Project description:Familial pheochromocytoma (PCC) has been associated with germline mutations in 14 genes. Here we investigated three siblings, who presented with (metastatic) bilateral pheochromocytomas, renal oncocytoma, and erythrocytosis. By SNP-array on one patient’s germline DNA a large complex genomic alteration was identified encompassing the intragenic and promoter regions of Myc-Associated Factor X (MAX) and alpha-(1,6)-fucosyltransferase (FUT8). The alteration was confirmed in all patients, as well as loss of the wild type MAX and FUT8 alleles and corresponding loss of protein expression. Uniparental disomy of chromosome 14q, previously demonstrated as a hallmark for MAX-related PCC, was also shown in the index patient by SNP-array. Our results indicate that large genomic deletions of MAX should be considered in familial and bilateral PCC with prior negative testing for gene mutations. In addition, MAX appears to be a new tumor suppressor gene for renal oncocytomas. SNP array was performed for 2 samples: 1 tumor DNA sample and 1 corresponding germline DNA sample
Project description:Most cases of adult myeloid neoplasms are routinely assumed to be sporadic. Here, we describe an adult familial acute myeloid leukemia (AML) syndrome caused by germline mutations in the DEAD/H-Box helicase gene DDX41. DDX41 was also found to be affected by somatic mutations in sporadic cases of myeloid neoplasms as well as in a biallelic fashion in 50% of patients with germline DDX41 mutations. Moreover, corresponding deletions on 5q35.3 present in 6% of cases lead to haploinsufficient DDX41 expression. DDX41 lesions caused altered pre-mRNA splicing and RNA processing. DDX41 is exemplary of other RNA helicase genes also affected by somatic mutations, suggesting that they constitute a family of tumor suppressor genes.
Project description:Familial pheochromocytoma (PCC) has been associated with germline mutations in 14 genes. Here we investigated three siblings, who presented with (metastatic) bilateral pheochromocytomas, renal oncocytoma, and erythrocytosis. By SNP-array on one patient’s germline DNA a large complex genomic alteration was identified encompassing the intragenic and promoter regions of Myc-Associated Factor X (MAX) and alpha-(1,6)-fucosyltransferase (FUT8). The alteration was confirmed in all patients, as well as loss of the wild type MAX and FUT8 alleles and corresponding loss of protein expression. Uniparental disomy of chromosome 14q, previously demonstrated as a hallmark for MAX-related PCC, was also shown in the index patient by SNP-array. Our results indicate that large genomic deletions of MAX should be considered in familial and bilateral PCC with prior negative testing for gene mutations. In addition, MAX appears to be a new tumor suppressor gene for renal oncocytomas.
Project description:Most cases of adult myeloid neoplasms are routinely assumed to be sporadic. Here, we describe an adult familial acute myeloid leukemia (AML) syndrome caused by germline mutations in the DEAD/H-Box helicase gene DDX41. DDX41 was also found to be affected by somatic mutations in sporadic cases of myeloid neoplasms as well as in a biallelic fashion in 50% of patients with germline DDX41 mutations. Moreover, corresponding deletions on 5q35.3 present in 6% of cases lead to haploinsufficient DDX41 expression. DDX41 lesions caused altered pre-mRNA splicing and RNA processing. DDX41 is exemplary of other RNA helicase genes also affected by somatic mutations, suggesting that they constitute a family of tumor suppressor genes. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples.
Project description:Germline RUNX1 mutations are found in familial platelet disorders with predisposition to acute myelogenous leukemia (FPD/AML). This very rare disease is characterized by thrombocytopenia, platelet dysfunction and a 35% lifetime risk of developing MDS/AML and in rare cases also T-ALL. Here, we focus on a case of a man with a familial history of RUNX1 R174Q mutation who developed at the age of 42 years an EGIL T2-ALL and two years after remission an AML-M0. To investigate whether initial and relapsed leukemic blasts originated from the same clone, we performed CGH array and WES on both blasts populations. In both T2-ALL and AML-M0 samples, CGH array revealed loss of 1p36.32-23 and 17q11.2 and nine other small deletions. Both AML-M0 and T2-ALL demonstrated clonal rearrangements of both TCR (V9-J1-1) and TCR (D2-J1 and D2-J3). 18 genes were found by WES to be mutated in the original clone at a frequency of more than 40%. Additional variants were identified only in T2-ALL or in AML-M0 evoking the existence of a common original clone. MiSeq technology performed on peripheral blood-derived CD34+ cells five years prior T2-ALL development revealed only missense TET2 P1962T mutation at a frequency of 1% suggesting that this mutation in association with germline RUNX1 R174Q mutation led to amplification of a hematopoietic clone susceptible to acquire other transforming alterations. Identification of clonal hematopoiesis with acquired mutations at low frequency in hematopoietic progenitors before leukemia development could clearly serve as a marker of pre-leukemic state and might be helpful in patient care.
Project description:Mutation of the gene PARK2 is the most common cause of early-onset Parkinson's Disease (PD)1,2. PARK2 encodes a gene product with E3 ubiquitin ligase activity3. In a search for multisite tumor suppressors, we identified PARK2 as a frequently targeted gene on chromosome 6q25.2-q27 in cancer. Here, we describe inactivating somatic mutations and frequent intragenic deletions of PARK2 in human malignancies. The PARK2 mutations in cancer occur in the same domains, and sometimes, at the same residues as the germline mutations causing familial PD. Cancer-specific mutations abrogate the growth suppressive effects of PARK2. PARK2 mutations in cancer decrease the gene product's E3 ligase activity, compromising its ability to ubiquitinate cyclin E and resulting in mitotic instability. These data strongly point to PARK2 as a tumor suppressor on 6q25.2-q27. PARK2, a gene that causes neuronal dysfunction when mutated in the germline, may instead contribute to oncogenesis when altered in non-neuronal somatic cells.
Project description:Gastrointestinal stromal tumors (GIST) are thought to derive from the interstitial cells of Cajal (ICC) or an ICC precursor. Oncogenic mutations of the receptor tyrosine kinase KIT are present in most GIST. KIT K642E was originally identified in sporadic GIST and later found in the germ line of a familial GIST. A mouse model of harboring a germline Kit K641E mutant was created to model familial GIST. The expression profile was investigated in the gastric antrum in the knock-in Kit K641E murine GIST model by microarray.
Project description:Mutation of the gene PARK2 is the most common cause of early-onset Parkinson's Disease (PD)1,2. PARK2 encodes a gene product with E3 ubiquitin ligase activity3. In a search for multisite tumor suppressors, we identified PARK2 as a frequently targeted gene on chromosome 6q25.2-q27 in cancer. Here, we describe inactivating somatic mutations and frequent intragenic deletions of PARK2 in human malignancies. The PARK2 mutations in cancer occur in the same domains, and sometimes, at the same residues as the germline mutations causing familial PD. Cancer-specific mutations abrogate the growth suppressive effects of PARK2. PARK2 mutations in cancer decrease the gene product's E3 ligase activity, compromising its ability to ubiquitinate cyclin E and resulting in mitotic instability. These data strongly point to PARK2 as a tumor suppressor on 6q25.2-q27. PARK2, a gene that causes neuronal dysfunction when mutated in the germline, may instead contribute to oncogenesis when altered in non-neuronal somatic cells. Human colorectal samples were profiled on Agilent 244K aCGH arrays per manufacturer's instructions. Pooled reference normal DNA was used as the reference.
Project description:Patients with familial cerebral cavernous malformation (CCM) inherit germline loss of function mutations and are susceptible to progressive development of brain lesions and neurological sequelae during their lifetime. To date, no homologous circulat- ing molecules have been identified that can reflect the presence of germ line pathogenetic CCM mutations, either in animal models or patients. We hypothesize that homologous differentially expressed (DE) plasma miRNAs can reflect the CCM germline mutation in preclinical murine models and patients. Herein, homologous DE plasma miRNAs with mechanistic putative gene targets within the transcriptome of preclinical and human CCM lesions were identified. Several of these gene targets were additionally found to be associated with CCM-enriched pathways identified using the Kyoto Encyclopedia of Genes and Genomes. DE miRNAs were also identified in familial-CCM patients who developed new brain lesions within the year following blood sample collection. The miRNome results were then validated in an independent cohort of human subjects with real-time-qPCR quantification, a technique facilitating plasma assays. Finally, a Bayesian-informed machine learning approach showed that a combination of plasma levels of miRNAs and circulating proteins improves the associa- tion with familial-CCM disease in human subjects to 95% accuracy. These findings act as an important proof of concept for the future development of translatable circulating biomarkers to be tested in preclinical studies and human trials aimed at monitoring and restoring gene function in CCM and other diseases.
Project description:Patients with familial cerebral cavernous malformation (CCM) inherit germline loss of function mutations and are susceptible to progressive development of brain lesions and neurological sequelae during their lifetime. To date, no homologous circulat- ing molecules have been identified that can reflect the presence of germ line pathogenetic CCM mutations, either in animal models or patients. We hypothesize that homologous differentially expressed (DE) plasma miRNAs can reflect the CCM germline mutation in preclinical murine models and patients. Herein, homologous DE plasma miRNAs with mechanistic putative gene targets within the transcriptome of preclinical and human CCM lesions were identified. Several of these gene targets were additionally found to be associated with CCM-enriched pathways identified using the Kyoto Encyclopedia of Genes and Genomes. DE miRNAs were also identified in familial-CCM patients who developed new brain lesions within the year following blood sample collection. The miRNome results were then validated in an independent cohort of human subjects with real-time-qPCR quantification, a technique facilitating plasma assays. Finally, a Bayesian-informed machine learning approach showed that a combination of plasma levels of miRNAs and circulating proteins improves the associa- tion with familial-CCM disease in human subjects to 95% accuracy. These findings act as an important proof of concept for the future development of translatable circulating biomarkers to be tested in preclinical studies and human trials aimed at monitoring and restoring gene function in CCM and other diseases.