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Sarma A, Pruthi S. Congenital Brain Malformations- Update on Newer Classification and Genetic Basis. Semin Roentgenol 2023; 58:6-27. [PMID: 36732012 DOI: 10.1053/j.ro.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 12/31/2022]
Affiliation(s)
- Asha Sarma
- Department of Radiology, Vanderbilt University Medical Center, Monroe Carell Children's Hospital, Nashville, TN.
| | - Sumit Pruthi
- Department of Radiology, Vanderbilt University Medical Center, Monroe Carell Children's Hospital, Nashville, TN
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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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Henker LC, Lorenzett MP, Piva MM, Wronski JG, de Andrade DGA, Borges AS, Driemeier D, Oliveira-Filho JP, Pavarini SP. Alobar holoprosencephaly in an aborted American Quarter Horse fetus. J Equine Vet Sci 2022; 112:103898. [PMID: 35150851 DOI: 10.1016/j.jevs.2022.103898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 11/24/2022]
Abstract
Holoprosencephaly is a central nervous system malformation, characterized by incomplete or total lack of division of prosencephalon hemispheres, which is commonly accompanied by craniofacial malformations. A 9-month-gestation aborted American Quarter Horse fetus was submitted for postmortem examination. The fetus lacked haircoat and had severe facial malformations including marked shortening/absence of the maxillary, incisive and nasal bones, bilateral anophthalmia, and pre-maxillary agenesis. The prosencephalon was small and nearly spherical, represented by a single lobe, with no visible separation between cerebral hemispheres. The olfactory bulbs, piriform lobes, and the optic chiasm were absent. At cross-sectioning of the prosencephalon, the inner structures of the brain were completely absent, and replaced by a monoventricle lined by the remaining compressed cortex, and the thalami were fused. Since mutations in the sonic hedgehog (SHH) gene have been associated with human holoprosencephaly, the three coding SHH exons were sequenced using liver DNA of the aborted foal. The obtained SHH sequence was similar to the Equus caballus SHH mRNA sequence deposited in GenbankTM (XM_023640069.1); therefore, no polymorphism in the coding region of this gene justifying the phenotype was observed. This is the first report of alobar holoprosencephaly in horses.
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Affiliation(s)
- Luan Cleber Henker
- Setor de Patologia Veterinária, Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil.
| | - Marina Paula Lorenzett
- Setor de Patologia Veterinária, Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil
| | - Manoela Marchezan Piva
- Setor de Patologia Veterinária, Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil
| | - Júlia Gabriela Wronski
- Setor de Patologia Veterinária, Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil
| | - Danilo Giorgi Abranches de Andrade
- São Paulo State University (Unesp), School of Veterinary Medicine and Animal Science, Department of Veterinary Clinical Science,18618-681 Botucatu, Brazil
| | - Alexandre Secorun Borges
- São Paulo State University (Unesp), School of Veterinary Medicine and Animal Science, Department of Veterinary Clinical Science,18618-681 Botucatu, Brazil
| | - David Driemeier
- Setor de Patologia Veterinária, Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil
| | - José Paes Oliveira-Filho
- São Paulo State University (Unesp), School of Veterinary Medicine and Animal Science, Department of Veterinary Clinical Science,18618-681 Botucatu, Brazil
| | - Saulo Petinatti Pavarini
- Setor de Patologia Veterinária, Departamento de Patologia Clínica Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Bairro Agronomia, Porto Alegre, RS 91540-000, Brazil
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Abstract
Structural brain anomalies are relatively common and may be detected either prenatally or postnatally. Brain malformations can be characterized based on the developmental processes that have been perturbed, either by environmental, infectious, disruptive or genetic causes. Fetuses and neonates with brain malformations should be thoroughly surveilled for potential other anomalies, and depending on the nature of the brain malformation, may require additional investigations such as genetic testing, ophthalmological examinations, cardiorespiratory monitoring, and screening laboratory studies.
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Reis LM, Basel D, McCarrier J, Weinberg DV, Semina EV. Compound heterozygous splicing CDON variants result in isolated ocular coloboma. Clin Genet 2020; 98:486-492. [PMID: 32729136 PMCID: PMC8341436 DOI: 10.1111/cge.13824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/23/2020] [Accepted: 07/25/2020] [Indexed: 12/20/2022]
Abstract
Ocular coloboma is caused by failure of optic fissure closure during development and recognized as part of the microphthalmia, anophthalmia, and coloboma (MAC) spectrum. While many genes are known to cause colobomatous microphthalmia, relatively few have been reported in coloboma with normal eye size. Genetic analysis including trio exome sequencing and Sanger sequencing was undertaken in a family with two siblings affected with bilateral coloboma of the iris, retina, and choroid. Pathogenic variants in MAC genes were excluded. Trio analysis identified compound heterozygous donor splice site variants in CDON, a cell-surface receptor known to function in the Sonic Hedgehog pathway, c.928 + 1G > A and c.2650 + 1G > T, in both affected individuals. Heterozygous missense and truncating CDON variants are associated with dominant holoprosencephaly (HPE) with incomplete penetrance and Cdon-/- mice display variable HPE and coloboma. A homozygous nonsense allele of uncertain significance was recently identified in a consanguineous patient with coloboma and a second molecular diagnosis. We report the first compound heterozygous variants in CDON as a cause of isolated coloboma. CDON is the first HPE gene identified to cause recessive coloboma. Given the phenotypic overlap, further examination of HPE genes in coloboma is indicated.
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Affiliation(s)
- Linda M Reis
- Department of Pediatrics, Children’s Research Institute, Medical College of Wisconsin and Children’s Wisconsin, Milwaukee, WI 53226
| | - Donald Basel
- Department of Pediatrics, Children’s Research Institute, Medical College of Wisconsin and Children’s Wisconsin, Milwaukee, WI 53226
| | - Julie McCarrier
- Department of Pediatrics, Children’s Research Institute, Medical College of Wisconsin and Children’s Wisconsin, Milwaukee, WI 53226
| | - David V Weinberg
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Elena V Semina
- Department of Pediatrics, Children’s Research Institute, Medical College of Wisconsin and Children’s Wisconsin, Milwaukee, WI 53226
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
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