Low-level mosaic GCK mutations in children with diazoxide-unresponsive congenital hyperinsulinism.

CONTEXT: Some children with diazoxide-unresponsive congenital hyperinsulinism (HI) lack any detectable disease-causing mutation in peripheral blood DNA. OBJECTIVE: To examine whether somatic post-zygotic mutations of known HI genes are responsible for disease in children with diazoxide-unresponsive HI requiring surgery with histology not classified as focal or Localized Islet Nuclear Enlargement (LINE), and without detectable mutations by standard genetic testing of peripheral blood DNA. METHODS: Next-generation sequencing (NGS) was performed on specimens of pancreas from 10 children with diazoxide-unresponsive HI. RESULTS: Four unique GCK mutations were identified at low levels of mosaicism ranging from 4.4-10.1% in pancreatic DNA from five of these 10 children. The GCK mutations were not detectable in peripheral blood DNA by NGS in three cases from which peripheral blood DNA was available for testing. All four GCK mutations have been previously published as activating HI mutations. The histology was consistent with diffuse-HI in four of the five cases with mosaic GCK mutations. In one of these, hypomethylation of IC2 on chromosome 11p was identified in pancreatic and peripheral blood DNA. Histology of the fifth case revealed minor islet abnormalities suggestive of Beckwith Wiedemann Spectrum (BWSp) although molecular analysis for 11pUPD was negative in pancreas. CONCLUSION: These results indicate that post-zygotic somatic GCK mutations are responsible for some cases of non-focal diazoxide-unresponsive hyperinsulinism.

A novel pathogenic germline chromosome 3 inversion in von Hippel-Lindau disease.

von Hippel-Lindau (VHL) is an autosomal-dominant hereditary tumour susceptibility disease associated with pathogenic germline variants in the VHL tumour suppressor gene. VHL patients are at increased risk of developing multiple benign and malignant tumours. Current CLIA-based genetic tests demonstrate a very high detection rate of germline VHL variants in patients with clinical manifestations of VHL. In this report, we describe a large family with canonical VHL manifestations, for which no germline alteration had been detected by conventional germline testing. We identified a novel 291 kb chromosomal inversion involving chromosome 3p in affected family members. This inversion disrupts the VHL gene between exon 2 and exon 3 and is thereby responsible for the disease observed in this family.

Elucidating disparities in sunscreen coverage among state Medicaid preferred drug lists.

Regular application of over-the-counter (OTC) sunscreen is considered the foundation of skin cancer prevention, yet OTC sunscreen is not eligible for reimbursement in almost all state Medicaid benefit plans. On review of 111 Medicaid preferred drug lists (PDLs) across 50 states and the District of Columbia (DC), only five plans were identified that incorporate coverage of sunscreen. Thus, many recipients of Medicaid, the majority of whom are individuals and families of lower socioeconomic status, may encounter financial difficulty and thus forego utilizing sun protective measures due to financial constraints. Here, we compare current Medicaid coverage of OTC sunscreen and discuss calculated and theoretical annual costs of this skin cancer prevention method.

Somatic RAP1B gain-of-function variant underlies isolated thrombocytopenia and immunodeficiency.

The ubiquitously expressed small GTPase Ras-related protein 1B (RAP1B) acts as a molecular switch that regulates cell signaling, cytoskeletal remodeling, and cell trafficking and activates integrins in platelets and lymphocytes. The residue G12 in the P-loop is required for the RAP1B-GTPase conformational switch. Heterozygous germline RAP1B variants have been described in patients with syndromic thrombocytopenia. However, the causality and pathophysiological impact remained unexplored. We report a boy with neonatal thrombocytopenia, combined immunodeficiency, neutropenia, and monocytopenia caused by a heterozygous de novo single nucleotide substitution, c.35G>A (p.G12E) in RAP1B. We demonstrate that G12E and the previously described G12V and G60R were gain-of-function variants that increased RAP1B activation, talin recruitment, and integrin activation, thereby modifying late responses such as platelet activation, T cell proliferation, and migration. We show that in our patient, G12E was a somatic variant whose allele frequency decreased over time in the peripheral immune compartment, but remained stable in bone marrow cells, suggesting a differential effect in distinct cell populations. Allogeneic hematopoietic stem cell transplantation fully restored the patient's hemato-immunological phenotype. Our findings define monoallelic RAP1B gain-of-function variants as a cause for constitutive immunodeficiency and thrombocytopenia. The phenotypic spectrum ranged from isolated hematological manifestations in our patient with somatic mosaicism to complex syndromic features in patients with reported germline RAP1B variants.

Proteogenomic analysis integrated with electronic health records data reveals disease-associated variants in Black Americans.

BACKGROUND: Most genome wide association studies (GWAS) of plasma proteomics have focused on White individuals of European ancestry, limiting biological insight from other ancestry enriched protein quantitative loci (pQTL). METHODS: We conducted a discovery GWAS of ~3,000 plasma proteins measured by the antibody based Olink platform in 1,054 Black adults from the Jackson Heart Study (JHS), and validated our findings in the Multi-Ethnic Study of Atherosclerosis (MESA). The genetic architecture of identified pQTLs were further explored through fine mapping and admixture association analysis. Finally, using our pQTL findings, we performed a phenome wide association study (PheWAS) across two large multi-ethnic electronic health record (EHR) systems in All of Us and BioMe. RESULTS: We identified 1002 pQTLs for 925 proteins. Fine mapping and admixture analyses suggested allelic heterogeneity of the plasma proteome across diverse populations. We identified associations for variants enriched in African ancestry, many in diseases that lack precise biomarkers, including cis-pQTLs for Cathepsin L (CTSL) and Siglec-9 that were linked with sarcoidosis and non-Hodgkin's lymphoma, respectively. We found concordant associations across clinical diagnoses and laboratory measurements, elucidating disease pathways, including a cis-pQTL associated with circulating CD58, white blood cell count, and multiple sclerosis. CONCLUSIONS: Our findings emphasize the value of leveraging diverse populations to enhance biological insights from proteomics GWAS, and we have made this resource readily available as an interactive web portal.

Development of mRNA Lipid Nanoparticles: Targeting and Therapeutic Aspects.

Lipid nanoparticles (LNPs) have emerged as leading non-viral carriers for messenger RNA (mRNA) delivery in clinical applications. Overcoming challenges in safe and effective mRNA delivery to target tissues and cells, along with controlling release from the delivery vehicle, remains pivotal in mRNA-based therapies. This review elucidates the structure of LNPs, the mechanism for mRNA delivery, and the targeted delivery of LNPs to various cells and tissues, including leukocytes, T-cells, dendritic cells, Kupffer cells, hepatic endothelial cells, and hepatic and extrahepatic tissues. Here, we discuss the applications of mRNA-LNP vaccines for the prevention of infectious diseases and for the treatment of cancer and various genetic diseases. Although challenges remain in terms of delivery efficiency, specific tissue targeting, toxicity, and storage stability, mRNA-LNP technology holds extensive potential for the treatment of diseases.

Congenital Erythropoietic Porphyria: A Case of Hepatic Failure and Angioedema Following Ferrous Sulfate Supplementation.

This report describes an unusual case of a young anemic female who experienced acute hepatic insufficiency and angioedema after ferrous sulfate consumption. Her primary diagnosis of congenital erythropoietic porphyria (CEP) was revealed after a detailed dermatologic examination and laboratory data. The patient was treated with IV methylprednisolone along with red blood cell transfusion, vitamin supplementation, and wound care. Our case report emphasizes the importance of physician awareness of CEP since it is a rare disease that tends to mimic other chronic porphyrias, various drug reactions, and collagenopathies.

Genetic profiling and diagnostic strategies for patients with ectodermal dysplasias in Korea.

BACKGROUND: Ectodermal dysplasia (ED) is a rare genetic disorder that affects structures derived from the ectodermal germ layer. RESULTS: In this study, we analyzed the genetic profiles of 27 Korean patients with ED. Whole exome sequencing (WES) was performed on 23 patients, and targeted panel sequencing was conducted on the remaining 4 patients. Among the patients in the cohort, 74.1% (20/27) tested positive for ED. Of these positive cases, EDA and EDAR mutations were found in 80% (16/20). Notably, 23.1% (3/13) of EDA-positive cases exhibited copy number variations. Among the 23 patients who underwent WES, we conducted a virtual panel analysis of eight well-known genes, resulting in diagnoses for 56.5% (13/23) of the cases. Additionally, further analysis of approximately 5,000 OMIM genes identified four more cases, increasing the overall positivity rate by approximately 17%. These findings underscore the potential of WES for improving the diagnostic yield of ED. Remarkably, 94.1% of the patients manifesting the complete triad of ED symptoms (hair/skin/dental) displayed detectable EDA/EDAR mutations. In contrast, none of the 7 patients without these three symptoms exhibited EDA/EDAR mutations. CONCLUSIONS: When conducting molecular diagnostics for ED, opting for targeted sequencing of EDA/EDAR mutations is advisable for cases with classical symptoms, while WES is deemed an effective strategy for cases in which these symptoms are absent.

Facial Sebaceous Hyperplasia in an Adolescent With Hypohidrotic Ectodermal Dysplasia.

We report on a 13-year-old boy diagnosed with hypohidrotic ectodermal dysplasia (HED) due to a pathogenic variant in ectodysplasin A (EDA). He exhibited multiple whitish, millimetric papules clustered on the nasal ala, forehead, temporal, and zygomatic arch areas. Histological examination revealed numerous hyperplastic sebaceous lobules within the upper dermis. The occurrence of sebaceous papules in this distribution among HED patients has rarely been reported. An association with the blockage of the Wnt/ß-catenin pathway due to EDA malfunction has been speculated.

Quantifying variant contributions in cystic kidney disease using national-scale whole-genome sequencing.

BACKGROUNDCystic kidney disease (CyKD) is a predominantly familial disease in which gene discovery has been led by family-based and candidate gene studies, an approach that is susceptible to ascertainment and other biases.METHODSUsing whole-genome sequencing data from 1,209 cases and 26,096 ancestry-matched controls participating in the 100,000 Genomes Project, we adopted hypothesis-free approaches to generate quantitative estimates of disease risk for each genetic contributor to CyKD, across genes, variant types and allelic frequencies.RESULTSIn 82.3% of cases, a qualifying potentially disease-causing rare variant in an established gene was found. There was an enrichment of rare coding, splicing, and structural variants in known CyKD genes, with statistically significant gene-based signals in COL4A3 and (monoallelic) PKHD1. Quantification of disease risk for each gene (with replication in the separate UK Biobank study) revealed substantially lower risk associated with genes more recently associated with autosomal dominant polycystic kidney disease, with odds ratios for some below what might usually be regarded as necessary for classical Mendelian inheritance. Meta-analysis of common variants did not reveal significant associations, but suggested this category of variation contributes 3%-9% to the heritability of CyKD across European ancestries.CONCLUSIONBy providing unbiased quantification of risk effects per gene, this research suggests that not all rare variant genetic contributors to CyKD are equally likely to manifest as a Mendelian trait in families. This information may inform genetic testing and counseling in the clinic.

Evaluating precision medicine approaches for gene therapy in patient-specific cellular models of Bietti crystalline dystrophy.

Patient-specific induced pluripotent stem cell-derived (iPSC-derived) cell lines allow for therapies to be tailored to individual patients, increasing therapeutic precision and efficiency. Bietti crystalline dystrophy (BCD) is a rare blinding disease estimated to affect about 67,000 individuals worldwide. Here, we used iPSC-derived retinal pigment epithelium (iRPE) cells from patients with BCD to evaluate adeno-associated virus-mediated (AAV-mediated) gene augmentation therapy strategies. We found that BCD iRPE cells were vulnerable to blue light-induced oxidative stress and that cellular phenotype can be quantified using 3 robust biomarkers: reactive oxygen species (ROS), 4-hydroxy 2-nonenal (4-HNE) levels, and cell death rate. Additionally, we demonstrated that AAV-mediated gene therapy can significantly reduce light-induced cell death in BCD iRPE cells. This is the first proof-of-concept study to our knowledge to show that AAV-CYP4V2 gene therapy can be used to treat light-induced RPE damage in BCD. Furthermore, we observed significant variability in cellular phenotypes among iRPE from patients with BCD of divergent mutations, which outlined genotype-phenotype correlations in BCD patient-specific cell disease models. Our results reveal that patient-specific iRPE cells retained personalized responses to AAV-mediated gene therapy. Therefore, this approach can advance BCD therapy and set a precedent for precision medicine in other diseases, emphasizing the necessity for personalization in healthcare to accommodate individual diversity.

Segmental congenital vascular anomaly with atrophy, ulceration, and scarring (SeCVAUS): Case series and review of literature.

BACKGROUND: Next-generation sequencing has greatly increased our understanding of vascular birthmarks. Many port-wine birthmarks are due to somatic mutations in GNAQ/GNA11 exon 183, but other genomic causes have been identified. Most congenital hemangiomas are due to somatic mutations in GNAQ/GNA11 at exon 209. Although genomically distinct, clinical overlap of congenital hemangiomas and port-wine birthmarks has occasionally been described. OBJECTIVE: We report a case series of a unique segmentally distributed vascular anomaly with overlapping characteristics of port-wine birthmarks and congenital hemangiomas with other distinctive features including ulceration, atrophy, and scarring. METHODS: This was a multicenter study with retrospective identification of patients via a detailed review of medical records. We also reviewed previously published cases. RESULTS: The clinical, histological, radiological, and genomic characteristics of 19 new and 13 previously reported cases characterized by segmental distribution, sharply demarcated borders, with variable thickening are presented. All cases had central atrophy with or without episodic ulceration. Those with genomic studies (13 out of 32) had somatic activating missense mutations in GNA11 or GNAQ codon 209. CONCLUSIONS: We describe the features and propose a descriptive name segmental congenital vascular anomaly with atrophy, ulceration, and scarring (SeCVAUS) for this condition.

Awareness of consanguineous marriage burden and willingness towards premarital genetic testing in Sudan: a national cross-sectional study.

Background: Despite the widespread practice of consanguinity in Sudan, there is a lack of exploration into the community's awareness of its health implications on offspring and their overall attitude towards consanguineous unions. Aim: This study aimed to evaluate the community's awareness of the possible health adversities of consanguinity on children and assess the effect of knowledge level on the prevailing attitude towards this practice in Sudan. Methods: From August to December 2018, data were collected from adults aged 18 years and above in five provinces of Sudan regardless of their marital status. The analysis involved both descriptive and multivariate statistical techniques. Results: This study revealed a consanguinity rate of 30.2%. Despite a high awareness level (73.7%) regarding the effects of consanguineous marriage on the health of the offspring, a moderately negative attitude towards this practice (63.9%) was observed. Conclusion: The discordance between the high consanguinity rate in the Sudanese population and the moderately negative attitude suggests a potential persistence of this practice in the future. Without the implementation of educational programs and the provision of genetic counselling services to consanguineous couples, the prevalence of consanguinity is likely to endure.

Global seroprevalence of neutralizing antibodies against adeno-associated virus serotypes used for human gene therapies.

Adeno-associated virus (AAV) vectors are promising gene therapy candidates, but pre-existing anti-AAV neutralizing antibodies (NAbs) pose a significant challenge to successful gene delivery. Knowledge of NAb seroprevalence remains limited and inconsistent. We measured activity of NAbs against six clinically relevant AAV serotypes across 10 countries in adults (n = 502) and children (n = 50) using a highly sensitive transduction inhibition assay. NAb prevalence was generally highest for AAV1 and lowest for AAV5. There was considerable variability across countries and geographical regions. NAb prevalence increased with age and was higher in females, participants of Asian ethnicity, and participants in cancer trials. Co-prevalence was most frequently observed between AAV1 and AAV6 and less frequently between AAV5 and other AAVs. Machine learning analyses revealed a unique clustering of AAVs that differed from previous phylogenetic classifications. These results offer insights into the biological relationships between the immunogenicity of AAVs in humans beyond that observed previously using standard clades, which are based on linear capsid sequences. Our findings may inform improved vector design and facilitate the development of AAV vector-mediated clinical gene therapies.

Simultaneous Pancreatic and Kidney Transplant in Adult with Autosomal Dominant Polycystic Kidney Disease and Type I Diabetes Mellitus: Post Surgical Events and Genetic Review.

Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited condition characterized by the growth of multiple bilateral cysts in the kidneys. We describe the case of a 35-year-old male with combined ADPKD and type 1 diabetes mellitus with a strong family history of both. At the age of 32, he developed end-stage kidney disease for which he underwent preemptive simultaneous pancreatic and kidney transplant, which in turn led to multiple perioperative complications. Evaluation of familial clustering of genetic disease is critical in genetic epidemiology and precision medicine as it enables estimation of lifetime disease risk and early assessment as well as detection of the disease among one's siblings.

Noonan syndrome-like disorder: Case report and review of the literature.

Of patients with a Noonan syndrome phenotype, only about 1% are found to be related to pathological variants in CBL, also known as Noonan syndrome-like disorder (NSLD). We present a case of a 4-year-old boy diagnosed with NSLD, presenting with multiple melanocytic nevi and superficial neurofibromas. A literature review identified common cutaneous findings of NSLD, for example, café-au-lait macules (22%), juvenile xanthogranuloma (16%), and thin hair (10%). As there are no documented cases of neurofibromas associated with NSLD, and only a single report of multiple melanocytic nevi, inclusion of these features in the phenotype may be warranted and mitigate the necessity for future biopsies in other children.

Preexisting maternal immunity to AAV but not Cas9 impairs in utero gene editing in mice.

In utero gene editing (IUGE) is a potential treatment for inherited diseases that cause pathology before or soon after birth. Preexisting immunity to adeno-associated virus (AAV) vectors and Cas9 endonuclease may limit postnatal gene editing. The tolerogenic fetal immune system minimizes a fetal immune barrier to IUGE. However, the ability of maternal immunity to limit fetal gene editing remains a question. We investigated whether preexisting maternal immunity to AAV or Cas9 impairs IUGE. Using a combination of fluorescent reporter mice and a murine model of a metabolic liver disease, we demonstrated that maternal anti-AAV IgG antibodies were efficiently transferred from dam to fetus and impaired IUGE in a maternal titer-dependent fashion. By contrast, maternal cellular immunity was inefficiently transferred to the fetus, and neither maternal cellular nor humoral immunity to Cas9 impaired IUGE. Using human umbilical cord and maternal blood samples collected from mid- to late-gestation pregnancies, we demonstrated that maternal-fetal transmission of anti-AAV IgG was inefficient in midgestation compared with term, suggesting that the maternal immune barrier to clinical IUGE would be less relevant at midgestation. These findings support immunologic advantages for IUGE and inform maternal preprocedural testing protocols and exclusion criteria for future clinical trials.

Transcriptional analysis of primary ciliary dyskinesia airway cells reveals a dedicated cilia glutathione pathway.

Primary ciliary dyskinesia (PCD) is a genetic condition that results in dysmotile cilia. The repercussions of cilia dysmotility and gene variants on the multiciliated cell remain poorly understood. We used single-cell RNA-Seq, proteomics, and advanced microscopy to compare primary culture epithelial cells from patients with PCD, their heterozygous mothers, and healthy individuals, and we induced pluripotent stem cells (iPScs) generated from a patient with PCD. Transcriptomic analysis revealed unique signatures in PCD airway cells compared with their mothers' cells and the cells of healthy individuals. Gene expression in heterozygous mothers' cells diverged from both control and PCD cells, marked by increased inflammatory and cellular stress signatures. Primary and iPS-derived PCD multiciliated cells had increased expression of glutathione-S-transferases GSTA2 and GSTA1, as well as NRF2 target genes, accompanied by elevated levels of reactive oxygen species (ROS). Immunogold labeling in human cilia and proteomic analysis of the ciliated organism Chlamydomonas reinhardtii demonstrated that GSTA2 localizes to motile cilia. Loss of human GSTA2 and C. reinhardtii GSTA resulted in slowed cilia motility, pointing to local cilia regulatory roles. Our findings identify cellular responses unique to PCD variants and independent of environmental stress and uncover a dedicated ciliary GSTA2 pathway essential for normal motility that may be a therapeutic target.