Publications by authors named "Maria Iascone"

77 Publications

Lithium as a possible therapeutic strategy for Cornelia de Lange syndrome.

Cell Death Discov 2021 Feb 17;7(1):34. Epub 2021 Feb 17.

Department of Health Sciences, Università degli Studi di Milano, Milan, Italy.

Cornelia de Lange Syndrome (CdLS) is a rare developmental disorder affecting a multitude of organs including the central nervous system, inducing a variable neurodevelopmental delay. CdLS malformations derive from the deregulation of developmental pathways, inclusive of the canonical WNT pathway. We have evaluated MRI anomalies and behavioral and neurological clinical manifestations in CdLS patients. Importantly, we observed in our cohort a significant association between behavioral disturbance and structural abnormalities in brain structures of hindbrain embryonic origin. Considering the cumulative evidence on the cohesin-WNT-hindbrain shaping cascade, we have explored possible ameliorative effects of chemical activation of the canonical WNT pathway with lithium chloride in different models: (I) Drosophila melanogaster CdLS model showing a significant rescue of mushroom bodies morphology in the adult flies; (II) mouse neural stem cells restoring physiological levels in proliferation rate and differentiation capabilities toward the neuronal lineage; (III) lymphoblastoid cell lines from CdLS patients and healthy donors restoring cellular proliferation rate and inducing the expression of CyclinD1. This work supports a role for WNT-pathway regulation of CdLS brain and behavioral abnormalities and a consistent phenotype rescue by lithium in experimental models.
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http://dx.doi.org/10.1038/s41420-021-00414-2DOI Listing
February 2021

SPEN haploinsufficiency causes a neurodevelopmental disorder overlapping proximal 1p36 deletion syndrome with an episignature of X chromosomes in females.

Authors:
Francesca Clementina Radio Kaifang Pang Andrea Ciolfi Michael A Levy Andrés Hernández-García Lucia Pedace Francesca Pantaleoni Zhandong Liu Elke de Boer Adam Jackson Alessandro Bruselles Haley McConkey Emilia Stellacci Stefania Lo Cicero Marialetizia Motta Rosalba Carrozzo Maria Lisa Dentici Kirsty McWalter Megha Desai Kristin G Monaghan Aida Telegrafi Christophe Philippe Antonio Vitobello Margaret Au Katheryn Grand Pedro A Sanchez-Lara Joanne Baez Kristin Lindstrom Peggy Kulch Jessica Sebastian Suneeta Madan-Khetarpal Chelsea Roadhouse Jennifer J MacKenzie Berrin Monteleone Carol J Saunders July K Jean Cuevas Laura Cross Dihong Zhou Taila Hartley Sarah L Sawyer Fabíola Paoli Monteiro Tania Vertemati Secches Fernando Kok Laura E Schultz-Rogers Erica L Macke Eva Morava Eric W Klee Jennifer Kemppainen Maria Iascone Angelo Selicorni Romano Tenconi David J Amor Lynn Pais Lyndon Gallacher Peter D Turnpenny Karen Stals Sian Ellard Sara Cabet Gaetan Lesca Joset Pascal Katharina Steindl Sarit Ravid Karin Weiss Alison M R Castle Melissa T Carter Louisa Kalsner Bert B A de Vries Bregje W van Bon Marijke R Wevers Rolph Pfundt Alexander P A Stegmann Bronwyn Kerr Helen M Kingston Kate E Chandler Willow Sheehan Abdallah F Elias Deepali N Shinde Meghan C Towne Nathaniel H Robin Dana Goodloe Adeline Vanderver Omar Sherbini Krista Bluske R Tanner Hagelstrom Caterina Zanus Flavio Faletra Luciana Musante Evangeline C Kurtz-Nelson Rachel K Earl Britt-Marie Anderlid Gilles Morin Marjon van Slegtenhorst Karin E M Diderich Alice S Brooks Joost Gribnau Ruben G Boers Teresa Robert Finestra Lauren B Carter Anita Rauch Paolo Gasparini Kym M Boycott Tahsin Stefan Barakat John M Graham Laurence Faivre Siddharth Banka Tianyun Wang Evan E Eichler Manuela Priolo Bruno Dallapiccola Lisenka E L M Vissers Bekim Sadikovic Daryl A Scott Jimmy Lloyd Holder Marco Tartaglia

Am J Hum Genet 2021 Feb 9. Epub 2021 Feb 9.

Genetics and Rare Disease Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy. Electronic address:

Deletion 1p36 (del1p36) syndrome is the most common human disorder resulting from a terminal autosomal deletion. This condition is molecularly and clinically heterogeneous. Deletions involving two non-overlapping regions, known as the distal (telomeric) and proximal (centromeric) critical regions, are sufficient to cause the majority of the recurrent clinical features, although with different facial features and dysmorphisms. SPEN encodes a transcriptional repressor commonly deleted in proximal del1p36 syndrome and is located centromeric to the proximal 1p36 critical region. Here, we used clinical data from 34 individuals with truncating variants in SPEN to define a neurodevelopmental disorder presenting with features that overlap considerably with those of proximal del1p36 syndrome. The clinical profile of this disease includes developmental delay/intellectual disability, autism spectrum disorder, anxiety, aggressive behavior, attention deficit disorder, hypotonia, brain and spine anomalies, congenital heart defects, high/narrow palate, facial dysmorphisms, and obesity/increased BMI, especially in females. SPEN also emerges as a relevant gene for del1p36 syndrome by co-expression analyses. Finally, we show that haploinsufficiency of SPEN is associated with a distinctive DNA methylation episignature of the X chromosome in affected females, providing further evidence of a specific contribution of the protein to the epigenetic control of this chromosome, and a paradigm of an X chromosome-specific episignature that classifies syndromic traits. We conclude that SPEN is required for multiple developmental processes and SPEN haploinsufficiency is a major contributor to a disorder associated with deletions centromeric to the previously established 1p36 critical regions.
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http://dx.doi.org/10.1016/j.ajhg.2021.01.015DOI Listing
February 2021

A rare case of pediatric cardiomyopathy: Alström syndrome identified by gene panel analysis.

Clin Case Rep 2020 Dec 27;8(12):3369-3373. Epub 2020 Oct 27.

Cardiology Unit Meyer Children's Hospital Florence Italy.

Genetic investigation of early-onset Dilatative cardiomyopathy phenotype, including molecular autopsy, is the key to appropriate recognition and management of rare etiologies and atypical presentations and to offer genetic counseling to the family.
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http://dx.doi.org/10.1002/ccr3.3327DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7752570PMC
December 2020

Defining the genotypic and phenotypic spectrum of X-linked MSL3-related disorder.

Genet Med 2021 Feb 11;23(2):384-395. Epub 2020 Nov 11.

Institute of Human Genetics, Technical University Munich, Munich, Germany.

Purpose: We sought to delineate the genotypic and phenotypic spectrum of female and male individuals with X-linked, MSL3-related disorder (Basilicata-Akhtar syndrome).

Methods: Twenty-five individuals (15 males, 10 females) with causative variants in MSL3 were ascertained through exome or genome sequencing at ten different sequencing centers.

Results: We identified multiple variant types in MSL3 (ten nonsense, six frameshift, four splice site, three missense, one in-frame-deletion, one multi-exon deletion), most proven to be de novo, and clustering in the terminal eight exons suggesting that truncating variants in the first five exons might be compensated by an alternative MSL3 transcript. Three-dimensional modeling of missense and splice variants indicated that these have a deleterious effect. The main clinical findings comprised developmental delay and intellectual disability ranging from mild to severe. Autism spectrum disorder, muscle tone abnormalities, and macrocephaly were common as well as hearing impairment and gastrointestinal problems. Hypoplasia of the cerebellar vermis emerged as a consistent magnetic resonance image (MRI) finding. Females and males were equally affected. Using facial analysis technology, a recognizable facial gestalt was determined.

Conclusion: Our aggregated data illustrate the genotypic and phenotypic spectrum of X-linked, MSL3-related disorder (Basilicata-Akhtar syndrome). Our cohort improves the understanding of disease related morbidity and allows us to propose detailed surveillance guidelines for affected individuals.
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http://dx.doi.org/10.1038/s41436-020-00993-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862064PMC
February 2021

Congenital Muscular Mitral-Aortic Discontinuity Identified in Patients With Obstructive Hypertrophic Cardiomyopathy.

J Am Coll Cardiol 2020 11;76(19):2238-2247

Laboratorio di Genetica Medica, Ospedale Papa Giovanni XXIII, Bergamo, Italy.

Background: The mitral valve is often structurally abnormal in hypertrophic cardiomyopathy (HCM). However, the mechanisms responsible for these abnormalities remain controversial. In 2016 we identified, at myectomy, muscular mitral-aortic discontinuity in 5 young patients with obstructive HCM.

Objectives: This study sought to confirm our preliminary findings and assess the prevalence of muscular mitral-aortic discontinuity in obstructive HCM.

Methods: At our center, from January 2017 to April 2018, the area between the anterior mitral leaflet and aortic valve was inspected at myectomy in 106 consecutive patients with HCM.

Results: Muscular mitral-aortic discontinuity was identified in 28 (26%) patients and was significantly more common in younger than older patients (age 39 ± 13 years vs. 58 ± 11 years; p < 0.001). Muscular discontinuity was present in each of 6 patients aged <30 years but only 1 (2.7%) of 37 aged ≥60 years. Pathogenic sarcomere mutations were identified in 22 (79%) of 28 patients with and 24 (31%) of 78 without discontinuity (p < 0.001) and were associated with discontinuity independently of age (p = 0.021). Discontinuity mean length was 7.3 mm and was inversely related to age (p = 0.022). At echocardiography, the anterior mitral leaflet was longer in patients with than those without discontinuity (34 ± 4 mm vs. 29 ± 5 mm; p < 0.001).

Conclusions: We report, for the first time, muscular mitral-aortic discontinuity in HCM. At myectomy, a long muscular discontinuity displaced the anterior mitral leaflet toward the apex in most young patients, was significantly associated with sarcomere mutations independent of age, and was extremely uncommon in older patients. These findings suggest that a long muscular mitral-aortic discontinuity could predispose to the development of outflow obstruction in young patients with sarcomere mutations.
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http://dx.doi.org/10.1016/j.jacc.2020.09.534DOI Listing
November 2020

Clinical Profile of Cardiac Involvement in Danon Disease: A Multicenter European Registry.

Circ Genom Precis Med 2020 Dec 5;13(6):e003117. Epub 2020 Nov 5.

Leviev Heart Center, Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Israel (D.L., Y.W., M.A.).

Background: The X-linked Danon disease manifests by severe cardiomyopathy, myopathy, and neuropsychiatric problems. We designed this registry to generate a comprehensive picture of clinical presentations and outcome of patients with Danon disease in cardiomyopathy centers throughout Europe.

Methods: Clinical and genetic data were collected in 16 cardiology centers from 8 European countries.

Results: The cohort comprised 30 male and 27 female patients. The age at diagnosis was birth to 42 years in men and 2 to 65 in women. Cardiac involvement was observed in 96%. Extracardiac manifestations were prominent in men but not in women. Left ventricular (LV) hypertrophy was reported in 73% of male and 74% of female patients. LV systolic dysfunction was reported in 40% of men (who had LV ejection fraction, 34±11%) and 59% of women (LV ejection fraction, 28±13%). The risk of arrhythmia and heart failure was comparable among sexes. The age of first heart failure hospitalization was lower in men (18±6 versus 28±17 years; <0.003). Heart failure was the leading cause of death (10 of 17; 59%), and LV systolic dysfunction predicted an adverse outcome. Eight men and 8 women (28%) underwent heart transplantation or received an LV assist device. Our cohort suggests better prognosis of female compared with male heart transplant recipients.

Conclusions: Danon disease presents earlier in men than in women and runs a malignant course in both sexes, due to cardiac complications. Cardiomyopathy features, heart failure and arrhythmia, are similar among the sexes. Clinical diagnosis and management is extremely challenging in women due to phenotypic diversity and the absence of extracardiac manifestations.
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http://dx.doi.org/10.1161/CIRCGEN.120.003117DOI Listing
December 2020

A novel HIST1HE pathogenic variant in a girl with macrocephaly and intellectual disability: a new case and review of literature.

Clin Dysmorphol 2021 Jan;30(1):39-43

Pediatric Unit, A.S.S.T. Lariana Sant'Anna Hospital, San Fermo della Battaglia, Como.

Pathogenic variants of HIST1H1Egene have recently been associated with a condition known as Rahman syndrome, characterized by overgrowth, intellectual disability and nonspecific dysmorphic features (high hairline, full cheeks, wide nasal bridge). Wide clinical variability is reported, especially regarding the level of neurodevelopment delay and intellectual disability. We report a 10-year-old girl with macrocephaly and global developmental delay, in whom a novel heterozygous variant in the HIST1H1Egene [c.392_395dup (p.Gly133fs)] was discovered, but involving the same C-terminal domain-protein domain reported previously. Comparing the clinical data of our patient with those previously described, a 'core phenotype' with macrocephaly, psychomotor delay/intellectual disability and mild facial dysmorphisms seems evident.
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http://dx.doi.org/10.1097/MCD.0000000000000352DOI Listing
January 2021

Epilepsy and movement disorders in CDG: Report on the oldest-known MOGS-CDG patient.

Am J Med Genet A 2021 01 15;185(1):219-222. Epub 2020 Oct 15.

Child Neuropsychiatry, Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona, Italy.

Congenital glycosylation disorders (CDG) are inherited metabolic diseases due to defective glycoprotein and glycolipid glycan assembly and attachment. MOGS-CDG is a rare disorder with seven patients from five families reported worldwide. We report on a 19-year-old girl with MOGS-CDG. At birth she presented facial dysmorphism, marked hypotonia, and drug-resistant tonic seizures. In the following months, her motility was strongly limited by dystonia, with forced posture of the head and of both hands. She showed a peculiar hyperkinetic movement disorder with a rhythmic and repetitive pattern repeatedly documented on EEG-polygraphy recordings. Brain MRI showed progressive cortical and subcortical atrophy. Epileptic spasms appeared in first months and ceased by the age of 7 years, while tonic seizures were still present at last assessment (19 years). We report the oldest-known MOGS-CDG patient and broaden the neurological phenotype of this CDG.
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http://dx.doi.org/10.1002/ajmg.a.61916DOI Listing
January 2021

Absent B cells, agammaglobulinemia, and hypertrophic cardiomyopathy in folliculin-interacting protein 1 deficiency.

Blood 2021 Jan;137(4):493-499

Pediatric Hematology Department, Fondazione Monza e Brianza per il Bambino e la sua Mamma (MBBM), University of Milano Bicocca, Monza, Italy.

Agammaglobulinemia is the most profound primary antibody deficiency that can occur due to an early termination of B-cell development. We here investigated 3 novel patients, including the first known adult, from unrelated families with agammaglobulinemia, recurrent infections, and hypertrophic cardiomyopathy (HCM). Two of them also presented with intermittent or severe chronic neutropenia. We identified homozygous or compound-heterozygous variants in the gene for folliculin interacting protein 1 (FNIP1), leading to loss of the FNIP1 protein. B-cell metabolism, including mitochondrial numbers and activity and phosphatidylinositol 3-kinase/AKT pathway, was impaired. These defects recapitulated the Fnip1-/- animal model. Moreover, we identified either uniparental disomy or copy-number variants (CNVs) in 2 patients, expanding the variant spectrum of this novel inborn error of immunity. The results indicate that FNIP1 deficiency can be caused by complex genetic mechanisms and support the clinical utility of exome sequencing and CNV analysis in patients with broad phenotypes, including agammaglobulinemia and HCM. FNIP1 deficiency is a novel inborn error of immunity characterized by early and severe B-cell development defect, agammaglobulinemia, variable neutropenia, and HCM. Our findings elucidate a functional and relevant role of FNIP1 in B-cell development and metabolism and potentially neutrophil activity.
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http://dx.doi.org/10.1182/blood.2020006441DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7845007PMC
January 2021

Phenotypic spectrum of short-chain enoyl-Coa hydratase-1 (ECHS1) deficiency.

Eur J Paediatr Neurol 2020 Sep 29;28:151-158. Epub 2020 Jul 29.

Pediatric Neurology Unit, V. Buzzi Children's Hospital, Milan, Italy. Electronic address:

Introduction: ECHS1 encodes for short-chain enoyl-CoA hydratase, a key component in b-oxidation. This enzyme is also involved in the isoleucine and valine catabolic pathways. The literature contains reports of scattered cases of ECHS1 mutation, which show a wide clinical spectrum of presentation. Despite that the clinical spectrum of the disease has not been defined so far due to the absence of previous systematic reviews and descriptions of large series of patients.

Methods: We performed a systematic literature review of so far reported ECHS1 mutated patients and we reported two additional cases. We pointed out clinical and neuroradiological features of all patients.

Results: 45 patients were included in the analysis. Based on clinical and neuroradiological feature we were able to distinguish four main phenotypes of ECHS1deficiency: a severe neonatal presentation with a rapid and fatal course and significant white matter abnormalities; a severe infantile variant with slower neurological deterioration, developmental delay, pyramidal and extrapyramidal signs, optic atrophy, feeding difficulties, and degeneration of the deep gray nuclei; a slowly progressive infantile form, qualitatively similar to the previous phenotype, but less severe with mainly basal ganglia involvement; and a final phenotype, present in only few cases, characterized by paroxysmal exercise-induced dystonic attacks, normal neurological examination between these episodes, and isolated pallidal degeneration on MRI.

Interpretation: ECHS1 mutations cause metabolic encephalopathy with a wide range of clinical presentations that can be grouped into four main phenotypes, each with a distinct profile in terms of severity on clinical presentation, disease course and MRI involvement.
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http://dx.doi.org/10.1016/j.ejpn.2020.07.007DOI Listing
September 2020

Biallelic MADD variants cause a phenotypic spectrum ranging from developmental delay to a multisystem disorder.

Brain 2020 08;143(8):2437-2453

Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.

In pleiotropic diseases, multiple organ systems are affected causing a variety of clinical manifestations. Here, we report a pleiotropic disorder with a unique constellation of neurological, endocrine, exocrine, and haematological findings that is caused by biallelic MADD variants. MADD, the mitogen-activated protein kinase (MAPK) activating death domain protein, regulates various cellular functions, such as vesicle trafficking, activity of the Rab3 and Rab27 small GTPases, tumour necrosis factor-α (TNF-α)-induced signalling and prevention of cell death. Through national collaboration and GeneMatcher, we collected 23 patients with 21 different pathogenic MADD variants identified by next-generation sequencing. We clinically evaluated the series of patients and categorized the phenotypes in two groups. Group 1 consists of 14 patients with severe developmental delay, endo- and exocrine dysfunction, impairment of the sensory and autonomic nervous system, and haematological anomalies. The clinical course during the first years of life can be potentially fatal. The nine patients in Group 2 have a predominant neurological phenotype comprising mild-to-severe developmental delay, hypotonia, speech impairment, and seizures. Analysis of mRNA revealed multiple aberrant MADD transcripts in two patient-derived fibroblast cell lines. Relative quantification of MADD mRNA and protein in fibroblasts of five affected individuals showed a drastic reduction or loss of MADD. We conducted functional tests to determine the impact of the variants on different pathways. Treatment of patient-derived fibroblasts with TNF-α resulted in reduced phosphorylation of the extracellular signal-regulated kinases 1 and 2, enhanced activation of the pro-apoptotic enzymes caspase-3 and -7 and increased apoptosis compared to control cells. We analysed internalization of epidermal growth factor in patient cells and identified a defect in endocytosis of epidermal growth factor. We conclude that MADD deficiency underlies multiple cellular defects that can be attributed to alterations of TNF-α-dependent signalling pathways and defects in vesicular trafficking. Our data highlight the multifaceted role of MADD as a signalling molecule in different organs and reveal its physiological role in regulating the function of the sensory and autonomic nervous system and endo- and exocrine glands.
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http://dx.doi.org/10.1093/brain/awaa204DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7447524PMC
August 2020

De Novo Variants in CNOT1, a Central Component of the CCR4-NOT Complex Involved in Gene Expression and RNA and Protein Stability, Cause Neurodevelopmental Delay.

Am J Hum Genet 2020 07 17;107(1):164-172. Epub 2020 Jun 17.

Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, PO Box 9101, 6500 HB Nijmegen, the Netherlands.

CNOT1 is a member of the CCR4-NOT complex, which is a master regulator, orchestrating gene expression, RNA deadenylation, and protein ubiquitination. We report on 39 individuals with heterozygous de novo CNOT1 variants, including missense, splice site, and nonsense variants, who present with a clinical spectrum of intellectual disability, motor delay, speech delay, seizures, hypotonia, and behavioral problems. To link CNOT1 dysfunction to the neurodevelopmental phenotype observed, we generated variant-specific Drosophila models, which showed learning and memory defects upon CNOT1 knockdown. Introduction of human wild-type CNOT1 was able to rescue this phenotype, whereas mutants could not or only partially, supporting our hypothesis that CNOT1 impairment results in neurodevelopmental delay. Furthermore, the genetic interaction with autism-spectrum genes, such as ASH1L, DYRK1A, MED13, and SHANK3, was impaired in our Drosophila models. Molecular characterization of CNOT1 variants revealed normal CNOT1 expression levels, with both mutant and wild-type alleles expressed at similar levels. Analysis of protein-protein interactions with other members indicated that the CCR4-NOT complex remained intact. An integrated omics approach of patient-derived genomics and transcriptomics data suggested only minimal effects on endonucleolytic nonsense-mediated mRNA decay components, suggesting that de novo CNOT1 variants are likely haploinsufficient hypomorph or neomorph, rather than dominant negative. In summary, we provide strong evidence that de novo CNOT1 variants cause neurodevelopmental delay with a wide range of additional co-morbidities. Whereas the underlying pathophysiological mechanism warrants further analysis, our data demonstrate an essential and central role of the CCR4-NOT complex in human brain development.
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http://dx.doi.org/10.1016/j.ajhg.2020.05.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7332645PMC
July 2020

Missense NR2F1 variant in monozygotic twins affected with the Bosch-Boonstra-Schaaf optic atrophy syndrome.

Mol Genet Genomic Med 2020 07 15;8(7):e1278. Epub 2020 May 15.

Department of Medicine (DAME), University of Udine, Udine, Italy.

Background: The Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is an autosomal-dominant disorder (OMIM615722) mostly characterized by optic atrophy and/or hypoplasia, mild intellectual disability, hypotonia, seizures/infantile epilepsy. This disorder is caused by loss-of-function alterations of NR2F1 (i.e., either whole gene deletions or single nucleotide variants) and, to date, 40 patients have been identified with deletions or mutations in this gene. Here we describe two monozygotic twins harboring a de novo missense variant in the DNA-binding domain of NR2F1 (c.313G>A, p.Gly105Ser), with well-characterized features associated to BBSOAS.

Methods: Patients' DNA was analyzed by exome sequencing identifying the missense variant c.313G>A in NR2F1 (NM_005654.4). Furthermore, molecular modeling was performed to evaluate putative differences in DNA binding between wild-type and mutated NR2F1.

Results: The missense variant is predicted to be likely pathogenetic following the ACMG (American College of Medical Genetics and Genomics)/AMP (Association for Molecular Pathology) guidelines. Indeed, dynamic simulation experiments highlighted that the Gly105Ser substitution let the formation of a hydrogen bond between the S105 side chain and R142 and a base (G5) of the DNA sequence, allowing us to hypothesize that the G105 residue might be evolutionary conserved due to the absence of a side chain, besides glycine conformational features. Therefore, the G105S variation seems to cause a stiffening and a possible deformation in the protein-DNA complex due to the interaction of residues R142-S105 and G5 on the DNA, compared to the wild-type.

Conclusion: In summary, we described two monozygotic twins harboring a novel Gly105Ser mutation in NR2F1 DNA binding domain, displaying the classical phenotype of BBSOAS-affected patients. Our computational data suggest a dominant negative effect of this newly characterized missense variant. To date, this is the first genetic report analyzing in silico structural consequences of NR2F1 Gly105Ser substitution.
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http://dx.doi.org/10.1002/mgg3.1278DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7336747PMC
July 2020

Phenotypic spectrum and transcriptomic profile associated with germline variants in TRAF7.

Authors:
Laura Castilla-Vallmanya Kaja K Selmer Clémantine Dimartino Raquel Rabionet Bernardo Blanco-Sánchez Sandra Yang Margot R F Reijnders Antonie J van Essen Myriam Oufadem Magnus D Vigeland Barbro Stadheim Gunnar Houge Helen Cox Helen Kingston Jill Clayton-Smith Jeffrey W Innis Maria Iascone Anna Cereda Sara Gabbiadini Wendy K Chung Victoria Sanders Joel Charrow Emily Bryant John Millichap Antonio Vitobello Christel Thauvin Frederic Tran Mau-Them Laurence Faivre Gaetan Lesca Audrey Labalme Christelle Rougeot Nicolas Chatron Damien Sanlaville Katherine M Christensen Amelia Kirby Raymond Lewandowski Rachel Gannaway Maha Aly Anna Lehman Lorne Clarke Luitgard Graul-Neumann Christiane Zweier Davor Lessel Bernarda Lozic Ingvild Aukrust Ryan Peretz Robert Stratton Thomas Smol Anne Dieux-Coëslier Joanna Meira Elizabeth Wohler Nara Sobreira Erin M Beaver Jennifer Heeley Lauren C Briere Frances A High David A Sweetser Melissa A Walker Catherine E Keegan Parul Jayakar Marwan Shinawi Wilhelmina S Kerstjens-Frederikse Dawn L Earl Victoria M Siu Emma Reesor Tony Yao Robert A Hegele Olena M Vaske Shannon Rego Kevin A Shapiro Brian Wong Michael J Gambello Marie McDonald Danielle Karlowicz Roberto Colombo Alessandro Serretti Lynn Pais Anne O'Donnell-Luria Alison Wray Simon Sadedin Belinda Chong Tiong Y Tan John Christodoulou Susan M White Anne Slavotinek Deborah Barbouth Dayna Morel Swols Mélanie Parisot Christine Bole-Feysot Patrick Nitschké Véronique Pingault Arnold Munnich Megan T Cho Valérie Cormier-Daire Susanna Balcells Stanislas Lyonnet Daniel Grinberg Jeanne Amiel Roser Urreizti Christopher T Gordon

Genet Med 2020 Jul 7;22(7):1215-1226. Epub 2020 May 7.

Laboratory of embryology and genetics of human malformations, Institut National de la Santé et de la Recherche Médicale (INSERM) UMR 1163, Institut Imagine, Paris, France.

Purpose: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts.

Methods: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts.

Results: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts.

Conclusion: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies.
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http://dx.doi.org/10.1038/s41436-020-0792-7DOI Listing
July 2020

Familial Sleep Disorders in Unknown Genetic Syndrome.

J Pediatr Genet 2020 Jun 21;9(2):132-136. Epub 2019 Oct 21.

Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.

Sleep-disordered breathing (SDB) is common in children, especially in those with congenital or genetic diseases. The factors involved include obstructive sleep apnea, disrupted rapid eye movement sleep, and central hypoventilation. Diagnosing and treating SDB in these children have a positive impact on the quality of life of them and their families, reducing the risk of both further impairment of cognitive abilities and cardiopulmonary complications. We report a familial case of SDB with central hypoventilation, in which identification of the disorder in the younger sister led to the unfortunately late diagnosis and treatment of the same condition in the older sister.
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http://dx.doi.org/10.1055/s-0039-1698808DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7183398PMC
June 2020

HNRNPH1-related syndromic intellectual disability: Seven additional cases suggestive of a distinct syndromic neurodevelopmental syndrome.

Clin Genet 2020 07 15;98(1):91-98. Epub 2020 May 15.

Department of Human and Molecular Genetics, Clinical Genetics Services, VCU Health, Richmond, Virginia, USA.

Pathogenic variants in HNRNPH1 were first reported in 2018. The reported individual, a 13 year old boy with a c.616C>T (p.R206W) variant in the HNRNPH1 gene, was noted to have overlapping symptoms with those observed in HNRNPH2-related X-linked intellectual disability, Bain type (MRXSB), specifically intellectual disability and dysmorphic features. While HNRNPH1 variants were initially proposed to represent an autosomal cause of MRXSB, we report an additional seven cases which identify phenotypic differences from MRXSB. Patients with HNRNPH1 pathogenic variants diagnosed via WES were identified using clinical networks and GeneMatcher. Features unique to individuals with HNRNPH1 variants include distinctive dysmorphic facial features; an increased incidence of congenital anomalies including cranial and brain abnormalities, genitourinary malformations, and palate abnormalities; increased incidence of ophthalmologic abnormalities; and a decreased incidence of epilepsy and cardiac defects compared to those with MRXSB. This suggests that pathogenic variants in HNRNPH1 result in a related, but distinct syndromic cause of intellectual disability from MRXSB, which we refer to as HNRNPH1-related syndromic intellectual disability.
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http://dx.doi.org/10.1111/cge.13765DOI Listing
July 2020

DNA Methylation Signature for EZH2 Functionally Classifies Sequence Variants in Three PRC2 Complex Genes.

Am J Hum Genet 2020 05 2;106(5):596-610. Epub 2020 Apr 2.

Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada; Department of Pediatrics, University of Toronto, Toronto, ON M5S 1A1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A1, Canada; Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Electronic address:

Weaver syndrome (WS), an overgrowth/intellectual disability syndrome (OGID), is caused by pathogenic variants in the histone methyltransferase EZH2, which encodes a core component of the Polycomb repressive complex-2 (PRC2). Using genome-wide DNA methylation (DNAm) data for 187 individuals with OGID and 969 control subjects, we show that pathogenic variants in EZH2 generate a highly specific and sensitive DNAm signature reflecting the phenotype of WS. This signature can be used to distinguish loss-of-function from gain-of-function missense variants and to detect somatic mosaicism. We also show that the signature can accurately classify sequence variants in EED and SUZ12, which encode two other core components of PRC2, and predict the presence of pathogenic variants in undiagnosed individuals with OGID. The discovery of a functionally relevant signature with utility for diagnostic classification of sequence variants in EZH2, EED, and SUZ12 supports the emerging paradigm shift for implementation of DNAm signatures into diagnostics and translational research.
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http://dx.doi.org/10.1016/j.ajhg.2020.03.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7212265PMC
May 2020

PIGW-related glycosylphosphatidylinositol deficiency: Description of a new patient and review of the literature.

Am J Med Genet A 2020 06 21;182(6):1477-1482. Epub 2020 Mar 21.

Child Neuropsychiatry Unit-Epilepsy Center, ASST Santi Paolo e Carlo, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Milan, Italy.

Inherited glycosylphosphatidylinositol (GPI) deficiencies are a group of clinically and genetically heterogeneous conditions belonging to the congenital disorders of glycosylation. PIGW is involved in GPI biosynthesis and modification, and biallelic pathogenic variants in this gene cause autosomal recessive GPI biosynthesis defect 11. Only five patients and two fetuses have been reported in the literature thus far. Here we describe a new patient with a novel homozygous missense variant in PIGW, who presented with hypotonia, severe intellectual disability, early-onset epileptic seizures, brain abnormalities, nystagmus, hand stereotypies, recurrent respiratory infections, distinctive facial features, and hyperphosphatasia. Our report expands the phenotype of GPI biosynthesis defect 11 to include stereotypies and recurrent respiratory infections. A detailed and long-term analysis of the electroclinical characteristics and review of the literature suggest that early-onset epileptic seizures are a key manifestation of GPI biosynthesis defect 11. West syndrome and focal-onset epileptic seizures are the most common seizure types, and the fronto-temporal regions may be the most frequently involved areas in these patients.
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http://dx.doi.org/10.1002/ajmg.a.61555DOI Listing
June 2020

De novo EIF2AK1 and EIF2AK2 Variants Are Associated with Developmental Delay, Leukoencephalopathy, and Neurologic Decompensation.

Am J Hum Genet 2020 04 19;106(4):570-583. Epub 2020 Mar 19.

Department of Pediatrics, Baylor College of Medicine (BCM), Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA; Division of Neurology and Developmental Neuroscience, Department of Pediatrics, BCM, Houston, TX 77030, USA; Department of Molecular and Human Genetics, BCM, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA; Program in Development, Disease Models, and Therapeutics, BCM, Houston, TX 77030, USA; Department of Neuroscience, BCM, Houston, TX 77030, USA; McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX 77030, USA. Electronic address:

EIF2AK1 and EIF2AK2 encode members of the eukaryotic translation initiation factor 2 alpha kinase (EIF2AK) family that inhibits protein synthesis in response to physiologic stress conditions. EIF2AK2 is also involved in innate immune response and the regulation of signal transduction, apoptosis, cell proliferation, and differentiation. Despite these findings, human disorders associated with deleterious variants in EIF2AK1 and EIF2AK2 have not been reported. Here, we describe the identification of nine unrelated individuals with heterozygous de novo missense variants in EIF2AK1 (1/9) or EIF2AK2 (8/9). Features seen in these nine individuals include white matter alterations (9/9), developmental delay (9/9), impaired language (9/9), cognitive impairment (8/9), ataxia (6/9), dysarthria in probands with verbal ability (6/9), hypotonia (7/9), hypertonia (6/9), and involuntary movements (3/9). Individuals with EIF2AK2 variants also exhibit neurological regression in the setting of febrile illness or infection. We use mammalian cell lines and proband-derived fibroblasts to further confirm the pathogenicity of variants in these genes and found reduced kinase activity. EIF2AKs phosphorylate eukaryotic translation initiation factor 2 subunit 1 (EIF2S1, also known as EIF2α), which then inhibits EIF2B activity. Deleterious variants in genes encoding EIF2B proteins cause childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM), a leukodystrophy characterized by neurologic regression in the setting of febrile illness and other stressors. Our findings indicate that EIF2AK2 missense variants cause a neurodevelopmental syndrome that may share phenotypic and pathogenic mechanisms with CACH/VWM.
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http://dx.doi.org/10.1016/j.ajhg.2020.02.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7118694PMC
April 2020

Double homozygosity in CEP57 and DYNC2H1 genes detected by WES: Composite or expanded phenotype?

Mol Genet Genomic Med 2020 03 14;8(3):e1064. Epub 2020 Jan 14.

Laboratorio di Genetica Medica, ASST Papa Giovanni XXIII, Bergamo, Italy.

Background: In the last few years trio-whole exome sequencing (WES) analysis has demonstrated its potential in obtaining genetic diagnoses even in nonspecific clinical pictures and in atypical presentations of known diseases. Moreover WES allows the detection of variants in multiple genes causing different genetic conditions in a single patient, in about 5% of cases. The resulting phenotype may be clinically discerned as variability in the expression of a known phenotype, or as a new unreported syndromic condition.

Methods: Trio-WES was performed on a 4-month-old baby with a complex clinical presentation characterized by skeletal anomalies, congenital heart malformation, congenital hypothyroidism, generalized venous and arterial hypoplasia, and recurrent infections.

Results: WES detected two different homozygous variants, one in CEP57, the gene responsible for mosaic variegated aneuploidy syndrome 2, the other in DYNC2H1, the main gene associated with short-rib thoracic dysplasia.

Conclusion: The contribution of these two different genetic causes in determining the phenotype of our patient is discussed, including some clinical signs not explained by the detected variants. The report then highlights the role of WES in providing complete and fast diagnosis in patients with complex presentations of rare genetic syndromes, with important implications in the assessment of recurrence risk.
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http://dx.doi.org/10.1002/mgg3.1064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057129PMC
March 2020

Severe Late-Onset Fabry Cardiomyopathy Unmasked by a Multimodality Imaging Approach.

Circ Cardiovasc Imaging 2019 11 21;12(11):e009709. Epub 2019 Oct 21.

Cardiology Department (I.-S.V., A.O.C., D.V., R.C.R.), University and Emergency Hospital, Bucharest, Romania.

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http://dx.doi.org/10.1161/CIRCIMAGING.119.009709DOI Listing
November 2019

ATP8A2-related disorders as recessive cerebellar ataxia.

J Neurol 2020 Jan 14;267(1):203-213. Epub 2019 Oct 14.

Laboratoire de Génétique de Maladies Rares EA7402, Institut Universitaire de Recherche Clinique, Université de Montpellier, CHU Montpellier, 640 av. Doyen G. Giraud CEDEX 5, 34295, Montpellier, France.

ATP8A2-related disorders are autosomal recessive conditions that associate encephalopathy with or without hypotonia, psychomotor delay, abnormal movements, chorea, tremor, optic atrophy and cerebellar atrophy (CARMQ4). Through a multi-centric collaboration, we identified six point mutations (one splice site and five missense mutations) involving ATP8A2 in six individuals from five families. Two patients from one family with the homozygous p.Gly585Val mutation had a milder presentation without encephalopathy. Expression and functional studies of the missense mutations demonstrated that protein levels of four of the five missense variants were very low and lacked phosphatidylserine-activated ATPase activity. One variant p.Ile215Leu, however, expressed at normal levels and displayed phospholipid-activated ATPase activity similar to the non-mutated protein. We therefore expand for the first time the phenotype related to ATP8A2 mutations to less severe forms characterized by cerebellar ataxia without encephalopathy and suggest that ATP8A2 should be analyzed for all cases of syndromic or non-syndromic recessive or sporadic ataxia.
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http://dx.doi.org/10.1007/s00415-019-09579-4DOI Listing
January 2020

A novel nonsense and inactivating variant of ST3GAL3 in two infant siblings suffering severe epilepsy and expressing circulating CA19.9.

Glycobiology 2020 01;30(2):95-104

Department of Medicine and Surgery (DMC), University of Insubria, via JH Dunant 5, 21100 Varese, Italy.

Three missense variants of ST3GAL3 are known to be responsible for a congenital disorder of glycosylation determining a neurodevelopmental disorder (intellectual disability/epileptic encephalopathy). Here we report a novel nonsense variant, p.Y220*, in two dichorionic infant twins presenting a picture of epileptic encephalopathy with impaired neuromotor development. Upon expression in HEK-293T cells, the variant appears totally devoid of enzymatic activity in vitro, apparently accumulated with respect to the wild-type or the missense variants, as detected by western blot, and in large part properly localized in the Golgi apparatus, as assessed by confocal microscopy. Both patients were found to efficiently express the CA19.9 antigen in the serum despite the total loss of ST3GAL3 activity, which thus appears replaceable from other ST3GALs in the synthesis of the sialyl-Lewis a epitope. Kinetic studies of ST3GAL3 revealed a strong preference for lactotetraosylceramide as acceptor and gangliotetraosylceramide was also efficiently utilized in vitro. Moreover, the p.A13D missense variant, the one maintaining residual sialyltransferase activity, was found to have much lower affinity for all suitable substrates than the wild-type enzyme with an overall catalytic efficiency almost negligible. Altogether the present data suggest that the apparent redundancy of ST3GALs deduced from knock-out mouse models only partially exists in humans. In fact, our patients lacking ST3GAL3 activity synthesize the CA19.9 epitope sialyl-Lewis a, but not all glycans necessary for fine brain functions, where the role of minor gangliosides deserves further attention.
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http://dx.doi.org/10.1093/glycob/cwz079DOI Listing
January 2020

Dual genetic diagnoses: neurofibromatosis type 1 and KBG syndrome.

Clin Dysmorphol 2020 Apr;29(2):101-103

Pediatric Department, ASST Lariana, Sant'Anna General Hospital, Como, Italy.

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http://dx.doi.org/10.1097/MCD.0000000000000296DOI Listing
April 2020

Human iPSC modelling of a familial form of atrial fibrillation reveals a gain of function of If and ICaL in patient-derived cardiomyocytes.

Cardiovasc Res 2020 05;116(6):1147-1160

Department of Molecular and Translational Medicine, cFRU lab, Università degli Studi di Brescia, viale Europa 11, 25123 Brescia, Italy.

Aims: Atrial fibrillation (AF) is the most common type of cardiac arrhythmias, whose incidence is likely to increase with the aging of the population. It is considered a progressive condition, frequently observed as a complication of other cardiovascular disorders. However, recent genetic studies revealed the presence of several mutations and variants linked to AF, findings that define AF as a multifactorial disease. Due to the complex genetics and paucity of models, molecular mechanisms underlying the initiation of AF are still poorly understood. Here we investigate the pathophysiological mechanisms of a familial form of AF, with particular attention to the identification of putative triggering cellular mechanisms, using patient's derived cardiomyocytes (CMs) differentiated from induced pluripotent stem cells (iPSCs).

Methods And Results: Here we report the clinical case of three siblings with untreatable persistent AF whose whole-exome sequence analysis revealed several mutated genes. To understand the pathophysiology of this multifactorial form of AF we generated three iPSC clones from two of these patients and differentiated these cells towards the cardiac lineage. Electrophysiological characterization of patient-derived CMs (AF-CMs) revealed that they have higher beating rates compared to control (CTRL)-CMs. The analysis showed an increased contribution of the If and ICaL currents. No differences were observed in the repolarizing current IKr and in the sarcoplasmic reticulum calcium handling. Paced AF-CMs presented significantly prolonged action potentials and, under stressful conditions, generated both delayed after-depolarizations of bigger amplitude and more ectopic beats than CTRL cells.

Conclusions: Our results demonstrate that the common genetic background of the patients induces functional alterations of If and ICaL currents leading to a cardiac substrate more prone to develop arrhythmias under demanding conditions. To our knowledge this is the first report that, using patient-derived CMs differentiated from iPSC, suggests a plausible cellular mechanism underlying this complex familial form of AF.
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http://dx.doi.org/10.1093/cvr/cvz217DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7177512PMC
May 2020

Rare presentation and wide intrafamilial variability of Fabry disease: A case report and review of the literature.

Anatol J Cardiol 2019 Sep;22(3):154-158

Department of Cardiology, The Expert Center for Rare Genetic Cardiovascular Diseases, Euroecolab, Emergency Institute for Cardiovascular Diseases 'Prof. Dr. C.C. Iliescu'; Bucharest-Romania.

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http://dx.doi.org/10.14744/AnatolJCardiol.2019.47969DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6735429PMC
September 2019

Phenotype delineation of ZNF462 related syndrome.

Am J Med Genet A 2019 10 30;179(10):2075-2082. Epub 2019 Jul 30.

Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland.

Zinc finger protein 462 (ZNF462) is a relatively newly discovered vertebrate specific protein with known critical roles in embryonic development in animal models. Two case reports and a case series study have described the phenotype of 10 individuals with ZNF462 loss of function variants. Herein, we present 14 new individuals with loss of function variants to the previous studies to delineate the syndrome of loss of function in ZNF462. Collectively, these 24 individuals present with recurring phenotypes that define a multiple congenital anomaly syndrome. Most have some form of developmental delay (79%) and a minority has autism spectrum disorder (33%). Characteristic facial features include ptosis (83%), down slanting palpebral fissures (58%), exaggerated Cupid's bow/wide philtrum (54%), and arched eyebrows (50%). Metopic ridging or craniosynostosis was found in a third of study participants and feeding problems in half. Other phenotype characteristics include dysgenesis of the corpus callosum in 25% of individuals, hypotonia in half, and structural heart defects in 21%. Using facial analysis technology, a computer algorithm applying deep learning was able to accurately differentiate individuals with ZNF462 loss of function variants from individuals with Noonan syndrome and healthy controls. In summary, we describe a multiple congenital anomaly syndrome associated with haploinsufficiency of ZNF462 that has distinct clinical characteristics and facial features.
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http://dx.doi.org/10.1002/ajmg.a.61306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6935050PMC
October 2019

Cohesin complex-associated holoprosencephaly.

Brain 2019 09;142(9):2631-2643

Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.

Marked by incomplete division of the embryonic forebrain, holoprosencephaly is one of the most common human developmental disorders. Despite decades of phenotype-driven research, 80-90% of aneuploidy-negative holoprosencephaly individuals with a probable genetic aetiology do not have a genetic diagnosis. Here we report holoprosencephaly associated with variants in the two X-linked cohesin complex genes, STAG2 and SMC1A, with loss-of-function variants in 10 individuals and a missense variant in one. Additionally, we report four individuals with variants in the cohesin complex genes that are not X-linked, SMC3 and RAD21. Using whole mount in situ hybridization, we show that STAG2 and SMC1A are expressed in the prosencephalic neural folds during primary neurulation in the mouse, consistent with forebrain morphogenesis and holoprosencephaly pathogenesis. Finally, we found that shRNA knockdown of STAG2 and SMC1A causes aberrant expression of HPE-associated genes ZIC2, GLI2, SMAD3 and FGFR1 in human neural stem cells. These findings show the cohesin complex as an important regulator of median forebrain development and X-linked inheritance patterns in holoprosencephaly.
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http://dx.doi.org/10.1093/brain/awz210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7245359PMC
September 2019

Diagnostic Yield of an Algorithm for Neonatal and Infantile Cholestasis Integrating Next-Generation Sequencing.

J Pediatr 2019 08 31;211:54-62.e4. Epub 2019 May 31.

Pediatric Hepatology, Gastroenterology and Transplantation, Hospital Papa Giovanni XXIII, Bergamo, Italy.

Objective: To evaluate the performance of a diagnostic protocol for neonatal/infantile cholestasis in which the main clinical patterns steered the early use of different genetic testing strategies.

Study Design: An observational study was conducted between 2012 and 2017 in a tertiary care setting on a prospective cohort of children with cholestasis occurring at ≤1 year of age and persisting ≥6 weeks, to measure the detection rate of underlying monogenic diseases. After the exclusion of biliary atresia, a clinically driven genetic testing was performed, entailing 3 different approaches with different wideness: confirmatory single-gene testing; focused virtual panels; and wide search through trio whole-exome sequencing.

Results: We enrolled 125 children (66 female, median age 2 months); 96 (77%) patients had hypocholic stools and were evaluated rapidly to exclude biliary atresia, which was the final diagnosis in 74 (59%). Overall, 50 patients underwent genetic testing, 6 with single confirmatory gene testing, 38 through panels, and 6 with trio whole-exome sequencing because of complex phenotype. The genetic testing detection rate was 60%: the final diagnosis was Alagille syndrome in 11, progressive familial intrahepatic cholestasis type 2 in 6, alpha-1-antitrypsin deficiency in 3, and progressive familial intrahepatic cholestasis type 3 in 2; a further 7 genetic conditions were identified in 1 child each. Overall, only 18 of 125 (14%) remained with an indeterminate etiology.

Conclusions: This protocol combining clinical and genetic assessment proved to be an effective diagnostic tool for neonatal/infantile cholestasis, identifying inherited disorders with a high detection rate. It also could allow a noninvasive diagnosis in children presenting with colored stools.
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http://dx.doi.org/10.1016/j.jpeds.2019.04.016DOI Listing
August 2019