Genet Med. 2023 Jul 30:100947. doi: 10.1016/j.gim.2023.100947. Online ahead of print. ABSTRACT PURPOSE: Variants of uncertain significance (VUS) are a common result of diagnostic genetic testing and can be difficult to manage with potential misinterpretation and downstream costs, including time investment by clinicians. We investigated the rate of VUS reported on diagnostic testing via multi-gene panels (MGPs) and exome and genome sequencing (ES/GS) to measure the magnitude of uncertain results and explore ways to reduce their potentially detrimental impact. METHODS: Rates of inconclusive results due to VUS were collected from over 1.5 million sequencing test results from 19 clinical laboratories in North America from 2020 – 2021. RESULTS: We found a lower rate of inconclusive test results due to VUSs from ES/GS (22.5%) compared to MGPs (32.6%; p<0.0001). For MGPs, the rate of inconclusive results correlated with panel size. The use of trios reduced inconclusive rates (18.9% vs 27.6%; p<0.001) whereas the use of GS compared to ES had no impact (22.2% vs 22.6%; p=ns). CONCLUSION: The high rate of VUS observed in diagnostic MGP testing warrants examining current variant reporting practices. We propose several approaches to reduce reported VUS rates, while directing clinician resources towards important VUS follow-up. PMID:37534744 DOI:10.1016/j.gim.2023.100947

Clin Case Rep. 2023 Jul 30;11(8):e7753. doi: 10.1002/ccr3.7753. eCollection 2023 Aug. ABSTRACT We report two, genotypically identical but phenotypically distinct cases of Schaaf-Yang syndrome and propose the early use of Genome Sequencing in patients with nonspecific presentations to facilitate the early diagnosis of children with rare genetic diseases and improve overall health care outcomes. PMID:37529132 DOI:10.1002/ccr3.7753

Brain. 2023 Jul 17:awad235. doi: 10.1093/brain/awad235. Online ahead of print. ABSTRACT SLC4A10 is a plasma-membrane bound transporter which utilizes the Na+ gradient to drive cellular HCO3- uptake, thus mediating acid extrusion. In the mammalian brain, SLC4A10 is expressed in principal neurons and interneurons, as well as in epithelial cells of the choroid plexus, the organ regulating the production of cerebrospinal fluid. Using next generation sequencing on samples from five unrelated families encompassing ten affected individuals, we show that biallelic SLC4A10 loss-of-function variants cause a clinically recognizable neurodevelopmental disorder in humans. The cardinal clinical features of the condition include hypotonia in infancy, delayed psychomotor development across all domains and typically severe intellectual impairment. Affected individuals commonly display traits associated with autistic spectrum disorders including anxiety, hyperactivity and stereotyped movements. In two cases isolated episodes of seizures were reported in the first few years of life, and a further affected child displayed bitemporal epileptogenic discharges on EEG without overt clinical seizures. While occipitofrontal circumference was reported to be normal at birth, progressive postnatal microcephaly evolved in 7 out of 10 affected individuals. Neuroradiological features included a relative preservation of brain volume compared to occipitofrontal circumference, characteristic narrow sometimes ‘slit-like’ lateral ventricles and corpus callosum abnormalities. Slc4a10 -/- mice, deficient for SLC4A10, also display small lateral brain ventricles and mild behavioral abnormalities including delayed habituation and alterations in the 2-object novel object recognition task. Collapsed brain ventricles in both Slc4a10-/- mice and affected individuals suggests an important role of SLC4A10 in the production of the cerebrospinal fluid. However, it is notable that despite diverse roles of the cerebrospinal fluid in the developing and adult brain, the cortex of Slc4a10-/- mice appears grossly intact. Co-staining with synaptic markers revealed that in neurons, SLC4A10 localizes to inhibitory, but not excitatory, presynapses. These findings are supported by our functional studies which show the release of the inhibitory neurotransmitter GABA is compromised in Slc4a10-/- mice, while the release of the excitatory neurotransmitter glutamate is preserved. Manipulation of intracellular pH partially rescues GABA release. Together our studies define a novel characteristic neurodevelopmental disorder associated with biallelic pathogenic variants in SLC4A10 and highlight the importance of further analyses of the consequences of SLC4A10 loss-of-function for brain development, synaptic transmission and network properties. PMID:37459438 DOI:10.1093/brain/awad235

Clin Ther. 2023 Jul 8:S0149-2918(23)00220-5. doi: 10.1016/j.clinthera.2023.06.014. Online ahead of print. ABSTRACT PURPOSE: Diagnostic genomic research has the potential to directly benefit participants. This study sought to identify barriers to equitable enrollment of acutely ill newborns into a diagnostic genomic sequencing research study. METHODS: We reviewed the 16-month recruitment process of a diagnostic genomic research study enrolling newborns admitted to the neonatal intensive care unit at a regional pediatric hospital that primarily serves English- and Spanish-speaking families. Differences in eligibility, enrollment, and reasons for not enrolling were examined as functions of race/ethnicity and primary spoken language. FINDINGS: Of the 1248 newborns admitted to the neonatal intensive care unit, 46% (n = 580) were eligible, and 17% (n = 213) were enrolled. Of the 16 languages represented among the newborns’ families, 4 (25%) had translated consent documents. Speaking a language other than English or Spanish increased a newborn’s likelihood of being ineligible by 5.9 times (P < 0.001) after controlling for race/ethnicity. The main reason for ineligibility was documented as the clinical team declined having their patient recruited (41% [51 of 125]). This reason significantly affected families who spoke languages other than English or Spanish and was able to be remediated with training of the research staff. Stress (20% [18 of 90]) and the study intervention(s) (20% [18 of 90]) were the main reasons given for not enrolling. IMPLICATIONS: This analysis of eligibility, enrollment, and reasons for not enrolling in a diagnostic genomic research study found that recruitment generally did not differ as a function of a newborn’s race/ethnicity. However, differences were observed depending on the parent’s primary spoken language. Regular monitoring and training can improve equitable enrollment into diagnostic genomic research. There are also opportunities at the federal level to improve access to those with limited English proficiency and thus decrease disparities in representation in research participation. PMID:37429778 DOI:10.1016/j.clinthera.2023.06.014

Sci Adv. 2023 Jun 30;9(26):eadf2860. doi: 10.1126/sciadv.adf2860. Epub 2023 Jun 30. ABSTRACT Cell cycle dysregulation is prerequisite for cancer formation. However, it is unknown whether the mode of dysregulation affects disease characteristics. Here, we conduct comprehensive analyses of cell cycle checkpoint dysregulation using patient data and experimental investigations. We find that ATM mutation predisposes the diagnosis of primary estrogen receptor (ER)+/human epidermal growth factor (HER)2- cancer in older women. Conversely, CHK2 dysregulation induces formation of metastatic, premenopausal ER+/HER2- breast cancer (P = 0.001) that is treatment-resistant (HR = 6.15, P = 0.01). Lastly, while mutations in ATR alone are rare, ATR/TP53 co-mutation is 12-fold enriched over expected in ER+/HER2- disease (P = 0.002) and associates with metastatic progression (HR = 2.01, P = 0.006). Concordantly, ATR dysregulation induces metastatic phenotypes in TP53 mutant, not wild-type, cells. Overall, we identify mode of cell cycle dysregulation as a distinct event that determines subtype, metastatic potential, and treatment responsiveness, providing rationale for reconsidering diagnostic classification through the lens of the mode of cell cycle dysregulation.. PMID:37390209 DOI:10.1126/sciadv.adf2860

medRxiv. 2023 Jun 27:2023.06.19.23291425. doi: 10.1101/2023.06.19.23291425. Preprint. ABSTRACT Over two dozen spliceosome proteins are involved in human diseases, also referred to as spliceosomopathies. WBP4 (WW Domain Binding Protein 4) is part of the early spliceosomal complex, and was not described before in the context of human pathologies. Ascertained through GeneMatcher we identified eleven patients from eight families, with a severe neurodevelopmental syndrome with variable manifestations. Clinical manifestations included hypotonia, global developmental delay, severe intellectual disability, brain abnormalities, musculoskeletal and gastrointestinal abnormalities. Genetic analysis revealed overall five different homozygous loss-of-function variants in WBP4 . Immunoblotting on fibroblasts from two affected individuals with different genetic variants demonstrated complete loss of protein, and RNA sequencing analysis uncovered shared abnormal splicing patterns, including enrichment for abnormalities of the nervous system and musculoskeletal system genes, suggesting that the overlapping differentially spliced genes are related to the common phenotypes of the probands. We conclude that biallelic variants in WBP4 cause a spliceosomopathy. Further functional studies are called for better understanding of the mechanism of pathogenicity. PMID:37425688 DOI:10.1101/2023.06.19.23291425

Eur J Hum Genet. 2023 Jun 21. doi: 10.1038/s41431-023-01410-z. Online ahead of print. ABSTRACT BRAT1 biallelic variants are associated with rigidity and multifocal seizure syndrome, lethal neonatal (RMFSL), and neurodevelopmental disorder associating cerebellar atrophy with or without seizures syndrome (NEDCAS). To date, forty individuals have been reported in the literature. We collected clinical and molecular data from 57 additional cases allowing us to study a large cohort of 97 individuals and draw phenotype-genotype correlations. Fifty-nine individuals presented with BRAT1-related RMFSL phenotype. Most of them had no psychomotor acquisition (100%), epilepsy (100%), microcephaly (91%), limb rigidity (93%), and died prematurely (93%). Thirty-eight individuals presented a non-lethal phenotype of BRAT1-related NEDCAS phenotype. Seventy-six percent of the patients in this group were able to walk and 68% were able to say at least a few words. Most of them had cerebellar ataxia (82%), axial hypotonia (79%) and cerebellar atrophy (100%). Genotype-phenotype correlations in our cohort revealed that biallelic nonsense, frameshift or inframe deletion/insertion variants result in the severe BRAT1-related RMFSL phenotype (46/46; 100%). In contrast, genotypes with at least one missense were more likely associated with NEDCAS (28/34; 82%). The phenotype of patients carrying splice variants was variable: 41% presented with RMFSL (7/17) and 59% with NEDCAS (10/17). PMID:37344571 DOI:10.1038/s41431-023-01410-z

Genet Epidemiol. 2023 Jun 21. doi: 10.1002/gepi.22533. Online ahead of print. ABSTRACT The risk of congenital heart defects (CHDs) may be influenced by maternal genes, fetal genes, and their interactions. Existing methods commonly test the effects of maternal and fetal variants one-at-a-time and may have reduced statistical power to detect genetic variants with low minor allele frequencies. In this article, we propose a gene-based association test of interactions for maternal-fetal genotypes (GATI-MFG) using a case-mother and control-mother design. GATI-MFG can integrate the effects of multiple variants within a gene or genomic region and evaluate the joint effect of maternal and fetal genotypes while allowing for their interactions. In simulation studies, GATI-MFG had improved statistical power over alternative methods, such as the single-variant test and functional data analysis (FDA) under various disease scenarios. We further applied GATI-MFG to a two-phase genome-wide association study of CHDs for the testing of both common variants and rare variants using 947 CHD case mother-infant pairs and 1306 control mother-infant pairs from the National Birth Defects Prevention Study (NBDPS). After Bonferroni adjustment for 23,035 genes, two genes on chromosome 17, TMEM107 (p = 1.64e-06) and CTC1 (p = 2.0e-06), were identified for significant association with CHD in common variants analysis. Gene TMEM107 regulates ciliogenesis and ciliary protein composition and was found to be associated with heterotaxy. Gene CTC1 plays an essential role in protecting telomeres from degradation, which was suggested to be associated with cardiogenesis. Overall, GATI-MFG outperformed the single-variant test and FDA in the simulations, and the results of application to NBDPS samples are consistent with existing literature supporting the association of TMEM107 and CTC1 with CHDs. PMID:37341229 DOI:10.1002/gepi.22533

Am J Hum Genet. 2023 Jun 1;110(6):1017. doi: 10.1016/j.ajhg.2023.05.004. NO ABSTRACT PMID:37267897 DOI:10.1016/j.ajhg.2023.05.004

N Engl J Med. 2023 May 31. doi: 10.1056/NEJMoa2202318. Online ahead of print. ABSTRACT BACKGROUND: Disabling pansclerotic morphea (DPM) is a rare systemic inflammatory disorder, characterized by poor wound healing, fibrosis, cytopenias, hypogammaglobulinemia, and squamous-cell carcinoma. The cause is unknown, and mortality is high. METHODS: We evaluated four patients from three unrelated families with an autosomal dominant pattern of inheritance of DPM. Genomic sequencing independently identified three heterozygous variants in a specific region of the gene that encodes signal transducer and activator of transcription 4 (STAT4). Primary skin fibroblast and cell-line assays were used to define the functional nature of the genetic defect. We also assayed gene expression using single-cell RNA sequencing of peripheral-blood mononuclear cells to identify inflammatory pathways that may be affected in DPM and that may respond to therapy. RESULTS: Genome sequencing revealed three novel heterozygous missense gain-of-function variants in STAT4. In vitro, primary skin fibroblasts showed enhanced interleukin-6 secretion, with impaired wound healing, contraction of the collagen matrix, and matrix secretion. Inhibition of Janus kinase (JAK)-STAT signaling with ruxolitinib led to improvement in the hyperinflammatory fibroblast phenotype in vitro and resolution of inflammatory markers and clinical symptoms in treated patients, without adverse effects. Single-cell RNA sequencing revealed expression patterns consistent with an immunodysregulatory phenotype that were appropriately modified through JAK inhibition. CONCLUSIONS: Gain-of-function variants in STAT4 caused DPM in the families that we studied. The JAK inhibitor ruxolitinib attenuated the dermatologic and inflammatory phenotype in vitro and in the affected family members. (Funded by the American Academy of Allergy, Asthma, and Immunology Foundation and others.). PMID:37256972 DOI:10.1056/NEJMoa2202318