivalent socialization compared with typically developing children; stronger skills across most domains and time points compared with genetic groups; and equivalent communication, stronger socialization, and weaker motor skills compared with the autism group. CONCLUSIONS:Although there is significant variability, on average, ACC compromises communication skills by 6 months, with reduced motor and daily living skills by 12 and 18 months, respectively. Multipronged intervention programs are needed for ACC beginning early in the first year of life, possibly leveraging early strengths in social skills.

Human induced pluripotent stem cell (iPSC) derived cortical organoids (hCOs) model neurogenesis on an individual's genetic background. The degree to which hCO phenotypes recapitulate the brain growth of the participants from which they were derived is not well established. We generated up to 3 iPSC clones from each of 18 participants in the Infant Brain Imaging Study, who have undergone longitudinal brain imaging during infancy. We identified consistent hCO morphology and cortical cell types across clones from the same participant. hCO cross-sectional area and production of cortical hem cells were associated with in vivo cortical growth rates. Cell cycle associated genes expression in early progenitors at the crux of fate decision trajectories were correlated with cortical growth rate from 6-12 months of age, and were enriched in microcephaly and neurodevelopmental disorder genes. Our data suggest the hCOs capture inter-individual variation in cortical cell types influencing infant cortical surface area expansion.

Autism spectrum disorder (ASD) is highly heritable and phenotypically variable. Neuroimaging markers reflecting variation in behavior will provide insights into circuitry subserving core features. We examined functional correlates of ASD symptomology at school-age, while accounting for associated behavioral and cognitive domains, in a longitudinal sample followed from infancy and enriched for those with a genetic liability for ASD. Resting state functional connectivity MRIs (fcMRI) and behavioral data were analyzed from 97 school-age children (8.1–12.0 years, 55 males, 15 ASD) with (n = 63) or without (n = 34) a family history of ASD. fcMRI enrichment analysis (EA) was used to screen for associations between network-level functional connectivity and six behaviors of interest in a data-driven manner: social affect, restricted and repetitive behavior (RRB), generalized anxiety, inattention, motor coordination, and matrix reasoning. Functional connectivity between the visual and salience networks was significantly associated with social affect symptoms at school-age after accounting for all other behaviors. Results indicated that stronger connectivity was associated with higher social affect scores. No other behaviors were robustly associated with functional connectivity, though trends were observed between visual-salience connectivity and RRBs. Connectivity between the visual and salience networks may play an important role in social affect symptom variability among children with ASD and those with genetic liability for ASD. These findings align with and extend earlier reports in this sample of the central role of the visual system during infancy in ASD.

Down syndrome (DS), resulting from Trisomy 21, is the most prevalent chromosomal disorder and a leading cause of intellectual disability. Despite the significant impact of Trisomy 21 on brain development, research on white matter (WM) microstructure in infants with DS remains limited. While widespread reductions in WM integrity have been identified in children and young adults with DS, no study has examined WM microstructure in infancy. This study investigates early WM microstructure in infants with DS using diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI). Forty-nine infants with DS (28 [57.14%] female) and 36 control (18 [48.65%] female) infants were scanned at 6 months of age. Infants with DS showed significant reductions in fractional anisotropy and neurite density index across multiple association tracts, particularly in the inferior fronto-occipital fasciculus and superior longitudinal fasciculus II, consistent with reduced structural integrity and neurite density. Increased radial diffusivity was observed in these tracts, a feature associated with disrupted myelination. In the inferior fronto-occipital fasciculus, superior longitudinal fasciculus II, and uncinate fasciculus, an elevated orientation dispersion index suggested increased neurite dispersion and fanning in infants with DS. These findings reveal widespread WM developmental alterations in DS, providing new insights into the early neurodevelopment of DS, which may inform timing of early therapeutic interventions.

Down syndrome (DS) is the most common genetic cause of intellectual disability, but our understanding of white matter microstructure in children with DS remains limited. Previous studies have reported reductions in white matter integrity, but nearly all studies to date have been conducted in adults or relied solely on diffusion tensor imaging (DTI), which lacks the ability to disentangle underlying properties of white matter organization. This study examined white matter microstructural differences in 7- to 12-year-old children with DS (n = 23), autism (n = 27), and typical development (n = 50) using DTI as well as High Angular Resolution Diffusion Imaging, and Neurite Orientation and Dispersion Imaging. There was a spatially specific pattern of results that showed a dissociation between intra- and inter-hemispheric pathways. Intra-hemispheric pathways (e.g., inferior fronto-occipital fasciculus, superior longitudinal fasciculus) exhibited reduced organization and structural integrity. Inter-hemispheric pathways (e.g., corpus callosum projections) and motor pathways (e.g., corticospinal tract) showed denser neurite packing and lower neurite dispersion. The current findings provide early insight into white matter development in school-aged children with DS and have the potential to further elucidate microstructural differences and inform more targeted clinical trials than what has previously been observed through DTI models alone.

fcMRI correlates of autism spectrum disorder (ASD) diagnosis and familial liability were studied in 24-month-olds at high (older affected sibling) and low familial likelihood for ASD. fcMRI comparisons of high-familial-likelihood (HL) ASD-positive (HLP, N = 23) and ASD-negative (HLN, N = 91), and low-likelihood ASD-negative (LLN, N = 27) 24-month-olds from the Infant Brain Imaging Study (IBIS) Network were conducted, employing object oriented data analysis (OODA), support vector machine (SVM) classification, and network-level fcMRI enrichment analyses. OODA (alpha = 0.0167, 3 comparisons) revealed differences in HLP and LLN fcMRI matrices (p = 0.012), but none for HLP versus HLN (p = 0.047) nor HLN versus LLN (p = 0.225). SVM distinguished HLP from HLN (accuracy = 99

Aminoacyl-tRNA synthetases (ARSs) catalyze the formation of aminoacyl-tRNA, which is required for protein translation. A growing number of cases are associated with ARS deficiencies. Pathogenic variants in IARS1 (MIM# 600709), encoding cytoplasmic isoleucyl-tRNA synthetase, have been associated with autosomal recessive growth retardation, impaired intellectual development, hypotonia, and hepatopathy (GRIDHH, OMIM# 617093). To date, 11 GRIDHH patients have been described. We identified a patient who presented with recurrent episodes of liver failure in the setting of preceding infection and neurocognitive delay, and who recently presented with a clinical picture consistent with chronic nonbacterial osteomyelitis/chronic recurrent multifocal osteomyelitis. Exome sequencing revealed that this patient is compound heterozygous for two IARS1 variants: c.1193dupC;p.(Cys400LeufsTer32) and c.746A>G;p.(Asp249Gly). The frameshift variant is predicted to cause a loss of function, and functional analysis of the p.Asp249Gly variant was performed using baker's yeast. Wild-type human IARS1 has been shown to support robust yeast growth in the absence of the yeast ortholog, ILS, while human IARS1 harboring p.Asp249Gly could not, indicating a loss-of-function effect. The proband was treated with isoleucine supplementation with subjective clinical improvement. Overall, we expand the molecular and clinical spectra of the IARS1-related disorder, highlight immune dysregulation as a possible novel manifestation of this disorder, and emphasize the utility of a yeast model system for functional studies. A larger cohort of patients is required to validate these observations and evaluate the efficacy of isoleucine supplementation for patients with GRIDHH.

Induced pluripotent stem cell (iPSC)-derived human cortical organoids (hCOs) model neurogenesis on an individual’s genetic background. The degree to which hCO phenotypes recapitulate the brain growth of the participants from whom they were derived is not well established. We generated up to 3 iPSC clones from each of 18 participants in the Infant Brain Imaging Study, who underwent longitudinal brain imaging during infancy. We identified consistent hCO morphology and cortical cell types across clones from the same participant. hCO cross-sectional area and production of hem/choroid plexus were associated with in vivo cortical growth rates. Cell-cycle-associated gene expression in early progenitors at the crux of fate-decision trajectories was correlated with cortical growth rates from 6 to 12 months of age and was enriched for microcephaly and neurodevelopmental disorder genes. Our data suggest the hCOs capture inter-individual variation in cortical cell types that influences infant cortical surface area expansion.

Most current neuroimaging analyses in studies of brain disorders assume a homogenous presentation of the disorder such that traditional statistical analysis methods based on Gaussian distributions can be applied. Yet, most brain disorders present with a heterogeneous spectrum of cognitive, behavioral, morphometric as well as functional manifestations. In this paper, we introduce a novel approach called PRADA (Phenotype Representation and Analysis via Discriminant Atypicality) that embraces the heterogeneity of both typical and atypical brain morphometry. This approach employs Multiscale Score Matching Analysis (MSMA), a global and local multiscale out-of-distribution analysis via the gradients of the log density (scores). Combining MSMA and manifold-mapping, we compute a morphospace of brain phenotypes representing deviations from a population of typical subjects. Using these brain phenotypes, disorder-related subtyping can be performed. Furthermore, subject-specific profiles of atypicality can be extracted via Spatial-MSMA and summarized per subtype. We show the application of PRADA to structural MRI data in a study of Autism Spectrum Disorder (ASD). The resulting analysis detects disorder-related subtypes and reveals that subtype-specific structural atypicality correlates with cognitive and behavioral outcomes. These results highlight the potential of PRADA to discover disorder relevant phenotypes.

Central nervous system (CNS) injury is common in sickle cell disease (SCD) and occurs early in life. Hydroxyurea is safe and efficacious for treatment of SCD, but high-quality evidence from randomized trials to estimate its neuroprotective effect is scant. HU Prevent was a randomized (1:1), double-blind, phase II feasibility/pilot trial of dose-escalated hydroxyurea vs. placebo for the primary prevention of CNS injury in children with HbSS or HbS-β0-thalassemia subtypes of SCD age 12-48 months with normal neurological examination, MRI of the brain, and cerebral blood flow velocity. We hypothesized that hydroxyurea would reduce by 50% the incidence of CNS injury. Two outcomes were compared: primary-a composite of silent cerebral infarction, elevated cerebral blood flow velocity, transient ischemic attack, or stroke; secondary-a weighted score estimating the risk of suffering the consequences of stroke (the Stroke Consequences Risk Score-SCRS), based on the same outcome events. Six participants were randomized to each group. One participant in the hydroxyurea group had a primary outcome vs. four in the placebo group (incidence rate ratio [90% CI] 0.216 [0.009, 1.66], p = .2914) (~80% reduction in the hydroxyurea group). The mean SCRS score was 0.078 (SD 0.174) in the hydroxyurea group, 0.312 (SD 0.174) in the placebo group, p = .072, below the p-value of .10 often used to justify subsequent phase III investigations. Serious adverse events related to study procedures occurred in 3/41 MRIs performed, all related to sedation. These results suggest that hydroxyurea may have profound neuroprotective effect in children with SCD and support a definitive phase III study to encourage the early use of hydroxyurea in all infants with SCD.

BackgroundBoth perinatal arterial ischemic stroke (PAIS) and hypoxic-ischemic encephalopathy (HIE) can present with neonatal encephalopathy. We hypothesized that among infants undergoing therapeutic hypothermia, presence of PAIS is associated with a higher risk of seizures and a lower risk of persistent encephalopathy after rewarming.MethodsWe studied 473 infants with moderate or severe HIE enrolled in the HEAL Trial who received a brain MRI. We defined PAIS as focal ischemic infarct(s) within an arterial distribution, and HIE pattern of brain injury as central gray, peripheral watershed, or global injury. We compared the risk of seizures (clinically suspected or electrographic), and of an abnormal 5-day Sarnat exam, in infants with and without PAIS.ResultsPAIS was diagnosed in 21(4%) infants, most of whom (16/21, 76%) also had concurrent HIE pattern of brain injury. Infants with PAIS were more likely to have seizures (RR 2.4, CI 2.8-3.3) and persistent moderate or severe encephalopathy on 5-day Sarnat exam (RR 2.5, 95% CI 1.9-3.4).ConclusionAmong infants undergoing therapeutic hypothermia, PAIS typically occurs with concurrent HIE pattern brain injury. The higher rate of encephalopathy after rewarming in infants with PAIS may be due to the frequent co-existence of PAIS and HIE patterns of injury.

BackgroundDue to the risk of cerebral vascular injury, children and adolescents with high-risk sickle cell disease (SCD) experience neurocognitive decline over time. Haploidentical stem cell transplantation (HISCT) from human leukocyte antigen-matched sibling donors may slow or stop progression of neurocognitive changes.ObjectivesThe study is to determine if HISCT can ameliorate SCD-associated neurocognitive changes and prevent neurocognitive progression, determine which specific areas of neurocognitive functioning are particularly vulnerable to SCD, and determine if there are age-related differences in neurocognitive functioning over time.MethodsWe performed neurocognitive and neuroimaging in SCD recipients following HISCT. Children and adolescents with high-risk SCD who received parental HISCT utilizing CD34+ enrichment and mononuclear cell (T-cell) addback following myeloimmunoablative conditioning received cognitive evaluations and neuroimaging at three time points: pre-transplant, 1 and 2 years post-transplant.ResultsNineteen participants (13.1 ± 1.2 years [3.3–20.0]) received HISCT. At 2 years post-transplant, neuroimaging and cognitive function were stable. Regarding age-related differences pre-transplantation, older children (≥13 years) had already experienced significant decreases in language functioning (p < 0.023), verbal intelligence quotient (p < 0.05), non-verbal intelligence quotient (p < 0.006), and processing speed (p < 0.05), but normalized post-HISCT in all categories.ConclusionThus, HISCT has the potential to ameliorate SCD-associated neurocognitive changes and prevent neurocognitive progression. Further studies are required to determine if neurocognitive performance remains stable beyond 2 years post-HISCT.Clinical trial registration: The study was conducted under an investigator IND (14359) (MSC) and registered at clinicaltrials.gov (NCT01461837).

https://doi.org/10.1148/ryai.240076

Introduction. Erythropoietin (Epo) is a putative neuroprotective therapy that did not improve overall outcomes in a phase 3 randomized controlled trial for neonates with moderate or severe hypoxic-ischemic encephalopathy (HIE). However, HIE is a heterogeneous disorder, and it remains to be determined whether Epo had beneficial effects on a subset of perinatal brain injuries. Methods. This study was a secondary analysis of neuroimaging data from the High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, which was conducted from 2016 - 2021 at 17 sites involving 23 US academic medical centers. Participants were neonates >36 weeks' gestation undergoing therapeutic hypothermia for moderate or severe HIE who received 5 doses of study drug (Epoetin alpha 1000 U/kg/dose) or placebo in the first week of life. Treatment assignment was stratified by trial site and severity of encephalopathy. The primary outcome was the locus, pattern and acuity of brain injury as determined by three independent readers using a validated HIE Magnetic Resonance Imaging (MRI) scoring system. Results. Of the 500 infants enrolled in HEAL, 470 (94%) had high quality MRI data obtained at a median of 4.9 days of age (IQR 4.5 - 5.8). The incidence of injury to the deep grey nuclei, cortex, white matter, brainstem and cerebellum was similar between Epo and placebo groups. Likewise, the distribution of injury patterns was similar between groups. Among infants imaged at less than 8 days (n=414), 94 (23%) evidenced only acute, 93 (22%) only subacute and 89 (21%) both acute and subacute injuries, with similar distribution across treatment groups. Conclusion. Adjuvant erythropoietin did not reduce the incidence of regional brain injury. Subacute brain injury was more common than previously reported, which has key implications for the development of adjuvant neuroprotective therapies for this population.

White matter (WM) fiber tract differences are present in autism spectrum disorder (ASD) and could be important markers of behavior. One of the earliest phenotypic differences in ASD are language atypicalities. Although language has been linked to WM in typical development, no work has evaluated this association in early ASD. Participants came from the Infant Brain Imaging Study and included 321 infant siblings of children with ASD at high likelihood (HL) for developing ASD; 70 HL infants were later diagnosed with ASD (HL-ASD), and 251 HL infants were not diagnosed with ASD (HL-Neg). A control sample of 140 low likelihood infants not diagnosed with ASD (LL-Neg) were also included. Infants contributed expressive language, receptive language, and diffusion tensor imaging data at 6-, 12-, and 24 months. Mixed effects regression models were conducted to evaluate associations between WM and language trajectories. Trajectories of microstructural changes in the right arcuate fasciculus were associated with expressive language development. HL-ASD infants demonstrated a different developmental pattern compared to the HL-Neg and LL-Neg groups, wherein the HL-ASD group exhibited a positive association between WM fractional anisotropy and language whereas HL-Neg and LL-Neg groups showed weak or no association. No other fiber tracts demonstrated significant associations with language. In conclusion, results indicated arcuate fasciculus WM is linked to language in early toddlerhood for autistic toddlers, with the strongest associations emerging around 24 months. To our knowledge, this is the first study to evaluate associations between language and WM development during the pre-symptomatic period in ASD.

ObjectiveWe determined the frequency of previously unsuspected genetic or congenital anomalies in infants with HIE, and whether such anomalies are associated with neurodevelopmental outcome.MethodsInfants with moderate or severe HIE enrolled in a phase III randomized controlled trial (HEAL) underwent genetic testing when clinically indicated. Infants with known genetic or congenital anomalies were excluded. The primary outcome, i.e., death or neurodevelopmental impairment (NDI), was determined at two years of age by a standardized neurologic examination, Bayley Scales of Infant Development-III (BSID-III), and the Gross Motor Function Classification Scales. Secondary outcomes included cerebral palsy and BSID-III motor, cognitive and language scores at age 2 years.ResultsOf 500 infants with HIE, 24 (5%, 95% CI 3-7%) were diagnosed with a genetic (n=15) or congenital (n=14) anomaly. Infants with and without genetic or congenital anomalies had similar rates of severe encephalopathy and findings on neonatal EEG and brain MRI. However, infants with genetic or congenital anomalies were more likely to have the primary outcome of death or NDI (75% vs 50%, P= 0.02). Among survivors, those with a genetic or congenital anomaly were more likely to be diagnosed with cerebral palsy (32% vs. 13%, p =0.02), and had lower BSID-III scores in all three domains than HIE survivors without such anomalies.ConclusionAmong infants with HIE, 5% were diagnosed with a genetic or congenital anomaly. Despite similar clinical markers of HIE severity, infants with HIE and a genetic or congenital anomaly had worse neurodevelopmental outcomes than infants with HIE alone.