Children’s Institute

Alazami syndrome is a neurodevelopmental disorder characterized by postnatal growth retardation, moderate to severe intellectual disability, and facial dysmorphology. It is caused by biallelic variants in the transcriptional regulator La ribonucleoprotein 7 (LARP7), where frameshift variants accounted for the majority of cases. The current study presents 7 new patients, including 3 males and 4 females from 3 unrelated families. Careful and thorough clinical examination identified novel oro-dental disease abnormalities, including a prominent premaxilla and enamel defects. The detected variants (c.1113_1116del, c.997 + 2T > C and c.518T > C) were not reported in the previous studies. The substitution c.518T > C represented the second missense variant to be identified in patients with Alazami syndrome. Male patients from the three families fulfilled ≥ 2 clinical warning signs of primary immunodeficiency. Lymphocyte subset counts and immunoglobulin levels were estimated in patients from two families. The values were within reference ranges, with only minor non-significant alterations in cytotoxic T-cell counts. A functional assay of B lymphocyte response was performed in one family, demonstrating impaired Streptococcus pneumoniae IgG antibody production following Pneumovax vaccination in the male patient, while his female sibling mounted an adequate response. In conclusion, the disease has a wide range of symptoms, which vary greatly among the affected patients. Our study expanded the clinical and molecular spectrum of the disorder and highlighted immunodeficiency as an underrecognized disease feature, potentially with a male sex predilection.

The planning of sample size for research studies often focuses on obtaining a significant result given a specified level of power, significance, and an anticipated effect size. This planning requires prior knowledge of the study design and a statistical analysis to calculate the proposed sample size. However, there may not be one specific testable analysis from which to derive power (Silberzahn et al., Advances in Methods and Practices in Psychological Science, 1(3), 337356, 2018) or a hypothesis to test for the project (e.g., creation of a stimuli database). Modern power and sample size planning suggestions include accuracy in parameter estimation (AIPE, Kelley, Behavior Research Methods, 39(4), 755–766, 2007; Maxell et al., Annual Review of Psychology, 59, 537–563, 2008) and simulation of proposed analyses (Chalmers & Adkins, The Quantitative Methods for Psychology, 16(4), 248–280, 2020). These toolkits offer flexibility in traditional power analyses that focus on the if-this, then-that approach. However, both AIPE and simulation require either a specific parameter (e.g., mean, effect size, etc.) or a statistical test for planning sample size. In this tutorial, we explore how AIPE and simulation approaches can be combined to accommodate studies that may not have a specific hypothesis test or wish to account for the potential of a multiverse of analyses. Specifically, we focus on studies that use multiple items and suggest that sample sizes can be planned to measure those items adequately and precisely, regardless of the statistical test. This tutorial also provides multiple code vignettes and package functionality that researchers can adapt and apply to their own measures.

Abstract Voltage-gated (Kv) potassium channels are critical for neuronal physiology, and their dysfunction can lead to serious consequences. For example, mutations in the silent modulatory Kv8.2 subunit are known to cause irreversible inherited blindness ( KCNV2 retinopathy). This is a currently incurable condition that causes lifelong visual loss, reduced visual acuity, photoaversion, night blindness and abnormal colour vision, alongside a distinctive supernormal electrophysiological (ERG) retinal response to light. In this study, we demonstrate that AAV-mediated gene replacement therapy delivering a codon-optimised human KCNV2 gene subretinally into Kv8.2 knock-out mice significantly restores retinal function. Treated mice exhibited improved ERG responses and correct expression of KCNV2 and its encoded Kv8.2 protein in photoreceptors. Recovery of visually guided scotopic and photopic optomotor responses to wildtype levels was achieved at lower vector doses, highlighting dose-dependent efficacy. Furthermore, treatment of human retinal organoids derived from a KCNV2 patient iPSC line resulted in substantial Kv8.2 protein rescue. This work provides the first preclinical proof-of-concept for the safety and therapeutic potential of gene therapy for KCNV2 retinopathy, laying a strong foundation for future clinical trials.

SLC30A9 mutations are linked to Birk-Landau-Perez syndrome, which is characterized by neurodevelopmental and renal disease, thought to result from impaired zinc homeostasis. In this report, we describe a patient with a homozygous likely pathogenic SLC30A9 variant with atypical chorio-retinal degeneration, suggesting retinal involvement in SLC30A9-associated diseases. The patient has bilateral sensorineural hearing loss, developmental delay, intellectual disability, abnormal balance, and Tourette syndrome. Ophthalmic manifestations include vascular attenuation, optic disc pallor, and pigmentation. In addition, the patient is noted to have high myopia. Our case highlights the importance of broad genetic testing in diagnosing rare multi-systemic disorders. Further research into the molecular mechanisms by which SLC30A9 results in photoreceptor disease is essential to understand its role in retinal degeneration and to develop potential therapeutic strategies.

Background: Adolescents with moderate and severe congenital heart disease (CHD) experience considerable risk of mental health comorbidities. Youth with CHD have 5-7 times greater odds of anxiety or depression than children without CHD. Psychological health is important to cardiac health, but there have been few CHD-specific psychological interventions. This PHN study will evaluate the effectiveness of a resilience and well-being-focused telemedicine intervention in adolescents with CHD and provide one of the largest linkages of self-reported psychosocial data with cardiac clinical outcomes. Research Questions: The WE BEAT CHD Study aims to: 1) evaluate the effectiveness of the 5-week WE BEAT telemedicine intervention compared to usual care on self-reported resiliency and psychosocial outcomes including depression, anxiety, and quality of life, 2) determine associations between psychosocial survey data and cardiac outcomes including composite event score, heart failure, and metabolic health, and 3) establish a biorepository to associate psychosocial data with stress-related biomarkers, including stress cortisol, inflammatory biomarkers, and epigenetic aging. Approach: In this 2-arm, 2-staged stratified randomized, parallel, multi-center pragmatic trial (Figure 1), we seek to recruit 390 English or Spanish speaking 12-17-year-olds with moderately or severely complex CHD across ~15 PHN core and auxiliary sites. The intervention arm will include 300 participants and half will be randomized to complete a booster session. Study design was informed by a successful pilot study, patient/family input, and pragmatic clinical trial design. Five 45-minute intervention sessions and study surveys completed at baseline, 5, 18 and 30 weeks will be done remotely via video conferencing and a study mobile app. Home collection of biospecimen samples will be available. Study duration is estimated to be 5 years. Results: The primary outcome will be change in participant self-reported resiliency as measured by the Connor-Davidson Resilience Scale© from baseline to Week 5, with secondary endpoints of change in resiliency from baseline to Weeks 18 and 30. Conclusion: This study addresses the need for promotive mental-health-focused interventions for adolescents with CHD. The pragmatic trial design intends to bolster successful recruitment and ease of translation to clinical practice. Secondary aims position the trial for mechanistic investigations and future ancillary studies.

Abstract SCN2A variants are one of the most common genetic causes of intractable epilepsy in children, particularly in developmental and epileptic encephalopathies (DEEs) which can present with uncontrolled seizures at birth, accounting for 1-2% of all epileptic encephalopathies. There is significant genotype-phenotype heterogeneity in SCN2A-related disorders (SRD) which include neurologic symptoms of seizures, developmental delay, choreoathetosis, and autism spectrum disorder (ASD). A substantial fraction of causal variants is gain-of-functon(GOF) or mixed function, functionally associated with increased open-probability or greater sodium current flux. Individualized allele-selective antisense oligonucleotides (ASOs) were designed to target heterozygous intronic SNPs for decreased expression of mutant SCN2A transcript while preserving the wild-type copy. Efficacy measures were also individualized to phenotype. Improvements in seizure control, development, and quality-of-life were seen with no ASO-related adverse events. Haplotype phasing in a separate cohort of infants with SRD diagnosed by rapid whole genome sequencing identified 16% of patients with compatible SNPs. Allele-selective ASOs demonstrate potential to decrease seizures and impact neurodevelopment, providing a pathway for potential benefit in n-of-1 to n-of-more SRD patients.

Abstract Cancer cells evolve to increase fitness and evade the immune system, but it is not clear if tumor infiltrating lymphocytes (TILs) undergo selection for somatic mutations that augment anti-cancer immunity. Using single molecule whole exome sequencing in TILs, we identified somatic mutations in Tyrosine-protein kinase 2 ( TYK2 ), several of which increased TYK2 phosphorylation, JAK-STAT signaling, and interferon gamma signaling. Among these mutations, TYK2 D810V was recurrently observed in patients with diverse cancer types. In vitro, TYK2 D810V enhanced T cells effector functions and cytokine production. We generated mice with a germline Tyk2 D807V mutation that recapitulated the human TYK2 D810V mutation. These mice were healthy and did not develop autoimmune disorders. However, they possessed enhanced anti-tumor effects in the context of syngeneic and autochthonous cancer models. Adoptive therapy with Tyk2 D807V CD8⁺ T cells also decreased cancer growth. Thus, naturally occurring mutations in non-malignant lymphocytes can antagonize cancer and inspire new immunotherapies strategies.

BackgroundThe COVID-19 pandemic magnified longstanding racial and ethnic disparities in pediatric health, but it is unclear which populations experienced the largest disparities. Our objective was to determine whether disparities in COVID-19 severity differed with respect to patient factors analyzed as effect modifiers.MethodsUsing data from the Premier Healthcare Database, this retrospective cohort study included encounters among inpatients < 19 years old from April 2020 through September 2022 in the USA with a COVID-19 diagnosis. Outcomes of COVID-19 severity were intensive care unit (ICU) admission and ventilator use. Comparisons between Black and White patients and Hispanic and White patients were adjusted for confounders using propensity score weights, reported as risk differences (RDs) in percentage points, and tested for heterogeneity (interaction P) across subgroups of effect modifiers such as complex chronic conditions (CCCs) and insurance status.ResultsOf 8947 pediatric inpatients with primary COVID-19 diagnosis, 3858 were White, 2153 were Black, and 2936 were Hispanic. Among children with a CCC, 14.3% of Black inpatients required a ventilator compared to 9.8% of White inpatients; among children without a CCC, 3.2% of both Black and White inpatients required a ventilator (RDs 4.5 vs 0.0; interaction P = .013). Comparisons of Hispanic and White inpatients showed a similar trend in ventilator use, with larger disparities among inpatients with CCCs and no difference among those without CCCs (RDs 2.7 vs −0.7; interaction P=.031). Among children with government insurance, 25.9% of Black inpatients were admitted to the ICU compared to 20.8% of White inpatients; among children with private insurance, Black and White inpatients had comparable ICU admission rates of 20.0% and 21.4%, respectively (RDs 5.1 vs −1.4; interaction P = .025).ConclusionsAmong hospitalized children, racial and ethnic disparities in COVID-19 severity were largest for those with CCCs or government insurance. These results can help identify target populations for interventions to reduce inequity.

Septic encephalopathy (SE) is a severe complication of sepsis, characterized by neuroinflammation and metabolic dysfunction, with the cerebellum among the most vulnerable brain regions. Advances in the field have been constrained by the lack of reliable biomarkers for SE detection, incomplete mapping of cerebellar metabolic alterations in SE, and limited insight into the therapeutic mechanisms of human mesenchymal stem cell (MSC)-derived small extracellular vesicle (sEV) therapy. To overcome these challenges, we used a murine sepsis model and conducted integrated metabolomic analyses of cerebellar tissue and plasma, with and without MSC-sEV administration. Cross-compartment analyses identified six plasma metabolites with strong diagnostic potential in mice, three of which (n-acetylputrescine, aspartic acid, and cystathionine) were also observed in the plasma of human septic patients, supporting their promise as translatable biomarker candidates. Sepsis triggered profound cerebellar metabolic dysfunction, suppression of oxidative energy metabolism, and redox imbalance. MSC-sEVs attenuated these disturbances via their bioactive cargo, restoring cellular energetics and reestablishing antioxidant balance. Collectively, these results highlight cross-species plasma biomarkers for SE diagnosis, delineate key cerebellar metabolic mechanisms in SE, and demonstrate therapeutic modulation by human MSC-sEVs.