Functional testing of gene variants in inherited thrombocytopenias

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F65269705%3A_____%2F20%3A00073250" target="_blank" >RIV/65269705:_____/20:00073250 - isvavai.cz</a>

Result on the web

<a href="https://www.phd.cz/archiv/Program_2020.pdf" target="_blank" >https://www.phd.cz/archiv/Program_2020.pdf</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Functional testing of gene variants in inherited thrombocytopenias

Original language description

Inherited thrombocytopenias (IT) are a heterogeneous group of familial haematopoietic disorders (FHD). To date more than 40 genes have been associated with IT. The determination of a correct diagnosis is essential for specialized care, therapy, and risk assessment for the offspring of affected IT patients. IT is routinely detected by blood-examinations. Commonly used methods (e.g. platelets morphology) do not have to determine the exact type of IT. Some IT patients can be misdiagnosed with immune thrombocytopenia. However spontaneous or lifethreatening bleeding usually does not occur. Some pathogenic variants for IT predispose patients to cancer, deafness, and other medical conditions. Using high-throughput genomic technologies of massive parallel sequencing (MPS), many variants in genes responsible for the IT phenotype have been identified (Savoia A, 2016). If a novel variant with uncertain significance (VUS) is detected, functional testing are necessary to determine its phenotypic effect. The interpretation of rare genetic VUSs, which are often characterized as unique and family-specific is very important in human molecular genetics (Jensen T.I. et al, 2019). The aim of our study was to investigate germline gene variants leading to the development of IT by modern genomic methods (whole exome sequencing, in silico prediction). It is of significant importance to determine the impact of VUSs on a patient&apos;s phenotype. Our research utilised in vitro models in mammalian/human cell lines together with microscopic and proteomic assays. We recently identified the novel VUS in GP1BA gene in a family with an inherited autosomal dominant (AD) macrotrombocytopenia, a monoallelic Bernard Soulier Syndrome (BSS). The big major significance of this finding is that BSS can be distinguished from idiopathic thrombocytopenic purpura. Using proteomic assays we have verified the known and novel interacting partners of wild-type and mutant variants of the GP1BA protein expressed in the mammalian cell line. Furthermore, we have revealed a novel VUS in the CYCS gene in an inherited AD thrombocytopenia segregating with affected family members. The detected variant was not found in the population databases. The structural effect of sequence variant of the CYCS gene p.(Thr20Ile) was analysed using in silico prediction to be possibly damaging. To date, only four families with CYCS-related thrombocytopenia have been described worldwide. Using microscopic assays we have verified the causality of the CYCS-variant on cell phenotype. We believe that the novel identification of VUSs of genes could set up more appropriate care and treatment of IT patients and predict complications associated with germline IT variants (e.g. malignancies). Functional testing of gene variants has helped to verify of their causality.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

30205 - Hematology

Project

<a href="/en/project/NV16-29447A" target="_blank" >NV16-29447A: Searching for mutations predisposing to familial hematologic and oncologic diseases</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů