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Congenital Brain Malformations: An Integrated Diagnostic Approach. Semin Pediatr Neurol 2022; 42:100973. [PMID: 35868725 DOI: 10.1016/j.spen.2022.100973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 11/24/2022]
Abstract
Congenital brain malformations are abnormalities present at birth that can result from developmental disruptions at various embryonic or fetal stages. The clinical presentation is nonspecific and can include developmental delay, hypotonia, and/or epilepsy. An informed combination of imaging and genetic testing enables early and accurate diagnosis and management planning. In this article, we provide a streamlined approach to radiologic phenotyping and genetic evaluation of brain malformations. We will review the clinical workflow for brain imaging and genetic testing with up-to-date ontologies and literature references. The organization of this article introduces a streamlined approach for imaging-based etiologic classification into malformative, destructive, and migrational abnormalities. Specific radiologic ontologies are then discussed in detail, with correlation of key neuroimaging features to embryology and molecular pathogenesis.
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Aldinger KA, Dempsey JC, Tully HM, Grout ME, Mehaffey MG, Dobyns WB, Doherty D. Rhombencephalosynapsis: Fused cerebellum, confused geneticists. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2019; 178:432-439. [PMID: 30580482 DOI: 10.1002/ajmg.c.31666] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 10/27/2018] [Accepted: 10/29/2018] [Indexed: 11/07/2022]
Abstract
Rhombencephalosynapsis (RES) is a unique cerebellar malformation characterized by fusion of the cerebellar hemispheres with partial or complete absence of a recognizable cerebellar vermis. Subsets of patients also have other brain malformations such as midbrain fusion with aqueductal stenosis, characteristic craniofacial features (prominent forehead, flat midface, hypertelorism, ear abnormalities), and somatic malformations (heart, kidney, spine, and limb defects). Similar to known genetic brain malformations, the RES cerebellar malformation is highly stereotyped, yet no genetic causes have been identified. Here, we outline our current understanding of the genetic basis for RES, discuss limitations, and outline future approaches to identifying the causes of this fascinating brain malformation.
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Affiliation(s)
- Kimberly A Aldinger
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA
| | | | - Hannah M Tully
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA.,Department of Neurology, University of Washington, Seattle, Washington
| | - Megan E Grout
- Department of Pediatrics, University of Washington, Seattle, WA
| | | | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA.,Department of Pediatrics, University of Washington, Seattle, WA.,Department of Neurology, University of Washington, Seattle, Washington
| | - Dan Doherty
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA.,Department of Pediatrics, University of Washington, Seattle, WA
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Abdel-Hamid MS, El-Dessouky SH, Ateya MI, Gaafar HM, Abdel-Salam GMH. Phenotypic spectrum of NDE1-related disorders: from microlissencephaly to microhydranencephaly. Am J Med Genet A 2019; 179:494-497. [PMID: 30637988 DOI: 10.1002/ajmg.a.61035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 11/11/2018] [Accepted: 12/11/2018] [Indexed: 01/17/2023]
Abstract
Biallelic variants in the NDE1 gene have been shown to occur in extreme microcephaly. Most of the patients displayed microlissencephaly but one with microhydranencephaly. We report on three sibs in which the brain MRI and CT scans demonstrated variable degree of reduced volume of cerebral hemispheres and ventriculomegaly. Further, they had agenesis of corpus callosum, cerebellar, and brainstem hypoplasia. Fetal ultrasound at 32 weeks' gestation of the third sib revealed severe micrencephaly with extensive hydranencephaly and an anomaly consistent with non cleaved (fused) thalami. Because of the fused thalami, the STIL gene was targeted initially but showed negative results. His postnatal MRI showed that the cerebral hemispheres are markedly reduced in size (with no definite frontal, parietal, or occipital lobes) and replaced by a large sac filled with CSF. An intact falx cerebri was identified. This extensive hydarencephaly led us to consider the NDE1 and to identify a novel homozygous nonsense variant (c.54G>A, p.W18*). The variability of the degree of brain malformations and the apparent fusion of the thalami were illusive and delayed the recognition of the genetic etiology. Our results provide the first antenatal description of this rare syndrome. Further, we expand the genetic architecture and the neuroradiologic phenotype of NDE1-related disorders.
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Affiliation(s)
- Mohamed S Abdel-Hamid
- Medical Molecular Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Sara H El-Dessouky
- Prenatal Diagnosis and Fetal Medicine Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | | | | | - Ghada M H Abdel-Salam
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
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Vezain M, Lecuyer M, Rubio M, Dupé V, Ratié L, David V, Pasquier L, Odent S, Coutant S, Tournier I, Trestard L, Adle-Biassette H, Vivien D, Frébourg T, Gonzalez BJ, Laquerrière A, Saugier-Veber P. A de novo variant in ADGRL2 suggests a novel mechanism underlying the previously undescribed association of extreme microcephaly with severely reduced sulcation and rhombencephalosynapsis. Acta Neuropathol Commun 2018; 6:109. [PMID: 30340542 PMCID: PMC6195752 DOI: 10.1186/s40478-018-0610-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 09/29/2018] [Indexed: 12/13/2022] Open
Abstract
Extreme microcephaly and rhombencephalosynapsis represent unusual pathological conditions, each of which occurs in isolation or in association with various other cerebral and or extracerebral anomalies. Unlike microcephaly for which several disease-causing genes have been identified with different modes of inheritance, the molecular bases of rhombencephalosynapsis remain unknown and rhombencephalosynapsis presents mainly as a sporadic condition consistent with de novo dominant variations. We report for the first time the association of extreme microcephaly with almost no sulcation and rhombencephalosynapsis in a fœtus for which comparative patient-parent exome sequencing strategy revealed a heterozygous de novo missense variant in the ADGRL2 gene. ADGRL2 encodes latrophilin 2, an adhesion G-protein-coupled receptor whose exogenous ligand is α-latrotoxin. Adgrl2 immunohistochemistry and in situ hybridization revealed expression in the telencephalon, mesencephalon and rhombencephalon of mouse and chicken embryos. In human brain embryos and fœtuses, Adgrl2 immunoreactivity was observed in the hemispheric and cerebellar germinal zones, the cortical plate, basal ganglia, pons and cerebellar cortex. Microfluorimetry experiments evaluating intracellular calcium release in response to α-latrotoxin binding showed significantly reduced cytosolic calcium release in the fœtus amniocytes vs amniocytes from age-matched control fœtuses and in HeLa cells transfected with mutant ADGRL2 cDNA vs wild-type construct. Embryonic lethality was also observed in constitutive Adgrl2−/− mice. In Adgrl2+/− mice, MRI studies revealed microcephaly and vermis hypoplasia. Cell adhesion and wound healing assays demonstrated that the variation increased cell adhesion properties and reduced cell motility. Furthermore, HeLa cells overexpressing mutant ADGRL2 displayed a highly developed cytoplasmic F-actin network related to cytoskeletal dynamic modulation. ADGRL2 is the first gene identified as being responsible for extreme microcephaly with rhombencephalosynapsis. Increased cell adhesion, reduced cell motility and cytoskeletal dynamic alterations induced by the variant therefore represent a new mechanism responsible for microcephaly.
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Kotetishvili B, Makashvili M, Okujava M, Kotetishvili A, Kopadze T. Co-occurrence of Gomez-Lopez-Hernandez syndrome and Autism Spectrum Disorder: Case report with review of literature. Intractable Rare Dis Res 2018; 7:191-195. [PMID: 30181940 PMCID: PMC6119670 DOI: 10.5582/irdr.2018.01062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We report on Gomez-Lopez-Hernandez syndrome (GLHS) in a Caucasian patient, Georgian, 36 months, male, only child born to non-consanguineous parents. There were no similar cases in the family and among close relatives. MRI study confirmed rhombencephalosynapsis (fusion of cerebellar hemispheres in combination with the agenesis of cerebellar vermis) and mild dilation of the lateral ventricles. Other main findings are bilateral parieto-temporal alopecia and brachiturricephaly (broad skull shape and tower-like elongation of the cranium in the vertical axis), low-set posteriorly retracted ears, strabismus (in the right eye), hypotonia (Beighton scale score - 6) and ataxia (trouble maintaining balance). Patient has no signs of trigeminal anesthesia, no recurrent, painless eye infections, corneal opacities and ulcerated wounds on the facial skin and buccal mucosa were observed. Based on the scientific literature we suggest a finding of brachiturricephaly in addition to rhombencephalosynapsis and bilateral alopecia sufficient to put a diagnosis of GLHS. Patient did not speak, disregarded guardians and clinician addressing him, did not make eye contact, was restless and occasionally displayed aggression and self-injurious behavior. These symptoms confirm the earlier diagnosis of Autism Spectrum Disorder (ASD). Therefore, the current study describes a case of co-occurrence of GLHS and ASD.
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Affiliation(s)
| | - Malkhaz Makashvili
- Faculty of the Art and Sciences, Ilia State University, Tbilisi, Georgia
- Address correspondence to:Dr. Malkhaz Makashvili, Faculty of the Art and Sciences, Ilia State University, Cholokashvili st. 3/5, Tbilisi 0113, Georgia. E-mail:
| | - Michael Okujava
- Research Institute of Clinical Medicine, Tbilisi, Georgia
- Faculty of Natural Sciences and Engineering, Ilia State University, Tbilisi, Georgia
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Dubourg C, Kim A, Watrin E, de Tayrac M, Odent S, David V, Dupé V. Recent advances in understanding inheritance of holoprosencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:258-269. [PMID: 29785796 DOI: 10.1002/ajmg.c.31619] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/16/2022]
Abstract
Holoprosencephaly (HPE) is a complex genetic disorder of the developing forebrain characterized by high phenotypic and genetic heterogeneity. HPE was initially defined as an autosomal dominant disease, but recent research has shown that its mode of transmission is more complex. The past decade has witnessed rapid development of novel genetic technologies and significant progresses in clinical studies of HPE. In this review, we recapitulate genetic epidemiological studies of the largest European HPE cohort and summarize the novel genetic discoveries of HPE based on recently developed diagnostic methods. Our main purpose is to present different inheritance patterns that exist for HPE with a particular emphasis on oligogenic inheritance and its implications in genetic counseling.
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Affiliation(s)
- Christèle Dubourg
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Moléculaire et Génomique, CHU, Rennes, France
| | - Artem Kim
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France
| | - Erwan Watrin
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France
| | - Marie de Tayrac
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Moléculaire et Génomique, CHU, Rennes, France
| | - Sylvie Odent
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Clinique, CHU, Rennes, France
| | - Véronique David
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France.,Service de Génétique Moléculaire et Génomique, CHU, Rennes, France
| | - Valérie Dupé
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes) - UMR 6290, F - 35000, Rennes, France
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The New Findings in the Genetics and Pathology of Structural Brain Diseases. CURRENT PEDIATRICS REPORTS 2016. [DOI: 10.1007/s40124-016-0112-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Hryshchenko NV, Bychkova GM, Tavokina LV, Brovko AO, Graziano C, Soloviov OO, Hettinger JA, Patsalis PC, Lurie IW, Livshits LA. Unbalanced translocations involving chromosome region 10q25.3q26.3 in patients with intellectual disability and complex phenotypes. Cytogenet Genome Res 2015; 144:169-77. [PMID: 25573336 DOI: 10.1159/000370086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2014] [Indexed: 11/19/2022] Open
Abstract
We describe 2 Ukrainian families with unbalanced reciprocal translocations (RTs) involving the distal part of chromosome 10q. In both families, the fathers were healthy carriers of the RT. Two affected patients from the first family had an ∼2.3-Mb loss at 10q26.3 and an ∼25-Mb gain at 2q35qter, and the patient from the other family had an ∼12.5-Mb loss at 5p15.2pter and an ∼18-Mb gain at 10q25.3q26.3. We assume that intellectual disability (ID) in association with congenital anomalies observed in our patients was the result of the cumulative effect of both gains and losses of the chromosomal regions involved in each translocation. Comparison of the sizes of the deleted and duplicated segments in our families as well as in other published families with translocations affecting the distal part of 10q showed that generally deletions seem to be ∼2 times more harmful than duplications of the same size. The data obtained here may contribute to improve the diagnosis and genetic counseling of families with similar chromosomal imbalances.
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Affiliation(s)
- Nataliya V Hryshchenko
- Human Genomics Department, Institute of Molecular Biology and Genetics, NASU, Kiev, Ukraine
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