AXIN1 mutations in nonsyndromic craniosynostosis.

OBJECTIVE: Occurring once in every 2000 live births, craniosynostosis (CS) is the most frequent cranial birth defect. Although the genetic etiologies of syndromic CS cases are well defined, the genetic cause of most nonsyndromic cases remains unknown. METHODS: The authors analyzed exome or RNA sequencing data from 876 children with nonsyndromic CS, including 291 case-parent trios and 585 additional probands. The authors also utilized the GeneMatcher platform and the Gabriella Miller Kids First genome sequencing project to identify additional CS patients with AXIN1 mutations. RESULTS: The authors describe 11 patients with nonsyndromic CS harboring rare, damaging mutations in AXIN1, an inhibitor of Wnt signaling. AXIN1 regulates signaling upstream of key mediators of osteoblast differentiation. Three of the 6 mutations identified in trios occurred de novo in the proband, while 3 were transmitted from unaffected parents. Patients with nonsyndromic CS were highly enriched for mutations in AXIN1 compared to both expectation (p = 0.0008) and exome sequencing data from > 76,000 healthy controls (p = 2.3 × 10-6), surpassing the thresholds for genome-wide significance. CONCLUSIONS: These findings describe the first phenotype associated with mutations in AXIN1, with mutations identified in approximately 1% of nonsyndromic CS cases. The results strengthen the existing link between Wnt signaling and maintenance of cranial suture patency and have implications for genetic testing in families with CS.

Satisfaction with mode of delivery of genomic sequencing results in a diverse national sample of research participants through the Clinical Sequencing Evidence-Generating Research Consortium.

PURPOSE: Research that includes diverse patient populations is necessary to optimize implementation of telehealth. METHODS: As part of a Clinical Sequencing Evidence-Generating Research Consortium cross-site study, we assessed satisfaction with mode of return of results (RoR) delivery across a diverse sample of participants receiving genetic testing results in person vs telemedicine (TM). RESULTS: Ninety-eight percent of participants were satisfied with their mode of results delivery. Participants receiving results by TM were more likely to report a preference for receiving results in a different way and challenges with providers noticing difficulties with understanding. More than 90% reported satisfaction across all items measuring support and interaction during sessions. Participants self-reporting Hispanic/Latino or Black/African American race and ethnicity compared with White/European American, fewer years of education, and having lower health literacy were more likely to report challenges with understanding the information or asking questions. Participants who were White/European American, had more years of education, and higher health literacy reported higher communication scores, reflecting more positive evaluations of the communication experience. CONCLUSION: TM is an acceptable mode of return of results delivery across diverse settings and populations. Research optimizing approaches for underrepresented populations, populations with lower levels of education and health literacy, and multilingual populations is necessary.

Diagnostic yield after next-generation sequencing in pediatric cardiovascular disease.

Genetic testing with exome sequencing and genome sequencing is increasingly offered to infants and children with cardiovascular diseases. However, the rates of positive diagnoses after genetic testing within the different categories of cardiac disease and phenotypic subtypes of congenital heart disease (CHD) have been little studied. We report the diagnostic yield after next-generation sequencing in 500 patients with CHD from diverse population subgroups that were enrolled at three different sites in the Clinical Sequencing Evidence-Generating Research consortium. Patients were ascertained due to a primary cardiovascular issue comprising arrhythmia, cardiomyopathy, and/or CHD, and corresponding human phenotype ontology terms were selected to describe the cardiac and extracardiac findings. We examined the diagnostic yield for patients with arrhythmia, cardiomyopathy, and/or CHD and phenotypic subtypes of CHD comprising conotruncal defects, heterotaxy, left ventricular outflow tract obstruction, septal defects, and "other" heart defects. We found a significant increase in the frequency of positive findings for patients who underwent genome sequencing compared to exome sequencing and for syndromic cardiac defects compared to isolated cardiac defects. We also found significantly higher diagnostic rates for patients who presented with isolated cardiomyopathy compared to isolated CHD. For patients with syndromic presentations who underwent genome sequencing, there were significant differences in the numbers of positive diagnoses for phenotypic subcategories of CHD, ranging from 31.7% for septal defects to 60% for "other". Despite variation in the diagnostic yield at each site, our results support genetic testing in pediatric patients with syndromic and isolated cardiovascular issues and in all subtypes of CHD.

Biallelic OTUD6B variants associated with a Kabuki syndrome-like disorder in three siblings: A clinical report and literature review.

Biallelic variants in the OTUD6B gene have been reported in the literature in association with an intellectual developmental disorder featuring dysmorphic facies, seizures, and distal limb abnormalities. Physical differences described for affected individuals suggest that the disorder may be clinically recognizable, but previous publications have reported an initial clinical suspicion for Kabuki syndrome (KS) in some affected individuals. Here, we report on three siblings with biallelic variants in OTUD6B co-segregating with neurodevelopmental delay, shared physical differences, and other clinical findings similar to those of previously reported individuals. However, clinical manifestations such as long palpebral fissures, prominent and cupped ears, developmental delay, growth deficiency, persistent fetal fingertip pads, vertebral anomaly, and seizures in the proband were initially suggestive of KS. In addition, previously unreported clinical manifestations such as delayed eruption of primary dentition, soft doughy skin with reduced sweating, and mirror movements present in our patients suggest an expansion of the phenotype, and we perform a literature review to update on current information related to OTUD6B and human gene-disease association.

De novo variants predicting haploinsufficiency for DIP2C are associated with expressive speech delay.

The disconnected (disco)-interacting protein 2 (DIP2) gene was first identified in D. melanogaster and contains a DNA methyltransferase-associated protein 1 (DMAP1) binding domain, Acyl-CoA synthetase domain and AMP-binding sites. DIP2 regulates axonal bifurcation of the mushroom body neurons in D. melanogaster and is required for axonal regeneration in the neurons of C. elegans. The DIP2 homologues in vertebrates, Disco-interacting protein 2 homolog A (DIP2A), Disco-interacting protein 2 homolog B (DIP2B), and Disco-interacting protein 2 homolog C (DIP2C), are highly conserved and expressed widely in the central nervous system. Although there is evidence that DIP2C plays a role in cognition, reports of pathogenic variants in these genes are rare and their significance is uncertain. We present 23 individuals with heterozygous DIP2C variants, all manifesting developmental delays that primarily affect expressive language and speech articulation. Eight patients had de novo variants predicting loss-of-function in the DIP2C gene, two patients had de novo missense variants, three had paternally inherited loss of function variants and six had maternally inherited loss-of-function variants, while inheritance was unknown for four variants. Four patients had cardiac defects (hypertrophic cardiomyopathy, atrial septal defects, and bicuspid aortic valve). Minor facial anomalies were inconsistent but included a high anterior hairline with a long forehead, broad nasal tip, and ear anomalies. Brainspan analysis showed elevated DIP2C expression in the human neocortex at 10-24 weeks after conception. With the cases presented herein, we provide phenotypic and genotypic data supporting the association between loss-of-function variants in DIP2C with a neurocognitive phenotype.

Genetic ancestry and diagnostic yield of exome sequencing in a diverse population.

It has been suggested that diagnostic yield (DY) from Exome Sequencing (ES) may be lower among patients with non-European ancestries than those with European ancestry. We examined the association of DY with estimated continental/subcontinental genetic ancestry in a racially/ethnically diverse pediatric and prenatal clinical cohort. Cases (N = 845) with suspected genetic disorders underwent ES for diagnosis. Continental/subcontinental genetic ancestry proportions were estimated from the ES data. We compared the distribution of genetic ancestries in positive, negative, and inconclusive cases by Kolmogorov-Smirnov tests and linear associations of ancestry with DY by Cochran-Armitage trend tests. We observed no reduction in overall DY associated with any genetic ancestry (African, Native American, East Asian, European, Middle Eastern, South Asian). However, we observed a relative increase in proportion of autosomal recessive homozygous inheritance versus other inheritance patterns associated with Middle Eastern and South Asian ancestry, due to consanguinity. In this empirical study of ES for undiagnosed pediatric and prenatal genetic conditions, genetic ancestry was not associated with the likelihood of a positive diagnosis, supporting the equitable use of ES in diagnosis of previously undiagnosed but potentially Mendelian disorders across all ancestral populations.

Embracing the Science of Motherhood: Pregnancy's Transformative Effects on the Central Nervous System and the Radiance of Maternal Hormones and Immune Responses.

Pregnancy is often thought of as a time of happiness and anticipation, however, for some women, it can bring about significant emotional distress and feelings of vulnerability. The physiological changes that occur during pregnancy, including hormonal fluctuations and alterations to the immune and physical systems, can affect various parts of the body, including the central nervous system (CNS). As a result, existing conditions may be intensified or new ones, such as neurologic or psychiatric disorders, may arise, exposing women to increased risk of life-threatening conditions or suicide, in the worst-case scenarios. Given the impact of pregnancy on CNS diseases, it is crucial for healthcare providers and patients alike to be aware of these potential effects. By understanding how pregnancy may affect the CNS, clinicians can take appropriate steps to ensure that women receive the care and support they need to minimize any negative outcomes for both the mother and the baby. This paper aims to review the available evidence on the impact of pregnancy on CNS diseases, including mental health conditions, from both the clinical and biomolecular perspectives. By illuminating this crucial subject, this study fosters a delicate understanding within both patients and healthcare providers, thereby paving the way for enhanced outcomes for women throughout their pregnancy journey and beyond.

Genetics in Pediatric Practice: From Baby Steps to Running Fast.

In the last few decades, medical genetics has undergone a revolution because of the development of technologies and informatics approaches that can generate and analyze large amounts of genomic data. Pediatricians have been hugely affected by these changes. The early age of presentation for birth defects and neurocognitive disorders, together with a shortage of trained genetics professionals, has increased consultations for conditions with a genetic cause, not only in pediatric practice but also in other subspecialties. In the future, genetic testing in childhood is likely to include pediatricians, who can initiate testing in partnership with trained genetics professionals.

Parent-Reported Clinical Utility of Pediatric Genomic Sequencing.

BACKGROUND AND OBJECTIVES: Genomic sequencing (GS) is increasingly used for diagnostic evaluation, yet follow-up care is not well understood. We assessed clinicians' recommendations after GS, parent-reported follow-up, and actions parents initiated in response to learning their child's GS results. METHODS: We surveyed parents of children who received GS through the Clinical Sequencing Evidence Generating Research consortium ∼5 to 7 months after return of results. We compared the proportion of parents who reported discussing their child's result with a clinician, clinicians' recommendations, and parents' follow-up actions by GS result type using χ2 tests. RESULTS: A total of 1188 respondents completed survey measures on recommended medical actions (n = 1187) and/or parent-initiated actions (n = 913). Most parents who completed recommended medical actions questions (n = 833, 70.3%) reported having discussed their child's GS results with clinicians. Clinicians made recommendations to change current care for patients with positive GS results (n = 79, 39.1%) more frequently than for those with inconclusive (n = 31, 12.4%) or negative results (n = 44, 11.9%; P < .001). Many parents discussed (n = 152 completed, n = 135 planned) implications of GS results for future pregnancies with a clinician. Aside from clinical recommendations, 13.0% (n = 119) of parents initiated changes to their child's health or lifestyle. CONCLUSIONS: In diverse pediatric clinical contexts, GS results can lead to recommendations for follow-up care, but they likely do not prompt large increases in the quantity of care received.

Behavioral and neuropsychiatric challenges across the lifespan in individuals with Rubinstein-Taybi syndrome.

Introduction: Rubinstein-Taybi syndrome (RSTS) is a rare congenital disorder characterized by developmental and intellectual disability, broadening of thumbs and halluces, and characteristic facial features. Pathogenic variants in CREBBP lead to RSTS type 1 (RSTS1) and in EP300 lead to RSTS type 2 (RSTS2). Individuals with RSTS can demonstrate a variety of behavioral and neuropsychiatric challenges, including anxiety, hyperactivity/inattention, self-injury, repetitive behaviors, and aggression. Behavioral challenges are consistently reported as one of the primary factors impacting quality of life. Despite the high prevalence and morbidity of behavioral and neuropsychiatric features of RSTS, a paucity of data exists regarding its natural history. Methods: To better understand the neurocognitive and behavioral challenges faced by individuals with RSTS, 71 caregivers of individuals with RSTS, ranging in age from one to 61 years, completed four questionnaires measuring obsessive compulsive disorder (OCD)-like symptoms, anxiety, challenging behaviors, and adaptive behavior and living skills. Results: Results revealed a high prevalence of neuropsychiatric and behavioral challenges across ages. We found specific challenging behaviors were worse in school age individuals. Scaled adaptive behavior and living skill scores differed across ages with an increased gap between typically developing peers becoming more apparent at older ages. Between types, individuals with RSTS2 had better adaptive behavior and living skills and less stereotypic behaviors but higher social phobia than individuals with RSTS1. Further, female individuals with RSTS1 appear to have increased hyperactivity. However, both groups had impairments in adaptive functioning compared to typically developing peers. Discussion: Our findings support and expand previous reports of a high prevalence of neuropsychiatric and behavioral challenges in individuals with RSTS. However, we are the first to report differences between types of RSTS. Further, age-related differences were seen with higher challenging behaviors within school-age individuals, which may improve over time, and lower adaptive behavioral skills compared to normative scales. Anticipation of these potential differential challenges across age is vital for proactive management for individuals with RSTS. Our study underscores the importance of enacting neuropsychiatric and behavioral screening earlier in childhood so appropriate management can be implemented. However, further longitudinal studies in larger cohorts are needed to understand better how behavioral and neuropsychiatric characteristics of RSTS evolve over the lifespan and differentially affect subpopulation groups.

Diagnostic Yield of Exome Sequencing in a Diverse Pediatric and Prenatal Population is not Associated with Genetic Ancestry.

Purpose: It has been hypothesized that diagnostic yield (DY) from Exome Sequencing (ES) may be lower among patients with non-European ancestries than those with European ancestry. We examined the association of DY with estimated continental genetic ancestry in a racially/ethnically diverse pediatric and prenatal clinical cohort. Methods: Cases (N=845) with suspected genetic disorders underwent ES for diagnosis. Continental genetic ancestry proportions were estimated from the ES data. We compared the distribution of genetic ancestries in positive, negative, and inconclusive cases by Kolmogorov Smirnov tests and linear associations of ancestry with DY by Cochran-Armitage trend tests. Results: We observed no reduction in overall DY associated with any continental genetic ancestry (Africa, America, East Asia, Europe, Middle East, South Asia). However, we observed a relative increase in proportion of autosomal recessive homozygous inheritance versus other inheritance patterns associated with Middle Eastern and South Asian ancestry, due to consanguinity. Conclusions: In this empirical study of ES for undiagnosed pediatric and prenatal genetic conditions, genetic ancestry was not associated with the likelihood of a positive diagnosis, supporting the ethical and equitable use of ES in diagnosis of previously undiagnosed but potentially Mendelian disorders across all ancestral populations.

Monoallelic loss-of-function BMP2 variants result in BMP2-related skeletal dysplasia spectrum.

PURPOSE: Bone morphogenic proteins (BMPs) regulate gene expression that is related to many critical developmental processes, including osteogenesis for which they are named. In addition, BMP2 is widely expressed in cells of mesenchymal origin, including bone, cartilage, skeletal and cardiac muscle, and adipose tissue. It also participates in neurodevelopment by inducing differentiation of neural stem cells. In humans, BMP2 variants result in a multiple congenital anomaly syndrome through a haploinsufficiency mechanism. We sought to expand the phenotypic spectrum and highlight phenotypes of patients harboring monoallelic missense variants in BMP2. METHODS: We used retrospective chart review to examine phenotypes from an international cohort of 18 individuals and compared these with published cases. Patient-derived missense variants were modeled in zebrafish to examine their effect on the ability of bmp2b to promote embryonic ventralization. RESULTS: The presented cases recapitulated existing descriptions of BMP2-related disorders, including craniofacial, cardiac, and skeletal anomalies and exhibit a wide phenotypic spectrum. We also identified patients with neural tube defects, structural brain anomalies, and endocrinopathies. Missense variants modeled in zebrafish resulted in loss of protein function. CONCLUSION: We use this expansion of reported phenotypes to suggest multidisciplinary medical monitoring and management of patients with BMP2-related skeletal dysplasia spectrum.

Diagnostic yield of pediatric and prenatal exome sequencing in a diverse population.

The diagnostic yield of exome sequencing (ES) has primarily been evaluated in individuals of European ancestry, with less focus on underrepresented minority (URM) and underserved (US) patients. We evaluated the diagnostic yield of ES in a cohort of predominantly US and URM pediatric and prenatal patients suspected to have a genetic disorder. Eligible pediatric patients had multiple congenital anomalies and/or neurocognitive disabilities and prenatal patients had one or more structural anomalies, disorders of fetal growth, or fetal effusions. URM and US patients were prioritized for enrollment and underwent ES at a single academic center. We identified definitive positive or probable positive results in 201/845 (23.8%) patients, with a significantly higher diagnostic rate in pediatric (26.7%) compared to prenatal patients (19.0%) (P = 0.01). For both pediatric and prenatal patients, the diagnostic yield and frequency of inconclusive findings did not differ significantly between URM and non-URM patients or between patients with US status and those without US status. Our results demonstrate a similar diagnostic yield of ES between prenatal and pediatric URM/US patients and non-URM/US patients for positive and inconclusive results. These data support the use of ES to identify clinically relevant variants in patients from diverse populations.