Funkčná charakterizácia zárodočných variantov u dedičnej trombocytopénie asociovanej so zvýšeným rizikom rozvoja hematologických malignít
| Title in English | Functional characterization of germline variants in hereditary thrombocytopenia associated with an increased risk of developing hematological malignancies |
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| Authors | |
| Year of publication | 2025 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
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| Description | Inherited thrombocytopenias (DT) are a heterogeneous group of rare disorders characterized by reduced platelet counts. Some forms of DT, such as those caused by pathogenic germline variants in the ANKRD26, ETV6, and RUNX1 genes, are associated with an increased risk of developing hematological malignancies (HM). In patients with these disorders, clinical manifestations are usually mild or absent, while the main risk lies in the development of malignancy. The diagnosis of DT is complicated by the absence of specific clinical symptoms and mild thrombocytopenia, which may remain undetected during routine examinations. An accurate diagnosis is often established only after HM occurs in multiple family members. Massive parallel sequencing has substantially improved the genetic diagnostics of these disorders, but has also introduced challenges related to the interpretation and classification of gene variants. In some cases, only a variant of uncertain significance (VUS) may segregate with the disease phenotype within a family. Proper interpretation of VUS is crucial for diagnosis and clinical management. One approach to determine the potential pathogenicity of identified VUS is functional analysis, the methodology of which varies depending on the gene's role. Pathogenic variants in the 5' untranslated region of the ANKRD26 gene cause inherited thrombocytopenia 2 (THC2), and approximately 8% of patients with THC2 develop a myeloid malignancy during their lifetime. The presence of pathogenic variants in the ANKRD26 gene leads to increased expression of this gene in megakaryocytes, thereby disrupting platelet production and causing thrombocytopenia. In our study, using functional analyses, including assessment of ANKRD26 expression in platelets by digital PCR and real-time PCR, we evaluated the significance of the ANKRD26 variants c.140C>G and c.-118C>T. Our results show that the presence of the c.-140C>G variant does not lead to increased ANKRD26 expression in platelets. Together with the clinical characterization of carriers of this variant and its high allele frequency (6.6% in the ACGT cohort of healthy individuals), these findings indicate that the c.140C>G variant is benign with respect to THC2. In contrast, functional analysis confirmed the pathogenicity of the c.-118C>T variant, which segregates with the THC2 phenotype across three generations of a single family. |
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