scholarly journals Heritability and De Novo Mutations in Oesophageal Atresia and Tracheoesophageal Fistula Aetiology

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1595
Author(s):  
Erwin Brosens ◽  
Rutger W. W. Brouwer ◽  
Hannie Douben ◽  
Yolande van Bever ◽  
Alice S. Brooks ◽  
...  

Tracheoesophageal Fistula (TOF) is a congenital anomaly for which the cause is unknown in the majority of patients. OA/TOF is a variable feature in many (often mono-) genetic syndromes. Research using animal models targeting genes involved in candidate pathways often result in tracheoesophageal phenotypes. However, there is limited overlap in the genes implicated by animal models and those found in OA/TOF-related syndromic anomalies. Knowledge on affected pathways in animal models is accumulating, but our understanding on these pathways in patients lags behind. If an affected pathway is associated with both animals and patients, the mechanisms linking the genetic mutation, affected cell types or cellular defect, and the phenotype are often not well understood. The locus heterogeneity and the uncertainty of the exact heritability of OA/TOF results in a relative low diagnostic yield. OA/TOF is a sporadic finding with a low familial recurrence rate. As parents are usually unaffected, de novo dominant mutations seems to be a plausible explanation. The survival rates of patients born with OA/TOF have increased substantially and these patients start families; thus, the detection and a proper interpretation of these dominant inherited pathogenic variants are of great importance for these patients and for our understanding of OA/TOF aetiology.

2021 ◽  
pp. 0271678X2110267
Author(s):  
Peipei Pan ◽  
Shantel Weinsheimer ◽  
Daniel Cooke ◽  
Ethan Winkler ◽  
Adib Abla ◽  
...  

Brain arteriovenous malformations (bAVM) are an important cause of intracranial hemorrhage (ICH), especially in younger patients. The pathogenesis of bAVM are largely unknown. Current understanding of bAVM etiology is based on studying genetic syndromes, animal models, and surgically resected specimens from patients. The identification of activating somatic mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene and other mitogen-activated protein kinase ( MAPK) pathway genes has opened up new avenues for bAVM study, leading to a paradigm shift to search for somatic, de novo mutations in sporadic bAVMs instead of focusing on inherited genetic mutations. Through the development of new models and understanding of pathways involved in maintaining normal vascular structure and functions, promising therapeutic targets have been identified and safety and efficacy studies are underway in animal models and in patients. The goal of this paper is to provide a thorough review or current diagnostic and treatment tools, known genes and key pathways involved in bAVM pathogenesis to summarize current treatment options and potential therapeutic targets uncovered by recent discoveries.


2014 ◽  
Vol 57 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Robert Smigiel ◽  
Carlo Marcelis ◽  
Dariusz Patkowski ◽  
Nicole de Leeuw ◽  
Damian Bednarczyk ◽  
...  

2021 ◽  
Vol 134 (13) ◽  
Author(s):  
Priyanka Sandal ◽  
Chian Ju Jong ◽  
Ronald A. Merrill ◽  
Jianing Song ◽  
Stefan Strack

ABSTRACT Neurodevelopmental disorders (NDDs), including intellectual disability (ID), autism and schizophrenia, have high socioeconomic impact, yet poorly understood etiologies. A recent surge of large-scale genome or exome sequencing studies has identified a multitude of mostly de novo mutations in subunits of the protein phosphatase 2A (PP2A) holoenzyme that are strongly associated with NDDs. PP2A is responsible for at least 50% of total Ser/Thr dephosphorylation in most cell types and is predominantly found as trimeric holoenzymes composed of catalytic (C), scaffolding (A) and variable regulatory (B) subunits. PP2A can exist in nearly 100 different subunit combinations in mammalian cells, dictating distinct localizations, substrates and regulatory mechanisms. PP2A is well established as a regulator of cell division, growth, and differentiation, and the roles of PP2A in cancer and various neurodegenerative disorders, such as Alzheimer's disease, have been reviewed in detail. This Review summarizes and discusses recent reports on NDDs associated with mutations of PP2A subunits and PP2A-associated proteins. We also discuss the potential impact of these mutations on the structure and function of the PP2A holoenzymes and the etiology of NDDs.


2021 ◽  
Author(s):  
Evan Witt ◽  
Christopher B Langer ◽  
Li Zhao

Aging is a complex biological process which is accompanied by changes in gene expression and mutational load. In many species including humans, old fathers pass on more paternally-derived de novo mutations, however, the cellular basis and cell types driving this pattern are still unclear. To understand the root causes of this phenomenon, we performed single-cell RNA-sequencing (scRNA-seq) on testes from young and old male Drosophila, as well as genomic sequencing (DNA-seq) on somatic tissue from the same flies. We found that early germ cells from old and young flies have similar mutational loads, but older flies are less able to remove mutations during spermatogenesis. This indicates that germline mutations arise from primarily non-replicative factors, and that the increased mutational load of older males is due to differences in genome maintenance activities such as repairs to DNA damage. We also found that T>A mutations are enriched in older flies, and transcription-related enrichment terms are depleted in older males. Early spermatogenesis-enriched genes have lower dN/dS than late spermatogenesis-enriched genes, supporting the hypothesis that late spermatogenesis is the source of evolutionary innovation. This transcriptional disruption is reflected in the decreased expression of genome maintenance genes in early germ cells of older flies, as well as potentially aberrant transcription of transposable elements in the aging germline. Our results provide novel insights into the transcriptional and mutational signatures of the male germline.


Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.


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