Dataset Information

Ena-DATASET-UCAM-GEL-25-06-2019-12:24:20:685-102 - samples

ABSTRACT: To identify novel causes of hereditary thrombocytopenia, we performed a genetic association analysis of whole-genome sequencing (WGS) data from 13,037 individuals enrolled in the NIHR BioResource, including 233 cases with isolated thrombocytopenia. We found an association between rare variants in the transcription factor (TF)-encoding gene IKZF5 and thrombocytopenia. We report five causal missense variants in or near IKZF5 zinc fingers (Znfs), of which two occurred de novo and three co-segregated in three pedigrees. A canonical DNA-Znf binding model predicts that three of the variants alter DNA recognition. Expression studies showed that chromatin binding was disrupted in mutant compared to wild-type (WT) IKZF5 and electron microscopy (EM) revealed a reduced quantity of alpha granules in normally sized platelets. Proplatelet formation (PPF) was reduced in megakaryocytes (MKs) from seven cases relative to six controls. Comparison of RNA-seq data from platelets, monocytes, neutrophils and CD4+ T-cells from three cases and 14 healthy controls showed 1,194 differentially expressed genes (DEGs) in platelets but only four DEGs in each of the other blood cell types. In conclusion, IKZF5 is a novel transcriptional regulator of megakaryopoiesis and the eighth transcription factor associated with dominant thrombocytopenia in humans.

PROVIDER: EGAD00001005107 | EGA |

REPOSITORIES: EGA

ACCESS DATA

Similar Datasets

Project description:Defects in blood development are a major contributor to complex congenital anomalies. Thrombocytopenia-Absent Radius (TAR) Syndrome is a rare congenital disease presenting with reduced blood platelets (megakaryocytic thrombocytopenia) and forelimb anomalies, concurrent with variable heart and kidney defects caused by hypomorphic RBM8A/Y14 gene function. RBM8A encodes a component of the ubiquitous exon junction complex involved in mRNA splicing, transport, and nonsense-mediated decay. How perturbing a general mRNA-processing factor causes the distinct phenotypes of TAR Syndrome remains unknown. Here, we connect zebrafish rbm8a perturbation to early hematopoiesis defects via attenuated planar cell polarity (PCP) signaling involved in controlling developmental cell arrangements. Combining different genetic means to reduce rbm8a function, we find a significant reduction of cd41-positive thrombocytes in hypomorphic rbm8a larvae. Transcriptomics analysis documents rbm8a-mutant zebrafish embryos already after gastrulation accumulate mRNAs with erroneously included introns, a hallmark of defective nonsense-mediated decay. Affected mRNAs include transcripts encoding components of the non-canonical Wnt pathway involved in PCP signaling, and rbm8a mutant-embryos show hallmarks of Wnt/PCP-dependent, early convergent extension defects. We establish that reduced rbm8a function synergizes with perturbations in Wnt/PCP pathway genes including wnt5b, wnt11f2, fzd7a, and vangl2. Following axis formation, rbm8a perturbation impairs the migration and architecture of the lateral plate mesoderm (LPM) that forms the hematopoietic, cardiovascular, kidney, and forelimb skeleton progenitors. Subsequently, rbm8a perturbation impairs expression of early hematopoietic/endothelial genes including runx1a, kdrl, sox7, and the megakaryocyte regulator gfi1aa. Lastly, we document similar hematopoietic defects upon loss of vangl2. Together, our data link reduced rbm8a function to LPM migration and hematopoietic defects via attenuated Wnt/PCP signaling. Our findings establish a developmental framework that connects the complex TAR Syndrome phenotypes to a potential LPM origin.

Dataset Information

Ena-DATASET-UCAM-GEL-25-06-2019-12:24:20:685-102 - samples

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure