This piece narrates the journey of Maria (name of the mother has been altered to protect the family\'s privacy), a new mother confronting her newborn\'s unexpected diagnosis of very long chain acyl-CoA dehydrogenase (VLCAD) deficiency, despite undergoing proactive genetic carrier screening within a consanguineous marriage. It highlights the emotional and systemic challenges arising from the lack of diversity in genetic databases, which, in this case, failed to detect pathogenic variants in Maria and her husband. Maria\'s story sheds light on situations where a masked variant of uncertain significance (VUS) necessitates consultation with a trained genetics specialist and underscores the urgent need for a more equitable healthcare system.

BACKGROUND: There are no established guidelines for the follow up of infants born after a prenatal diagnosis of a genomic copy number variant (CNV), despite their increased risk of developmental issues. The aims of this study were (i) to determine the perinatal outcomes of fetuses diagnosed with and without a CNV, and (ii) to establish a population-based paediatric cohort for long term developmental follow up.
METHODS: An Australian state-wide research database was screened for pregnant individuals who had a prenatal chromosomal microarray (CMA) between 2013-2019 inclusive. Following linkage to laboratory records and clinical referrer details, hospital records were manually reviewed for study eligibility. Eligible participants were mother-child pairs where the pregnancy resulted in a livebirth, the mother was able to provide informed consent in English (did not require a translator) and the mother was the primary caregiver for the child at hospital discharge after birth. Research invitations were sent by registered post at an average of six years after the prenatal diagnostic test. Statistical analysis was performed in Stata17.
RESULTS: Of 1832 prenatal records examined, 1364 (74.5%) mother-child pairs were eligible for recruitment into the follow up cohort. Of the 468 ineligible, 282 (60.3%) had \'no live pregnancy outcome\' (209 terminations of pregnancy (TOP) and 73 miscarriages, stillbirths, and infant deaths), 157 (33.5%) required a translator, and 29 (6.2%) were excluded for other reasons. TOP rates varied by the type of fetal CNV detected: 49.3% (109/221) for pathogenic CNVs, 18.2% (58/319) for variants of uncertain significance and 3.3% (42/1292) where no clinically significant CNV was reported on CMA. Almost 77% of invitation letters were successfully delivered (1047/1364), and the subsequent participation rate in the follow up cohort was 19.2% (201/1047).
CONCLUSIONS: This study provides Australia\'s first population-based data on perinatal outcomes following prenatal diagnostic testing with CMA. The relatively high rates of pregnancy loss for those with a prenatal diagnosis of a CNV presented a challenge for establishing a paediatric cohort to examine long term outcomes. Recruiting a mother-child cohort via prenatal ascertainment is a complex and resource-intensive process, but an important step in understanding the impact of a CNV diagnosis in pregnancy and beyond.
BACKGROUND: ACTRN12620000446965p; Registered on April 6, 2020.

Functional enhancer annotation is critical for understanding tissue-specific transcriptional regulation and prioritizing disease-associated non-coding variants. However, unbiased enhancer discovery in disease-relevant contexts remains challenging. To identify enhancers pertinent to diabetes, we conducted a CRISPR interference (CRISPRi) screen in the human pluripotent stem cell (hPSC) pancreatic differentiation system. Among the enhancers identified, we focused on an enhancer we named ONECUT1e-664kb, ∼664 kb from the ONECUT1 promoter. Previous studies have linked ONECUT1 coding mutations to pancreatic hypoplasia and neonatal diabetes. We found that homozygous deletion of ONECUT1e-664kb in hPSCs leads to a near-complete loss of ONECUT1 expression and impaired pancreatic differentiation. ONECUT1e-664kb contains a type 2 diabetes-associated variant (rs528350911) disrupting a GATA motif. Introducing the risk variant into hPSCs reduced binding of key pancreatic transcription factors (GATA4, GATA6, and FOXA2), supporting its causal role in diabetes. This work highlights the utility of unbiased enhancer discovery in disease-relevant settings for understanding monogenic and complex disease.

Juvenile polyposis syndrome (JPS) is an inherited autosomal dominant condition that predisposes to the development of juvenile polyps throughout the gastrointestinal (GI) tract, and it poses an increased risk of GI malignancy. Germline causative variants were identified in the SMAD4 gene in a subset (20%) of JPS cases. Most SMAD4 germline genetic variants published to date are missense, nonsense, and frameshift mutations. SMAD4 germline alterations predicted to result in aberrant splicing have rarely been reported. Here, we report two unrelated Italian families harboring two different SMAD4 intronic variants, c.424+5G>A and c.425-9A>G, which are clinically associated with colorectal cancer and/or juvenile GI polyps. In silico prediction analysis, in vitro minigene assays, and RT-PCR showed that the identified variants lead to aberrant SMAD4 splicing via the exonization of intronic nucleotides, resulting in a premature stop codon. This is expected to cause the production of a truncated protein. This study expands the landscape of SMAD4 germline genetic variants associated with GI polyposis and/or cancer. Moreover, it emphasizes the importance of the functional characterization of SMAD4 splicing variants through RNA analysis, which can provide new insights into genetic disease variant interpretation, enabling tailored genetic counseling, management, and surveillance of patients with GI polyposis and/or cancer.

Pathogenic variants in the JAG1 gene are a primary cause of the multi-system disorder Alagille syndrome. Although variant detection rates are high for this disease, there is uncertainty associated with the classification of missense variants that leads to reduced diagnostic yield. Consequently, up to 85% of reported JAG1 missense variants have uncertain or conflicting classifications. We generated a library of 2,832 JAG1 nucleotide variants within exons 1-7, a region with a high number of reported missense variants, and designed a high-throughput assay to measure JAG1 membrane expression, a requirement for normal function. After calibration using a set of 175 known or predicted pathogenic and benign variants included within the variant library, 486 variants were characterized as functionally abnormal (n = 277 abnormal and n = 209 likely abnormal), of which 439 (90.3%) were missense. We identified divergent membrane expression occurring at specific residues, indicating that loss of the wild-type residue itself does not drive pathogenicity, a finding supported by structural modeling data and with broad implications for clinical variant classification both for Alagille syndrome and globally across other disease genes. Of 144 uncertain variants reported in patients undergoing clinical or research testing, 27 had functionally abnormal membrane expression, and inclusion of our data resulted in the reclassification of 26 to likely pathogenic. Functional evidence augments the classification of genomic variants, reducing uncertainty and improving diagnostics. Inclusion of this repository of functional evidence during JAG1 variant reclassification will significantly affect resolution of variant pathogenicity, making a critical impact on the molecular diagnosis of Alagille syndrome.

Variants of uncertain significance (VUS) surged with affordable genetic testing, posing challenges for determining pathogenicity. We examine the pathogenicity of a novel VUS P93S in Annexin A11 (ANXA11) - an amyotrophic lateral sclerosis/frontotemporal dementia-associated gene - in a corticobasal syndrome kindred. Established ANXA11 mutations cause ANXA11 aggregation, altered lysosomal-RNA granule co-trafficking, and transactive response DNA binding protein of 43 kDa (TDP-43) mis-localization.
We described the clinical presentation and explored the phenotypic diversity of ANXA11 variants. P93S\'s effect on ANXA11 function and TDP-43 biology was characterized in induced pluripotent stem cell-derived neurons alongside multiomic neuronal and microglial profiling.
ANXA11 mutations were linked to corticobasal syndrome cases. P93S led to decreased lysosome colocalization, neuritic RNA, and nuclear TDP-43 with cryptic exon expression. Multiomic microglial signatures implicated immune dysregulation and interferon signaling pathways.
This study establishes ANXA11 P93S pathogenicity, broadens the phenotypic spectrum of ANXA11 mutations, underscores neuronal and microglial dysfunction in ANXA11 pathophysiology, and demonstrates the potential of cellular models to determine variant pathogenicity.
ANXA11 P93S is a pathogenic variant. Corticobasal syndrome is part of the ANXA11 phenotypic spectrum. Hybridization chain reaction fluorescence in situ hybridization (HCR FISH) is a new tool for the detection of cryptic exons due to TDP-43-related loss of splicing regulation. Microglial ANXA11 and related immune pathways are important drivers of disease. Cellular models are powerful tools for adjudicating variants of uncertain significance.

A Variant of Uncertain Significance (VUS) is a difference in the DNA sequence with uncertain consequences for gene function. A VUS in a hereditary cancer gene should not change medical care, yet some patients undergo medical procedures based on their VUS result, highlighting the unmet educational needs among patients and healthcare providers. To address this need, we developed, evaluated, and refined novel educational materials to explain that while VUS results do not change medical care, it remains important to share any personal or family history of cancer with family members given that their personal and family medical history can guide their cancer risk management. We began by reviewing the prior literature and transcripts from interviews with six individuals with a VUS result to identify content and design considerations to incorporate into educational materials. We then gathered feedback to improve materials via a focus group of multidisciplinary experts and multiple rounds of semi-structured interviews with individuals with a VUS result. Themes for how to improve content, visuals, and usefulness were used to refine the materials. In the final round of interviews with an additional 10 individuals with a VUS result, materials were described as relatable, useful, factual, and easy to navigate, and also increased their understanding of cancer gene VUS results.

Hypophosphatasia (HPP) is a rare, inherited metabolic disease characterized by low tissue-nonspecific alkaline phosphatase activity due to ALPL gene variants. We describe ALPL variants from the observational, prospective, multinational Global HPP Registry. Inclusion in the analysis required a diagnosis of HPP, low serum ALP activity, and ≥1 ALPL variant. Of 1176 patients enrolled as of September 2022, 814 met inclusion criteria in Europe (48.9%), North America (36.7%), Japan (10.2%), Australia (2.6%), and elsewhere (1.6%). Most patients (74.7%) had 1 ALPL variant; 25.3% had ≥2 variants. Nearly all patients (95.6%) had known disease-causing variants; 4.4% had variants of uncertain significance. Disease-causing variants were predominantly missense (770/1556 alleles). The most common variants were c.571G>A (102/1628 alleles), c.1250A>G (66/1628 alleles), and c.1559del (61/1628 alleles). Variant profiles were generally consistent, except in Japan, where a higher proportion of patients (68.7%) had ≥2 ALPL variants, likely because more had disease onset before age 6 months (53.0% vs. 10.1%-23.1% elsewhere). Frameshift mutations (61/164 alleles) and inframe deletions (7/164 alleles) were more common in Japan. Twenty-three novel variants were discovered, each in a single geographic region, predominantly Europe. Analyses confirmed previously known ALPL variants, identified novel variants, and characterized geographic variation in frequency and type of ALPL variants in a large population.

UNASSIGNED: Modeling disease variants in animals is useful for drug discovery, understanding disease pathology, and classifying variants of uncertain significance (VUS) as pathogenic or benign.
UNASSIGNED: Using Clustered Regularly Interspaced Short Palindromic Repeats, we performed a Whole-gene Humanized Animal Model procedure to replace the coding sequence of the animal model\'s unc-18 ortholog with the coding sequence for the human STXBP1 gene. Next, we used Clustered Regularly Interspaced Short Palindromic Repeats to introduce precise point variants in the Whole-gene Humanized Animal Model-humanized STXBP1 locus from 3 clinical categories (benign, pathogenic, and VUS). Twenty-six phenotypic features extracted from video recordings were used to train machine learning classifiers on 25 pathogenic and 32 benign variants.
UNASSIGNED: Using multiple models, we were able to obtain a diagnostic sensitivity near 0.9. Twenty-three VUS were also interrogated and 8 of 23 (34.8%) were observed to be functionally abnormal. Interestingly, unsupervised clustering identified 2 distinct subsets of known pathogenic variants with distinct phenotypic features; both p.Tyr75Cys and p.Arg406Cys cluster away from other variants and show an increase in swim speed compared with hSTXBP1 worms. This leads to the hypothesis that the mechanism of disease for these 2 variants may differ from most STXBP1-mutated patients and may account for some of the clinical heterogeneity observed in the patient population.
UNASSIGNED: We have demonstrated that automated analysis of a small animal system is an effective, scalable, and fast way to understand functional consequences of variants in STXBP1 and identify variant-specific intensities of aberrant activity suggesting a genotype-to-phenotype correlation is likely to occur in human clinical variations of STXBP1.

UNASSIGNED: Genetic testing is increasingly utilized in nephrology practice, but limited real-world data exist on variant reclassification following renal genetics testing.
UNASSIGNED: A cohort of patients at the Cleveland Clinic Renal Genetics Clinic who underwent genetic testing through clinical laboratories was assessed with their clinical and laboratory data analyzed.
UNASSIGNED: Between January 2019 and June 2023, 425 new patients with variable kidney disorders from 413 pedigrees completed genetic testing through 10 clinical laboratories, including 255 (60%) females with median (25th, 75th percentiles) age of 36 (22-54) years. Multigene panel was the most frequently used modality followed by single-gene testing, exome sequencing (ES), chromosomal microarray (CMA), and genome sequencing (GS). At initial report, 52% of patients had ≥1 variants of uncertain significance (VUS) with or without concurrent pathogenic variant(s). Twenty amendments were issued across 19 pedigrees involving 19 variants in 17 genes. The overall variant reclassification rate was 5%, with 63% being upgrades and 32% downgrades. Of the reclassified variants, 79% were initially reported as VUS. The median time-to-amendments from initial reports was 8.4 (4-27) months. Following the variant reclassifications, 60% of the patients received a new diagnosis or a change in diagnosis. Among these, 67% of patients received significant changes in clinical management.
UNASSIGNED: Variant reclassification following genetic testing is infrequent but important for diagnosis and management of patients with suspected genetic kidney disease. The majority of variant reclassifications involve VUS and are upgrades in clinically issued amended reports. Further studies are needed to investigate the predictors of such events.