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Prenatal Diagnosis Apr 2024Determine the incremental diagnostic yield of prenatal exome sequencing (pES) over chromosome microarray (CMA) or G-banding karyotype in fetuses with central nervous... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
Determine the incremental diagnostic yield of prenatal exome sequencing (pES) over chromosome microarray (CMA) or G-banding karyotype in fetuses with central nervous system (CNS) abnormalities.
METHODS
Data were collected via electronic searches from January 2010 to April 2022 in MEDLINE, Cochrane, Web of Science and EMBASE. The NHS England prenatal exome cohort was also included. Incremental yield was calculated as a pooled value using a random-effects model.
RESULTS
Thirty studies were included (n = 1583 cases). The incremental yield with pES for any CNS anomaly was 32% [95%CI 27%-36%; I = 72%]. Subgroup analysis revealed apparent incremental yields in; (a) isolated CNS anomalies; 27% [95%CI 19%-34%; I = 74%]; (b) single CNS anomaly; 16% [95% CI 10%-23%; I = 41%]; (c) more than one CNS anomaly; 31% [95% Cl 21%-40%; I = 56%]; and (d) the anatomical subtype with the most optimal yield was Type 1 malformation of cortical development, related to abnormal cell proliferation or apoptosis, incorporating microcephalies, megalencephalies and dysplasia; 40% (22%-57%; I = 68%). The commonest syndromes in isolated cases were Lissencephaly 3 and X-linked hydrocephalus.
CONCLUSIONS
Prenatal exome sequencing provides a high incremental diagnostic yield in fetuses with CNS abnormalities with optimal yields in cases with multiple CNS anomalies, particularly those affecting the midline, posterior fossa and cortex.
Topics: Pregnancy; Female; Humans; Prospective Studies; Hydrocephalus; Nervous System Malformations; Karyotyping; Karyotype; Fetus; Prenatal Diagnosis; Ultrasonography, Prenatal
PubMed: 38054560
DOI: 10.1002/pd.6466 -
Neuropathology and Applied Neurobiology Aug 2021Malformations of cortical development (MCD) include a heterogeneous spectrum of clinical, imaging, molecular and histopathological entities. While the understanding of...
AIMS
Malformations of cortical development (MCD) include a heterogeneous spectrum of clinical, imaging, molecular and histopathological entities. While the understanding of genetic causes of MCD has improved with the availability of next-generation sequencing modalities, genotype-histopathological correlations remain limited. This is the first systematic review of molecular and neuropathological findings in patients with MCD to provide a comprehensive overview of the literature.
METHODS
A systematic review was performed between November 2019 and February 2020. A MEDLINE search was conducted for 132 genes previously linked to MCD in order to identify studies reporting macroscopic and/or microscopic findings in patients with a confirmed genetic cause.
RESULTS
Eighty-one studies were included in this review reporting neuropathological features associated with pathogenic variants in 46 genes (46/132 genes, 34.8%). Four groups emerged, consisting of (1) 13 genes with well-defined histological-genotype correlations, (2) 27 genes for which neuropathological reports were limited, (3) 5 genes with conflicting neuropathological features, and (4) 87 genes for which no histological data were available. Lissencephaly and polymicrogyria were reported most frequently. Associated brain malformations were variably present, with abnormalities of the corpus callosum as most common associated feature.
CONCLUSIONS
Neuropathological data in patients with MCD with a defined genetic cause are available only for a small number of genes. As each genetic cause might lead to unique histopathological features of MCD, standardised thorough neuropathological assessment and reporting should be encouraged. Histological features can help improve the understanding of the pathogenesis of MCD and generate hypotheses with impact on further research directions.
Topics: Cerebral Cortex; Corpus Callosum; Humans; Lissencephaly; Malformations of Cortical Development; Nervous System Diseases; Neuropathology
PubMed: 33480109
DOI: 10.1111/nan.12696