Quantitative analysis of the natural history of prolidase deficiency: description of 17 families and systematic review of published cases
Rossignol F, Duarte Moreno MS, Benoist JF, Boehm M, Bourrat E, Cano A, Chabrol B, Cosson C, Díaz JLD, D’Harlingue A, Dimmock D, Freeman AF, García MT, Garganta C, Goerge T, Halbach SS, de Laffolie J, Lam CT, Martin L, Martins E, Meinhardt A, Melki I, Ombrello AK, Pérez N, Quelhas D, Scott A, Slavotinek AM, Soares AR, Stein SL, Süßmuth K, Thies J, Ferreira CR, Schiff M.
Genet Med. 2021 May 26. doi: 10.1038/s41436-021-01200-2. Online ahead of print.
ABSTRACT
PURPOSE: Prolidase deficiency is a rare inborn error of metabolism causing ulcers and other skin disorders, splenomegaly, developmental delay, and recurrent infections. Most of the literature is constituted of isolated case reports. We aim to provide a quantitative description of the natural history of the condition by describing 19 affected individuals and reviewing the literature.
METHODS: Nineteen patients were phenotyped per local institutional procedures. A systematic review following PRISMA criteria identified 132 articles describing 161 patients. Main outcome analyses were performed for manifestation frequency, diagnostic delay, overall survival, symptom-free survival, and ulcer-free survival.
RESULTS: Our cohort presented a wide variability of severity. Autoimmune disorders were found in 6/19, including Crohn disease, systemic lupus erythematosus, and arthritis. Another immune finding was hemophagocytic lymphohistiocytosis (HLH). Half of published patients were symptomatic by age 4 and had a delayed diagnosis (mean delay 11.6 years). Ulcers were present initially in only 30% of cases, with a median age of onset at 12 years old.
CONCLUSION: Prolidase deficiency has a broad range of manifestations. Symptoms at onset may be nonspecific, likely contributing to the diagnostic delay. Testing for this disorder should be considered in any child with unexplained autoimmunity, lower extremity ulcers, splenomegaly, or HLH.
PMID:
34040193 | DOI:
10.1038/s41436-021-01200-2
June 2, 2021
Loss of C2orf69 defines a fatal autoinflammatory syndrome in humans and zebrafish that evokes a glycogen storage-associated mitochondriopathy
Am J Hum Genet. 2021 May 21:S0002-9297(21)00187-7. doi: 10.1016/j.ajhg.2021.05.003. Online ahead of print.
ABSTRACT
Human C2orf69 is an evolutionarily conserved gene whose function is unknown. Here, we report eight unrelated families from which 20 children presented with a fatal syndrome consisting of severe autoinflammation and progredient leukoencephalopathy with recurrent seizures; 12 of these subjects, whose DNA was available, segregated homozygous loss-of-function C2orf69 variants. C2ORF69 bears homology to esterase enzymes, and orthologs can be found in most eukaryotic genomes, including that of unicellular phytoplankton. We found that endogenous C2ORF69 (1) is loosely bound to mitochondria, (2) affects mitochondrial membrane potential and oxidative respiration in cultured neurons, and (3) controls the levels of the glycogen branching enzyme 1 (GBE1) consistent with a glycogen storage-associated mitochondriopathy. We show that CRISPR-Cas9-mediated inactivation of zebrafish C2orf69 results in lethality by 8 months of age due to spontaneous epileptic seizures, which is preceded by persistent brain inflammation. Collectively, our results delineate an autoinflammatory Mendelian disorder of C2orf69 deficiency that disrupts the development/homeostasis of the immune and central nervous systems.
PMID:
34038740 | DOI:
10.1016/j.ajhg.2021.05.003
May 27, 2021
Implementing Rapid Whole Genome Sequencing in Critical Care: A Qualitative Study of Facilitators and Barriers to New Technology Adoption
Franck LS, Kriz RM, Rego S, Garman K, Hobbs C, Dimmock D.
J Pediatr. 2021 May 20:S0022-3476(21)00496-0. doi: 10.1016/j.jpeds.2021.05.045. Online ahead of print.
ABSTRACT
OBJECTIVE: To characterize the views of members of the multi-disciplinary team regarding the implementation of Rapid Whole Genome Sequencing (rWGS) as a first-tier test for critically ill children in diverse children’s hospital settings.
STUDY DESIGN: Qualitative interviews informed by implementation science theory were conducted with the multi-disciplinary patient care teams and hospital leaders at each of the five tertiary care children’s hospitals involved in a statewide rWGS implementation project.
RESULTS: Our analysis revealed 5 key themes regarding the implementation process across the sites: the need for rWGS champions, educational needs and strategies, negotiating decision-making roles and processes, workflows and workarounds, and perceptions about rWGS. From the findings a composite clinical workflow diagram was developed to summarize all of the processes involved in the implementation of the test, and the key areas where implementation practices differed.
CONCLUSIONS: These findings provide insights for design of interventions to support adoption, scale-up and sustainability of rWGS and other novel technologies in neonatal and pediatric critical care settings.
PMID:
34023348 | DOI:
10.1016/j.jpeds.2021.05.045
May 24, 2021
rWGS
One in seven pathogenic variants can be challenging to detect by NGS: an analysis of 450,000 patients with implications for clinical sensitivity and genetic test implementation
Lincoln SE, Hambuch T, Zook JM, Bristow SL, Hatchell K, Truty R, Kennemer M, Shirts BH, Fellowes A, Chowdhury S, Klee EW, Mahamdallie S, Cleveland MH, Vallone PM, Ding Y, Seal S, DeSilva W, Tomson FL, Huang C, Garlick RK, Rahman N, Salit M, Kingsmore SF, Ferber MJ, Aradhya S, Nussbaum RL.
Genet Med. 2021 May 18. doi: 10.1038/s41436-021-01187-w. Online ahead of print.
ABSTRACT
PURPOSE: To evaluate the impact of technically challenging variants on the implementation, validation, and diagnostic yield of commonly used clinical genetic tests. Such variants include large indels, small copy-number variants (CNVs), complex alterations, and variants in low-complexity or segmentally duplicated regions.
METHODS: An interlaboratory pilot study used synthetic specimens to assess detection of challenging variant types by various next-generation sequencing (NGS)-based workflows. One well-performing workflow was further validated and used in clinician-ordered testing of more than 450,000 patients.
RESULTS: In the interlaboratory study, only 2 of 13 challenging variants were detected by all 10 workflows, and just 3 workflows detected all 13. Limitations were also observed among 11 less-challenging indels. In clinical testing, 21.6% of patients carried one or more pathogenic variants, of which 13.8% (17,561) were classified as technically challenging. These variants were of diverse types, affecting 556 of 1,217 genes across hereditary cancer, cardiovascular, neurological, pediatric, reproductive carrier screening, and other indicated tests.
CONCLUSION: The analytic and clinical sensitivity of NGS workflows can vary considerably, particularly for prevalent, technically challenging variants. This can have important implications for the design and validation of tests (by laboratories) and the selection of tests (by clinicians) for a wide range of clinical indications.
PMID:
3400 7000 | DOI:
10.1038/s41436-021-01187-w
May 19, 2021
Missense and truncating variants in CHD5 in a dominant neurodevelopmental disorder with intellectual disability, behavioral disturbances, and epilepsy
Parenti I, Lehalle D, Nava C, Torti E, Leitão E, Person R, Mizuguchi T, Matsumoto N, Kato M, Nakamura K, de Man SA, Cope H, Shashi V; Undiagnosed Diseases Network, Friedman J, Joset P, Steindl K, Rauch A, Muffels I, van Hasselt PM, Petit F, Smol T, Le Guyader G, Bilan F, Sorlin A, Vitobello A, Philippe C, van de Laar IMBH, van Slegtenhorst MA, Campeau PM, Au PYB, Nakashima M, Saitsu H, Yamamoto T, Nomura Y, Louie RJ, Lyons MJ, Dobson A, Plomp AS, Motazacker MM, Kaiser FJ, Timberlake AT, Fuchs SA, Depienne C, Mignot C.
Hum Genet. 2021 May 4. doi: 10.1007/s00439-021-02283-2. Online ahead of print.
ABSTRACT
Located in the critical 1p36 microdeletion region, the chromodomain helicase DNA-binding protein 5 (CHD5) gene encodes a subunit of the nucleosome remodeling and deacetylation (NuRD) complex required for neuronal development. Pathogenic variants in six of nine chromodomain (CHD) genes cause autosomal dominant neurodevelopmental disorders, while CHD5-related disorders are still unknown. Thanks to GeneMatcher and international collaborations, we assembled a cohort of 16 unrelated individuals harboring heterozygous CHD5 variants, all identified by exome sequencing. Twelve patients had de novo CHD5 variants, including ten missense and two splice site variants. Three familial cases had nonsense or missense variants segregating with speech delay, learning disabilities, and/or craniosynostosis. One patient carried a frameshift variant of unknown inheritance due to unavailability of the father. The most common clinical features included language deficits (81%), behavioral symptoms (69%), intellectual disability (64%), epilepsy (62%), and motor delay (56%). Epilepsy types were variable, with West syndrome observed in three patients, generalized tonic-clonic seizures in two, and other subtypes observed in one individual each. Our findings suggest that, in line with other CHD-related disorders, heterozygous CHD5 variants are associated with a variable neurodevelopmental syndrome that includes intellectual disability with speech delay, epilepsy, and behavioral problems as main features.
PMID:
33944996 | DOI:
10.1007/s00439-021-02283-2
May 11, 2021
Loss of function mutations in GEMIN5 cause a neurodevelopmental disorder
Kour S, Rajan DS, Fortuna TR, Anderson EN, Ward C, Lee Y, Lee S, Shin YB, Chae JH, Choi M, Siquier K, Cantagrel V, Amiel J, Stolerman ES, Barnett SS, Cousin MA, Castro D, McDonald K, Kirmse B, Nemeth AH, Rajasundaram D, Innes AM, Lynch D, Frosk P, Collins A, Gibbons M, Yang M, Desguerre I, Boddaert N, Gitiaux C, Rydning SL, Selmer KK, Urreizti R, Garcia-Oguiza A, Osorio AN, Verdura E, Pujol A, McCurry HR, Landers JE, Agnihotri S, Andriescu EC, Moody SB, Phornphutkul C, Sacoto MJG, Begtrup A, Houlden H, Kirschner J, Schorling D, Rudnik-Schöneborn S, Strom TM, Leiz S, Juliette K, Richardson R, Yang Y, Zhang Y, Wang M, Wang J, Wang X, Platzer K, Donkervoort S, Bönnemann CG, Wagner M, Issa MY, Elbendary HM, Stanley V, Maroofian R, Gleeson JG, Zaki MS, Senderek J, Pandey UB.
Nat Commun. 2021 May 7;12(1):2558. doi: 10.1038/s41467-021-22627-w.
ABSTRACT
GEMIN5, an RNA-binding protein is essential for assembly of the survival motor neuron (SMN) protein complex and facilitates the formation of small nuclear ribonucleoproteins (snRNPs), the building blocks of spliceosomes. Here, we have identified 30 affected individuals from 22 unrelated families presenting with developmental delay, hypotonia, and cerebellar ataxia harboring biallelic variants in the GEMIN5 gene. Mutations in GEMIN5 perturb the subcellular distribution, stability, and expression of GEMIN5 protein and its interacting partners in patient iPSC-derived neurons, suggesting a potential loss-of-function mechanism. GEMIN5 mutations result in disruption of snRNP complex assembly formation in patient iPSC neurons. Furthermore, knock down of rigor mortis, the fly homolog of human GEMIN5, leads to developmental defects, motor dysfunction, and a reduced lifespan. Interestingly, we observed that GEMIN5 variants disrupt a distinct set of transcripts and pathways as compared to SMA patient neurons, suggesting different molecular pathomechanisms. These findings collectively provide evidence that pathogenic variants in GEMIN5 perturb physiological functions and result in a neurodevelopmental delay and ataxia syndrome.
PMID:
33963192 | DOI:
10.1038/s41467-021-22627-w
May 11, 2021
Neurogenomics
Discriminating Bacterial and Viral Infection Using a Rapid Host Gene Expression Test
Tsalik EL, Henao R, Montgomery JL, Nawrocki JW, Aydin M, Lydon EC, Ko ER, Petzold E, Nicholson BP, Cairns CB, Glickman SW, Quackenbush E, Kingsmore SF, Jaehne AK, Rivers EP, Langley RJ, Fowler VG, McClain MT, Crisp RJ, Ginsburg GS, Burke TW, Hemmert AC, Woods CW;
Crit Care Med. 2021 Apr 28. doi: 10.1097/CCM.0000000000005085. Online ahead of print.
ABSTRACT
OBJECTIVES: Host gene expression signatures discriminate bacterial and viral infection but have not been translated to a clinical test platform. This study enrolled an independent cohort of patients to describe and validate a first-in-class host response bacterial/viral test.
DESIGN: Subjects were recruited from 2006 to 2016. Enrollment blood samples were collected in an RNA preservative and banked for later testing. The reference standard was an expert panel clinical adjudication, which was blinded to gene expression and procalcitonin results.
SETTING: Four U.S. emergency departments.
PATIENTS: Six-hundred twenty-three subjects with acute respiratory illness or suspected sepsis.
INTERVENTIONS: Forty-five-transcript signature measured on the BioFire FilmArray System (BioFire Diagnostics, Salt Lake City, UT) in ~45 minutes.
MEASUREMENTS AND MAIN RESULTS: Host response bacterial/viral test performance characteristics were evaluated in 623 participants (mean age 46 yr; 45% male) with bacterial infection, viral infection, coinfection, or noninfectious illness. Performance of the host response bacterial/viral test was compared with procalcitonin. The test provided independent probabilities of bacterial and viral infection in ~45 minutes. In the 213-subject training cohort, the host response bacterial/viral test had an area under the curve for bacterial infection of 0.90 (95% CI, 0.84-0.94) and 0.92 (95% CI, 0.87-0.95) for viral infection. Independent validation in 209 subjects revealed similar performance with an area under the curve of 0.85 (95% CI, 0.78-0.90) for bacterial infection and 0.91 (95% CI, 0.85-0.94) for viral infection. The test had 80.1% (95% CI, 73.7-85.4%) average weighted accuracy for bacterial infection and 86.8% (95% CI, 81.8-90.8%) for viral infection in this validation cohort. This was significantly better than 68.7% (95% CI, 62.4-75.4%) observed for procalcitonin (p < 0.001). An additional cohort of 201 subjects with indeterminate phenotypes (coinfection or microbiology-negative infections) revealed similar performance.
CONCLUSIONS: The host response bacterial/viral measured using the BioFire System rapidly and accurately discriminated bacterial and viral infection better than procalcitonin, which can help support more appropriate antibiotic use.
PMID:
33938716 | DOI:
10.1097/CCM.0000000000005085
May 3, 2021
Expanding the genotypic spectrum of ACTG2-related visceral myopathy
James KN, Lau M, Shayan K, Lenberg J, Mardach R, Ignacio R Jr, Halbach J, Choi L, Kumar S, Ellsworth KA.
Cold Spring Harb Mol Case Stud. 2021 Apr 21:mcs.a006085. doi: 10.1101/mcs.a006085. Online ahead of print.
ABSTRACT
Visceral myopathies (VMs) encompass a spectrum of disorders characterized by chronic disruption of gastrointestinal function, with or without urinary system involvement. Pathogenic missense variation in smooth muscle gamma-actin gene (ACTG2) is associated with autosomal dominant VM. Whole genome sequencing of an infant presenting with chronic intestinal pseudo-obstruction revealed a homozygous 187 base pair (c.589_613+163del188) deletion spanning the exon 6-intron 6 boundary within ACTG2. The patient’s clinical course was marked by prolonged hospitalizations, multiple surgeries, and intermittent total parenteral nutrition dependence. This case supports the emerging understanding of allelic heterogeneity in ACTG2-related VM, in which both homozygous and heterozygous variants in ACTG2 are associated with gastrointestinal dysfunction of similar severity and overlapped clinical presentation. Moreover, it illustrates the clinical utility of rapid whole genome sequencing, which can comprehensively and precisely detect different types of genomic variants including small deletions, leading to guidance of clinical care decisions.
PMID:33883208 | DOI:10.1101/mcs.a006085
April 23, 2021
rWGS
Rapid whole genome sequencing impacts care and resource utilization in infants with congenital heart disease
Sweeney NM, Nahas SA, Chowdhury S, Batalov S, Clark M, Caylor S, Cakici J, Nigro JJ, Ding Y, Veeraraghavan N, Hobbs C, Dimmock D, Kingsmore SF.
NPJ Genom Med. 2021 Apr 22;6(1):29. doi: 10.1038/s41525-021-00192-x.
ABSTRACT
Congenital heart disease (CHD) is the most common congenital anomaly and a major cause of infant morbidity and mortality. While morbidity and mortality are highest in infants with underlying genetic conditions, molecular diagnoses are ascertained in only ~20% of cases using widely adopted genetic tests. Furthermore, cost of care for children and adults with CHD has increased dramatically. Rapid whole genome sequencing (rWGS) of newborns in intensive care units with suspected genetic diseases has been associated with increased rate of diagnosis and a net reduction in cost of care. In this study, we explored whether the clinical utility of rWGS extends to critically ill infants with structural CHD through a retrospective review of rWGS study data obtained from inpatient infants < 1 year with structural CHD at a regional children’s hospital. rWGS diagnosed genetic disease in 46% of the enrolled infants. Moreover, genetic disease was identified five times more frequently with rWGS than microarray ± gene panel testing in 21 of these infants (rWGS diagnosed 43% versus 10% with microarray ± gene panels, p = 0.02). Molecular diagnoses ranged from syndromes affecting multiple organ systems to disorders limited to the cardiovascular system. The average daily hospital spending was lower in the time period post blood collection for rWGS compared to prior (p = 0.003) and further decreased after rWGS results (p = 0.000). The cost was not prohibitive to rWGS implementation in the care of this cohort of infants. rWGS provided timely actionable information that impacted care and there was evidence of decreased hospital spending around rWGS implementation.
PMID:
33888711 | DOI:
10.1038/s41525-021-00192-x
April 23, 2021
rWGSrWGS Efficacy
Rare deleterious mutations of HNRNP genes result in shared neurodevelopmental disorders
Gillentine MA, Wang T, Hoekzema K, Rosenfeld J, Liu P, Guo H, Kim CN, De Vries BBA, Vissers LELM, Nordenskjold M, Kvarnung M, Lindstrand A, Nordgren A, Gecz J, Iascone M, Cereda A, Scatigno A, Maitz S, Zanni G, Bertini E, Zweier C, Schuhmann S, Wiesener A, Pepper M, Panjwani H, Torti E, Abid F, Anselm I, Srivastava S, Atwal P, Bacino CA, Bhat G, Cobian K, Bird LM, Friedman J, Wright MS, Callewaert B, Petit F, Mathieu S, Afenjar A, Christensen CK, White KM, Elpeleg O, Berger I, Espineli EJ, Fagerberg C, Brasch-Andersen C, Hansen LK, Feyma T, Hughes S, Thiffault I, Sullivan B, Yan S, Keller K, Keren B, Mignot C, Kooy F, Meuwissen M, Basinger A, Kukolich M, Philips M, Ortega L, Drummond-Borg M, Lauridsen M, Sorensen K, Lehman A; CAUSES Study, Lopez-Rangel E, Levy P, Lessel D, Lotze T, Madan-Khetarpal S, Sebastian J, Vento J, Vats D, Benman LM, Mckee S, Mirzaa GM, Muss C, Pappas J, Peeters H, Romano C, Elia M, Galesi O, Simon MEH, van Gassen KLI, Simpson K, Stratton R, Syed S, Thevenon J, Palafoll IV, Vitobello A, Bournez M, Faivre L, Xia K; SPARK Consortium, Earl RK, Nowakowski T, Bernier RA, Eichler EE.
Madelyn A Gillentine
Genome Med. 2021 Apr 19;13(1):63. doi: 10.1186/s13073-021-00870-6.
ABSTRACT
BACKGROUND: With the increasing number of genomic sequencing studies, hundreds of genes have been implicated in neurodevelopmental disorders (NDDs). The rate of gene discovery far outpaces our understanding of genotype-phenotype correlations, with clinical characterization remaining a bottleneck for understanding NDDs. Most disease-associated Mendelian genes are members of gene families, and we hypothesize that those with related molecular function share clinical presentations.
METHODS: We tested our hypothesis by considering gene families that have multiple members with an enrichment of de novo variants among NDDs, as determined by previous meta-analyses. One of these gene families is the heterogeneous nuclear ribonucleoproteins (hnRNPs), which has 33 members, five of which have been recently identified as NDD genes (HNRNPK, HNRNPU, HNRNPH1, HNRNPH2, and HNRNPR) and two of which have significant enrichment in our previous meta-analysis of probands with NDDs (HNRNPU and SYNCRIP). Utilizing protein homology, mutation analyses, gene expression analyses, and phenotypic characterization, we provide evidence for variation in 12 HNRNP genes as candidates for NDDs. Seven are potentially novel while the remaining genes in the family likely do not significantly contribute to NDD risk.
RESULTS: We report 119 new NDD cases (64 de novo variants) through sequencing and international collaborations and combined with published clinical case reports. We consider 235 cases with gene-disruptive single-nucleotide variants or indels and 15 cases with small copy number variants. Three hnRNP-encoding genes reach nominal or exome-wide significance for de novo variant enrichment, while nine are candidates for pathogenic mutations. Comparison of HNRNP gene expression shows a pattern consistent with a role in cerebral cortical development with enriched expression among radial glial progenitors. Clinical assessment of probands (n = 188-221) expands the phenotypes associated with HNRNP rare variants, and phenotypes associated with variation in the HNRNP genes distinguishes them as a subgroup of NDDs.
CONCLUSIONS: Overall, our novel approach of exploiting gene families in NDDs identifies new HNRNP-related disorders, expands the phenotypes of known HNRNP-related disorders, strongly implicates disruption of the hnRNPs as a whole in NDDs, and supports that NDD subtypes likely have shared molecular pathogenesis. To date, this is the first study to identify novel genetic disorders based on the presence of disorders in related genes. We also perform the first phenotypic analyses focusing on related genes. Finally, we show that radial glial expression of these genes is likely critical during neurodevelopment. This is important for diagnostics, as well as developing strategies to best study these genes for the development of therapeutics.
PMID:
33874999 DOI:
10.1186/s13073-021-00870-6
April 20, 2021
Gene DiscoveryGenetic Neurologic DiseaseNeurogenomics
