Ther Adv Rare Dis. 2024 Jul 31;5:26330040241263972. doi: 10.1177/26330040241263972. eCollection 2024 Jan-Dec. ABSTRACT TESS Research Foundation (TESS) is a patient-led nonprofit organization seeking to understand the basic biology and clinical impact of pathogenic variants in the SLC13A5 gene. TESS aims to improve the fundamental understanding of citrate’s role in the brain, and ultimately identify treatments and cures for the associated disease. TESS identifies, organizes, and develops collaboration between researchers, patients, clinicians, and the pharmaceutical industry to improve the lives of those suffering from SLC13A5 citrate transport disorder. TESS and its partners have developed multiple molecular tools, cellular and animal models, and taken the first steps toward drug discovery and development for this disease. However, much remains to be done to improve our understanding of the disorder associated with SLC13A5 variants and identify effective treatments for this devastating disease. Here, we describe the available SLC13A5 resources from the community of experts, to foundational tools, to in vivo and in vitro tools, and discuss unanswered research questions needed to move closer to a cure. PMID:39091896 | PMC:PMC11292725 | DOI:10.1177/26330040241263972

J Pediatr. 2024 Jul 4:114180. doi: 10.1016/j.jpeds.2024.114180. Online ahead of print. ABSTRACT To evaluate a novel candidate disease gene, we engaged international collaborators and identified rare, biallelic, specifically homozygous, loss of function variants in SENP7 in four children from three unrelated families presenting with neurodevelopmental abnormalities, dysmorphism, and immunodeficiency. Their clinical presentations were characterized by hypogammaglobulinemia, intermittent neutropenia, and ultimately death in infancy for all four patients. SENP7 is a sentrin-specific protease involved in posttranslational modification of proteins essential for cell regulation, via a process referred to as deSUMOylation. We propose that deficiency of deSUMOylation may represent a novel mechanism of primary immunodeficiency. PMID:38972567 | DOI:10.1016/j.jpeds.2024.114180

N Engl J Med. 2024 Jun 6;390(21):1985-1997. doi: 10.1056/NEJMoa2314761. ABSTRACT BACKGROUND: Genetic variants that cause rare disorders may remain elusive even after expansive testing, such as exome sequencing. The diagnostic yield of genome sequencing, particularly after a negative evaluation, remains poorly defined. METHODS: We sequenced and analyzed the genomes of families with diverse phenotypes who were suspected to have a rare monogenic disease and for whom genetic testing had not revealed a diagnosis, as well as the genomes of a replication cohort at an independent clinical center. RESULTS: We sequenced the genomes of 822 families (744 in the initial cohort and 78 in the replication cohort) and made a molecular diagnosis in 218 of 744 families (29.3%). Of the 218 families, 61 (28.0%) – 8.2% of families in the initial cohort – had variants that required genome sequencing for identification, including coding variants, intronic variants, small structural variants, copy-neutral inversions, complex rearrangements, and tandem repeat expansions. Most families in which a molecular diagnosis was made after previous nondiagnostic exome sequencing (63.5%) had variants that could be detected by reanalysis of the exome-sequence data (53.4%) or by additional analytic methods, such as copy-number variant calling, to exome-sequence data (10.8%). We obtained similar results in the replication cohort: in 33% of the families in which a molecular diagnosis was made, or 8% of the cohort, genome sequencing was required, which showed the applicability of these findings to both research and clinical environments. CONCLUSIONS: The diagnostic yield of genome sequencing in a large, diverse research cohort and in a small clinical cohort of persons who had previously undergone genetic testing was approximately 8% and included several types of pathogenic variation that had not previously been detected by means of exome sequencing or other techniques. (Funded by the National Human Genome Research Institute and others.). PMID:38838312 | DOI:10.1056/NEJMoa2314761

NPJ Genom Med. 2024 Mar 27;9(1):23. doi: 10.1038/s41525-024-00410-2. NO ABSTRACT PMID:38538605 | DOI:10.1038/s41525-024-00410-2

NPJ Genom Med. 2024 Feb 26;9(1):15. doi: 10.1038/s41525-024-00396-x. ABSTRACT Early use of genome sequencing (GS) in the diagnostic odyssey can reduce suffering and improve care, but questions remain about which patient populations are most amenable to GS as a first-line diagnostic test. To address this, the Medical Genome Initiative conducted a literature review to identify appropriate clinical indications for GS. Studies published from January 2011 to August 2022 that reported on the diagnostic yield (DY) or clinical utility of GS were included. An exploratory meta-analysis using a random effects model evaluated DY based on cohort size and diagnosed cases per cohort. Seventy-one studies met inclusion criteria, comprising over 13,000 patients who received GS in one of the following settings: hospitalized pediatric patients, pediatric outpatients, adult outpatients, or mixed. GS was the first-line test in 38% (27/71). The unweighted mean DY of first-line GS was 45% (12-73%), 33% (6-86%) in cohorts with prior genetic testing, and 33% (9-60%) in exome-negative cohorts. Clinical utility was reported in 81% of first-line GS studies in hospitalized pediatric patients. Changes in management varied by cohort and underlying molecular diagnosis (24-100%). To develop evidence-informed points to consider, the quality of all 71 studies was assessed using modified American College of Radiology (ACR) criteria, with five core points to consider developed, including recommendations for use of GS in the N/PICU, in lieu of sequential testing and when disorders with substantial allelic heterogeneity are suspected. Future large and controlled studies in the pediatric and adult populations may support further refinement of these recommendations. PMID:38409289 | DOI:10.1038/s41525-024-00396-x

bioRxiv [Preprint]. 2024 Feb 16:2024.02.13.580158. doi: 10.1101/2024.02.13.580158. ABSTRACT Genomics for rare disease diagnosis has advanced at a rapid pace due to our ability to perform “N-of-1” analyses on individual patients. The increasing sizes of ultra-rare, “N-of-1” disease cohorts internationally newly enables cohort-wide analyses for new discoveries, but well-calibrated statistical genetics approaches for jointly analyzing these patients are still under development. The Undiagnosed Diseases Network (UDN) brings multiple clinical, research and experimental centers under the same umbrella across the United States to facilitate and scale N-of-1 analyses. Here, we present the first joint analysis of whole genome sequencing data of UDN patients across the network. We apply existing and introduce new, well-calibrated statistical methods for prioritizing disease genes with de novo recurrence and compound heterozygosity. We also detect pathways enriched with candidate and known diagnostic genes. Our computational analysis, coupled with a systematic clinical review, recapitulated known diagnoses and revealed new disease associations. We make our gene-level findings and variant-level information across the cohort available in a public-facing browser (https://dbmi-bgm.github.io/udn-browser/). These results show that N-of-1 efforts should be supplemented by a joint genomic analysis across cohorts. PMID:38405764 | PMC:PMC10888768 | DOI:10.1101/2024.02.13.580158

Nat Commun. 2023 Nov 1;14(1):6770. doi: 10.1038/s41467-023-42150-4. ABSTRACT Type I interferon (IFN) signalling is tightly controlled. Upon recognition of DNA by cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING) translocates along the endoplasmic reticulum (ER)-Golgi axis to induce IFN signalling. Termination is achieved through autophagic degradation or recycling of STING by retrograde Golgi-to-ER transport. Here, we identify the GTPase ADP-ribosylation factor 1 (ARF1) as a crucial negative regulator of cGAS-STING signalling. Heterozygous ARF1 missense mutations cause a previously unrecognized type I interferonopathy associated with enhanced IFN-stimulated gene expression. Disease-associated, GTPase-defective ARF1 increases cGAS-STING dependent type I IFN signalling in cell lines and primary patient cells. Mechanistically, mutated ARF1 perturbs mitochondrial morphology, causing cGAS activation by aberrant mitochondrial DNA release, and leads to accumulation of active STING at the Golgi/ERGIC due to defective retrograde transport. Our data show an unexpected dual role of ARF1 in maintaining cGAS-STING homeostasis, through promotion of mitochondrial integrity and STING recycling. PMID:37914730 | DOI:10.1038/s41467-023-42150-4

medRxiv. 2023 Aug 13:2023.08.08.23293829. doi: 10.1101/2023.08.08.23293829. Preprint. ABSTRACT BACKGROUND: Causal variants underlying rare disorders may remain elusive even after expansive gene panels or exome sequencing (ES). Clinicians and researchers may then turn to genome sequencing (GS), though the added value of this technique and its optimal use remain poorly defined. We therefore investigated the advantages of GS within a phenotypically diverse cohort. METHODS: GS was performed for 744 individuals with rare disease who were genetically undiagnosed. Analysis included review of single nucleotide, indel, structural, and mitochondrial variants. RESULTS: We successfully solved 218/744 (29.3%) cases using GS, with most solves involving established disease genes (157/218, 72.0%). Of all solved cases, 148 (67.9%) had previously had non-diagnostic ES. We systematically evaluated the 218 causal variants for features requiring GS to identify and 61/218 (28.0%) met these criteria, representing 8.2% of the entire cohort. These included small structural variants (13), copy neutral inversions and complex rearrangements (8), tandem repeat expansions (6), deep intronic variants (15), and coding variants that may be more easily found using GS related to uniformity of coverage (19). CONCLUSION: We describe the diagnostic yield of GS in a large and diverse cohort, illustrating several types of pathogenic variation eluding ES or other techniques. Our results reveal a higher diagnostic yield of GS, supporting the utility of a genome-first approach, with consideration of GS as a secondary or tertiary test when higher-resolution structural variant analysis is needed or there is a strong clinical suspicion for a condition and prior targeted genetic testing has been negative. PMID:38328047 | PMC:PMC10849673 | DOI:10.1101/2023.08.08.23293829

JACC Case Rep. 2023 Feb 22;11:101790. doi: 10.1016/j.jaccas.2023.101790. eCollection 2023 Apr 5. ABSTRACT We present a 22-week fetus with isolated absent aortic valve and inverse circular shunt. The pregnancy was interrupted. Here, echocardiography and pathology images demonstrate this rare entity. Whole genome sequencing revealed a potentially disease-causing variant in the APC gene. Whole genome sequencing should be considered in severe and rare fetal diseases. (Level of Difficulty: Advanced.). PMID:37077433 DOI:10.1016/j.jaccas.2023.101790

PLoS One. 2023 Jan 26;18(1):e0279430. doi: 10.1371/journal.pone.0279430. eCollection 2023. ABSTRACT Short Tandem Repeats (STRs) have been found to play a role in a myriad of complex traits and genetic diseases. We examined the variability in the lengths of over 850,000 STR loci in 996 children with suspected genetic disorders and 1,178 parents across six separate ancestral groups: Africans, Europeans, East Asians, Admixed Americans, Non-admixed Americans, and Pacific Islanders. For each STR locus we compared allele length between and within each ancestry group. In relation to Europeans, admixed Americans had the most similar STR lengths with only 623 positions either significantly expanded or contracted, while the divergence was highest in Africans, with 4,933 chromosomal positions contracted or expanded. We also examined probands to identify STR expansions at known pathogenic loci. The genes TCF4, AR, and DMPK showed significant expansions with lengths 250% greater than their various average allele lengths in 49, 162, and 11 individuals respectively. All 49 individuals containing an expansion in TCF4 and six individuals containing an expansion in DMPK presented with allele lengths longer than the known pathogenic length for these genes. Next, we identified individuals with significant expansions in highly conserved loci across all ancestries. Eighty loci in conserved regions met criteria for divergence. Two of these individuals were found to have exonic STR expansions: one in ZBTB4 and the other in SLC9A7, which is associated with X-linked mental retardation. Finally, we used parent-child trios to detect and analyze de novo mutations. In total, we observed 3,219 de novo expansions, where proband allele lengths are greater than twice the longest parental allele length. This work helps lay the foundation for understanding STR lengths genome-wide across ancestries and may help identify new disease genes and novel mechanisms of pathogenicity in known disease genes. PMID:36701310 DOI:10.1371/journal.pone.0279430