Carriers Of Pathogenic Mutations Research Articles

Resistance to Insulin in Patients with Gitelman Syndrome and a Subtle Intermediate Phenotype in Heterozygous Carriers: A Cross-Sectional Study.

Gitelman syndrome is a salt-losing tubulopathy caused by mutations in the SLC12A3 gene, which encodes the thiazide-sensitive sodium-chloride cotransporter. Previous studies suggested an intermediate phenotype for heterozygous carriers. To evaluate the phenotype of heterozygous carriers of pathogenic SLC12A3 mutations, we performed a cross-sectional study of patients with Gitelman syndrome, heterozygous carriers, and healthy noncarriers. Participants measured their BP at home for three consecutive days before hospital admission for blood and urine sampling and an oral glucose tolerance test. We enrolled 242 participants, aged 18-75 years, including 81 heterozygous carriers, 82 healthy noncarriers, and 79 patients with Gitelman syndrome. The three groups had similar age, sex ratio, and body mass index. Compared with healthy noncarriers, heterozygous carriers showed significantly higher serum calcium concentration (P=0.01) and a trend for higher plasma aldosterone (P=0.06), but measures of home BP, plasma and urine electrolytes, renin, parathyroid hormone, vitamin D, and response to oral glucose tolerance testing were similar. Patients with Gitelman syndrome had lower systolic BP and higher heart rate than noncarriers and heterozygote carriers; they also had significantly higher fasting serum glucose concentration, higher levels of markers of insulin resistance, and a three-fold higher sensitivity to overweight. According to oral glucose tolerance testing, approximately 14% of patients with Gitelman syndrome were prediabetic, compared with 5% of heterozygous carriers and 4% of healthy noncarriers. Heterozygous carriers had a weak intermediate phenotype, between that of healthy noncarriers and patients with Gitelman syndrome. Moreover, the latter are at risk for development of type 2 diabetes, indicating the heightened importance of body weight control in these patients.

Morphological Changes in the Mitral Valve of Pathogenic Gene Mutation Carriers of Familial Hypertrophic Cardiomyopathy

Background: The shape of the mitral valve is remodeled as heart function changes, even before cardiac decompensation and obvious clinical symptoms appear. How does the early mitral valve morphology change in carriers of pathogenic gene mutation in hypertrophic cardiomyopathy(HCM)? Methods: Whole exome sequencing was performed on the probands of 258 families affected by HCM. Ninety-one families with definite pathogenic gene mutations. Sanger sequencing of families with definitive diseasecausing gene mutations was performed to verify the genotype, which was divided into the HCM group (G+/LVH+, n = 167); pathogenic gene mutationcarrying group (G+/LVH-, n = 149); and non-pathogenic gene mutationcarrying group (G-/LVH-, n = 189). Two-dimensional and three-dimensional ultrasound images were acquired from all family members, and mitral valve morphology parameters were analyzed and compared among the groups. Results: The results showed that the anteroposterior diameter and annulus height of G+/LVH+ were higher than those of G+/LVH- and G-/LVH-. The anterolateral-posteromedial diameter and sphericity index of G+/LVH+ and G+/LVH- differed significantly from those of G-/LVH-. The annulus circumference (3D), annulus area (2D), and annulus area (3D) of G+/LVH- were significantly lower than those of G+/LVH+ and G-/LVH-. The leaflets tenting volume, tenting height, commissural diameter, and annular height-to-commissural width ratio (AHCWR) (%) of G+/LVH- were significantly lower than those of G-/LVH- (1.4 ± 1.2 vs. 1.9 ± 0.9, p < 0.001) (7.7 ± 2.4 vs. 8.2 ± 2.0, p < 0.05), (2.8 ± 0.5 vs. 3.3 ± 0.3, p < 0.001), (23.1 ± 7.1 vs. 25.9 ± 6.5, p < 0.05). The angle between the mitral annulus plane and aortic valve annulus plane of G+/LVH+ was lower than that of G-/LVH- (134.4 ± 16.4 vs. 138.4 ± 13.4). Further studies revealed that mitral valve morphology parameters in the MYBPC3+/LVHgroup were significantly reduced compared with G-/LVH- group, whereas those parameters in the MYH7+/LVH- group showed no significant differences. Conclusions: Mitral valve morphological parameters show early deformation with a flatter appearance in pathogenic gene mutation carriers. They can be used as sensitive parameters to detect abnormal cardiac function in carriers of HCM, particularly in the carriers of MYBPC3 gene mutations. Funding Statement: This study was supported by grant no. 81671685 from the National Science Foundation of China and grant no. 17411954400 from the Science and Technology Committee Foundation of Shanghai. Declaration of Interests: The authors stated: None. Ethics Approval Statement: The study was approved by the Ethics Committee of Zhongshan Hospital, affiliated to Fudan University (no. 2016-16B), and all subjects gave informed consent.

PS1132 INHERITED DNA REPAIR AND CELL CYCLE GENE DEFECTS IN CHRONIC LYMPHOCYTIC LEUKEMIA

Background:Chronic lymphocytic leukemia (CLL) is among the most heritable cancers, with 60% of disease risk genetically determined. However, most of the genetic heritability of CLL remains unexplained. Previously, we identified ATM as the first CLL risk gene.Aims:Here we leverage a deep‐learning‐based germline variant calling algorithm to explore germline mutational enrichment in DNA repair and cell cycle genes in CLL.Methods:A two‐stage case‐control analysis was conducted using gene‐based mutational enrichment analysis of 50 established cancer predisposition DNA repair and cell cycle genes. In the discovery phase, a total of 285 Spanish patients and 5,608 ancestry‐matched controls were evaluated. In the validation stage, an independent cohort of 514 European patients and 27,173 ancestry‐matched controls were analyzed. An FDR correction was applied to both datasets and genes with a q‐value &lt;0.2 in both cohorts were considered significant.Results:Our joint analysis of 799 CLL patients from 2 genetically distinct cohorts and 32,781 ancestry‐matched cancer‐free controls identified ATM and CHEK2 as significantly enriched in both CLL datasets. First, our analysis recaptured the previously reported finding of ATM variant enrichment in CLL patients. Carriers of pathogenic ATM mutations in our cohorts (n = 9 patients, discovery: 1.05%, validation: 1.17%) were 2.8–3.7 times more likely to develop CLL compared to cancer‐free individuals (discovery: OR = 2.8, 95%CI = 0.7–9.0, q‐value = 0.181; validation: OR = 3.7, 95%CI = 1.6–8.3, q‐value = 0.0454). In addition, our analysis identified 21 CLL patients carrying pathogenic CHEK2 alterations (discovery: 1.40%, validation: 3.31%), making CLL patients 4.4–8.0 times more likely to carry such alterations compared to controls (discovery: OR = 8.0, 95%CI = 2.3–27.0, q‐value = 0.026; validation: OR = 4.4, 95%CI = 2.5–7.3, q‐value &lt;0.001).Summary/Conclusion:Our analysis of genetically distinct CLL cohorts, using a high‐sensitivity variant calling algorithm, supports CHEK2 as a potentially novel CLL predisposition gene that may explain a portion of the missing monogenic heritability of CLL. In addition, this study highlights the DNA repair and cell cycle regulation pathways as potential drivers of CLL susceptibility.

PS1133 GENOMIC ARRAYS IDENTIFY HIGH-RISK CHRONIC LYMPHOCYTIC LEUKEMIA WITH GENOMIC COMPLEXITY: A MULTI-CENTER STUDY

Background: Chronic lymphocytic leukemia (CLL) is among the most heritable cancers, with 60% of disease risk genetically determined. However, most of the genetic heritability of CLL remains unexplained. Previously, we identified ATM as the first CLL risk gene. Aims: Here we leverage a deep-learning-based germline variant calling algorithm to explore germline mutational enrichment in DNA repair and cell cycle genes in CLL. Methods: A two-stage case-control analysis was conducted using gene-based mutational enrichment analysis of 50 established cancer predisposition DNA repair and cell cycle genes. In the discovery phase, a total of 285 Spanish patients and 5,608 ancestry-matched controls were evaluated. In the validation stage, an independent cohort of 514 European patients and 27,173 ancestry-matched controls were analyzed. An FDR correction was applied to both datasets and genes with a q-value <0.2 in both cohorts were considered significant. Results: Our joint analysis of 799 CLL patients from 2 genetically distinct cohorts and 32,781 ancestry-matched cancer-free controls identified ATM and CHEK2 as significantly enriched in both CLL datasets. First, our analysis recaptured the previously reported finding of ATM variant enrichment in CLL patients. Carriers of pathogenic ATM mutations in our cohorts (n = 9 patients, discovery: 1.05%, validation: 1.17%) were 2.8–3.7 times more likely to develop CLL compared to cancer-free individuals (discovery: OR = 2.8, 95%CI = 0.7–9.0, q-value = 0.181; validation: OR = 3.7, 95%CI = 1.6–8.3, q-value = 0.0454). In addition, our analysis identified 21 CLL patients carrying pathogenic CHEK2 alterations (discovery: 1.40%, validation: 3.31%), making CLL patients 4.4–8.0 times more likely to carry such alterations compared to controls (discovery: OR = 8.0, 95%CI = 2.3–27.0, q-value = 0.026; validation: OR = 4.4, 95%CI = 2.5–7.3, q-value <0.001). Summary/Conclusion: Our analysis of genetically distinct CLL cohorts, using a high-sensitivity variant calling algorithm, supports CHEK2 as a potentially novel CLL predisposition gene that may explain a portion of the missing monogenic heritability of CLL. In addition, this study highlights the DNA repair and cell cycle regulation pathways as potential drivers of CLL susceptibility.

Inherited DNA repair and cell cycle gene defects in chronic lymphocytic leukemia.

1508 Background: Chronic lymphocytic leukemia (CLL) is among the most heritable cancers, with 60% of disease risk genetically determined. However, most of the genetic heritability of CLL remains unexplained. Previously, we identified ATM as the first CLL risk gene. Here, we leverage a deep-learning-based germline variant calling algorithm to explore germline mutational enrichment in DNA repair and cell cycle genes in CLL. Methods: A two-stage case-control analysis was conducted using gene-based mutational enrichment analysis of 50 established cancer predisposition DNA repair and cell cycle genes. In the discovery phase, a total of 285 Spanish patients and 5,608 ancestry-matched controls were evaluated. In the validation stage, an independent cohort of 514 European patients and 27,173 ancestry-matched controls were analyzed. An FDR correction was applied to both datasets and genes with a q-value &lt; 0.2 in both cohorts were considered significant. Results: Our joint analysis of 799 CLL patients from 2 genetically distinct cohorts and 32,781 ancestry-matched cancer-free controls identified ATM and CHEK2 as significantly enriched in both CLL datasets. First, our analysis recaptured the previously reported finding of ATM variant enrichment in CLL patients. Carriers of pathogenic ATM mutations in our cohorts (n = 9 patients, discovery: 1.05%, validation: 1.17%) were 2.8–3.7 times more likely to develop CLL compared to cancer-free individuals (discovery: OR = 2.8, 95%CI = 0.7–9.0, q-value = 0.181; validation: OR = 3.7, 95%CI = 1.6–8.3, q-value = 0.0454). In addition, our analysis identified 21 CLL patients carrying pathogenic CHEK2 alterations (discovery: 1.40%, validation: 3.31%), making CLL patients 4.4-8.0 times more likely to carry such alterations compared to controls (discovery: OR = 8.0, 95%CI = 2.3–27.0, q-value = 0.026; validation: OR = 4.4, 95%CI = 2.5–7.3, q-value &lt; 0.001). Conclusions: Our analysis of genetically distinct CLL cohorts, using a high-sensitivity variant calling algorithm, supports CHEK2 as a potentially novel CLL predisposition gene that may explain a portion of the missing monogenic heritability of CLL. In addition, this study highlights the DNA repair and cell cycle regulation pathways as potential drivers of CLL susceptibility.

Principles of Diagnosis and Personalized Treatment of Hereditary Colorectal Cancer

The most frequent forms of hereditary colorectal cancer syndromes are Lynch syndrome and familial adenomatous polyposis (FAP). All the patients with suspicion to these syndromes need precise clinical and genetic diagnostics. Affected patients need personalized program of treatment because standard algorithm cannot be considered sufficiently effective. Identification of a pathogenic mutation in a patient indicates the need for DNA diagnostics in his close relatives and only in this case all the carriers of pathogenic germline mutations can be included in the high-risk group. Algorithms of clinical monitoring and operative treatment for mutation carriers were developed in different countries. However, different populations have their own genetic and clinical features. The aim of this work was to highlight the principles of diagnosis and personalized treatment of patients with hereditary colorectal cancer, taking into account international and Russian recommendations.

Higher urate in LRRK2 mutation carriers resistant to Parkinson disease

LRRK2 mutations, the most common genetic cause of Parkinson disease (PD), display incomplete penetrance, indicating the importance of other genetic and environmental influences on disease pathogenesis in LRRK2 mutation carriers. The present study investigates whether urate, an antioxidant, Nrf2 activator, and inverse risk factor for idiopathic PD, is one such candidate biomarker of PD risk modulation in pathogenic LRRK2 mutation carriers. Banked plasma samples or urate levels were obtained for 3 cohorts of age- and sex-matched subjects with and without a known LRRK2 mutation in PD and unaffected controls to conduct a pilot study of 192 subjects from the LRRK2 Cohort Consortium (LCC) and 2 validation studies of 380 additional subjects from the LCC and 922 subjects from the Parkinson's Progression Markers Initiative. Urate levels were compared by multiple regression between subjects with and without a PD diagnosis conditional on LRRK2 status, controlling for age and sex. Nonmanifesting LRRK2 mutation carriers had significantly higher levels of urate than those who developed PD in each of the 3 independent cohorts. A meta-analysis demonstrated an adjusted mean difference of 0.62 mg/dL (p < 0.001), with similar results for separate assessments of women (p < 0.02) and men (p < 0.001). A 2 mg/dL increment in urate concentration decreased the odds of having PD by approximately 50% (odds ratio = 0.48, p = 0.004). These findings identify and substantiate urate as a biomarker of resistance to PD among LRRK2 mutation carriers. Ann Neurol 2019;85:593-599.

Prevalence and clinical outcomes of germline mutations in BRCA1/2 and PALB2 genes in 2769 unselected breast cancer patients in China.

To gain more information on the prevalence of germline mutations in BRCA1/2 and PALB2 genes in the Chinese population, and to explore the effects of the mutation status of these genes on clinical outcomes in patients with breast cancer, we performed a screening for BRCA1/2 and PALB2 mutations in a consecutive series of unselected breast cancer patients in the Chinese population. A total of 2,769 cases were enrolled between June 1993 and September 2017. All of the exons and exon-intron boundaries of the BRCA1/2 and PALB2 genes were screened with next-generation sequencing. Of the 2,769 breast cancer patients, BRCA1, BRCA2 and PALB2 mutations accounted for 2.7% (n = 74), 2.7% (n = 76), and 0.9% (n = 24), respectively. The BRCA1 gene had the highest mutation frequency in patients with triple-negative breast cancer (TNBC), which was 9.6% (n = 42), while the BRCA2 gene had the highest mutation frequency in patients with Luminal, which was 3.2% (n = 58). The disease-free survival (DFS) of BRCA1 mutation carriers was significantly lower than that of noncarriers (adjusted HR = 2.20, 95% CI = 1.15-4.18, p = 0.017). The mutation status of the PALB2 gene was significantly associated with the decline in overall survival (OS) (adjusted HR = 8.38, 95% CI = 2.19-32.11, p = 0.002). No significant difference was found between BRCA2 pathogenic mutation carriers and noncarriers. These results demonstrate that BRCA1 mutation status may be associated with a worse disease progression in patients with breast cancer, and women who harbored a PALB2 mutation might be at a higher risk of death due to breast cancer compared to noncarriers.

Genetic analysis of subsequent second primary malignant neoplasms in long-term pancreatic cancer survivors suggests new potential hereditary genetic alterations.

BackgroundThe principal aim of this report was to study second primary malignant neoplasms (SMNs) in long-term survivors of pancreatic ductal adenocarcinoma (PDAC) with regard to the germline genetic background.Patients and methodsA total of 118 PDAC patients after a curative-intent surgery who were treated between 2006 and 2011 were analyzed. Of the 22 patients surviving for >5 years, six went on to develop SMNs. A genetic analysis of 219 hereditary cancer-predisposition and candidate genes was performed by targeted next-generation sequencing in germline DNA from 20 of these patients.ResultsOf all the radically resected PDAC patients, six patients went on to subsequently develop SMNs, which accounted for 27% of the long-term survivors. The median time to diagnosis of SMNs, which included two cases of rectal cancer, and one case each of prostate cancer, malignant melanoma, breast cancer, and urinary bladder cancer, was 52.5 months. At the time of analysis, none of these patients had died as a result of PDAC progression. We identified four carriers of germline pathogenic mutations in 20 analyzed long-term survivors. One carrier of the CHEK2 mutation was found among four analyzed patients who developed SMNs. Of the remaining 16 long-term PDAC survivors, 3 patients (19%) carried germline mutation(s) in the MLH1+ ATM, CHEK2, and RAD51D gene, respectively.ConclusionThis retrospective analysis indicates that SMNs in PDAC survivors are an important clinical problem and may be more common than has been acknowledged to be the case. In patients with good performance status, surgical therapy should be considered, as the SMNs often have a favorable prognosis.

Germline mutations of renal cancer predisposition genes and clinical relevance in Chinese patients with sporadic, early-onset disease.

An inherited susceptibility to renal cancers is associated with multiple predisposing genes, but most screening tests are limited to patients with a family history. Next-generation sequencing (NGS)-based multigene panels provide an efficient and adaptable tool for investigating pathogenic germline mutations on a larger scale. This study investigated the frequency of pathogenic germline mutations in renal cancer predisposition genes in patients with sporadic, early-onset disease. An NGS-based panel of 23 known and potential renal cancer predisposition genes was used to analyze germline mutations in 190 unrelated Chinese patients under the age of 45 years who presented with renal tumors. The detected variants were filtered for pathogenicity, and then their frequencies were calculated and correlated with clinical features. Germline variants of the fumarate hydratase (FH) and BRCA1-associated protein 1 (BAP1) genes were comprehensively analyzed because of their aggressive potential. In total, 18 patients (9.5%) had germline mutations in 10 genes. Twelve of these 18 patients had alterations in renal cancer predisposition genes (6.3%), and 6 patients had mutations in potential predisposition genes such as BRCA1/2. Notably, pathogenic mutation carriers had a significant family history in second-degree relatives in comparison with those without pathogenic mutations (P<.001). Variants of unknown clinical significance in FH and BAP1 demonstrated evidence of additional somatic loss in tumors. In patients with early-onset disease, a multigene panel identified a high pathogenic germline mutation rate in renal cancer predisposition genes. This study emphasizes the importance of screening patients with early-onset disease for mutations in cancer predisposition genes. Germline screening should be encouraged in early-onset patients to provide personalized medicine and improve patient outcomes.

Clinical implementation of gene panel testing for lysosomal storage diseases.

BackgroundThe diagnostic workup in patients with a clinical suspicion of lysosomal storage diseases (LSD) is often difficult due to the variability in the clinical phenotype. The gold standard for diagnosis of LSDs consists of enzymatic testing. However, due to the sequential nature of this methodology and inconsistent genotype–phenotype correlations of certain LSDs, finding a diagnosis can be challenging.MethodWe developed and clinically implemented a gene panel covering 50 genes known to cause LSDs when mutated. Over a period of 18 months, we analyzed 150 patients who were referred for LSD testing and compared these results with the data of patients who were previously enrolled in a scheme of classical biochemical testing.ResultsOur panel was able to determine the molecular cause of the disease in 22 cases (15%), representing an increase in diagnostic yield compared to biochemical tests developed for 21 LSDs (4.6%). We were furthermore able to redirect the diagnosis of a mucolipidosis patient who was initially suspected to be affected with galactosialidosis. Several patients were identified as being affected with neuronal ceroid lipofuscinosis, which cannot readily be detected by enzyme testing. Finally, several carriers of pathogenic mutations in LSD genes related to the disease phenotype were identified as well, thus potentially increasing the diagnostic yield of the panel as heterozygous deletions cannot be detected.ConclusionWe show that the implementation of a gene panel for LSD diagnostics results in an increased yield in comparison to classical biochemical testing. As the panel is able to cover a wider range of diseases, we propose to implement this methodology as a first‐tier test in cases of an aspecific LSD presentation, while enzymatic testing remains the first choice in patients with a more distinctive clinical presentation. Positive panel results should however still be enzymatically confirmed whenever possible.

Heterozygous CTC1 Variants in Acquired Bone Marrow Failure

Germ line (GL) alterations of telomerase machinery genes may lead to inherited telomeropathies, but recent analysis of large control populations revealed that some of the previously assumed pathologic variants are present in comparable frequencies in healthy individuals. Pathogenic telomerase gene variants can be found, but are rare in idiopathic aplastic anemia (AA) and are associated with excessive telomere attrition. Previously, in a cohort of patients with MDS, pathogenic germ line variants of telomerase genes were very extremely rare.Recently a patient with bone marrow failure and liver cirrhosis presented with a biallelic CTC1 gene mutation. CTC1 is a member of the CTC complex, located on Chr 17p13.1, and critical for telomere replication. GL alterations of this gene were found to cause inherited disease, including Coats plus (CP), dyskeratosis congenital (DC) and cerebroretinal microangiopathy with calcifications and cysts (CRMCC) in a compound heterozygous manner. Our patient (age 28) had compound heterozygous CTC1 germline mutations (p.Lys242Leufs*41 and p.Cys985del) resulting in early childhood presentation of DC, subsequent severe AA at the age of 19, and a significant shortening of telomeres. Both parents as confirmed CTC1 variant carriers showed normal blood counts.Based on this index case and literature reports, manifest CTC1 diseases follow a recessive trait, however, but it is possible that heterozygous carriers may indeed have also an increased, albeit attenuated risk of BMF leading to a later manifestation or incomplete penetrance. To test this possible scenario we screened a cohort of acquired BMF (n=538) with AA/PNH (172), MDS/AML (n=366), with deep NGS of all coding regions of CTC1. In total, we identified 10 heterozygous CTC1 variants in 10 unrelated patients (8 AA/PNH and 2 MDS); 4/10 variants (1 stop gain R1202X and 3 frameshift deletions D405fs, P999fs, E454fs) were fulfilled the criteria of Tier-1 lesions and were found in AA/PNH patients (4/172, 2.3%), The remaining 6 missense variants were of uncertain significance or likely benign(Tier-2), 2 of which (H1092G and E1136K) were found in a compound heterozygous configuration in a AA/PNH patient. K438N, as a novel missense variant, was recurrently present in 2 MDS pts. Given the expected frequency of the CTC1 variants found in controls (104/33370, 0.3%), CTC1 variants appear to be enriched in AA/PNH subgroup (p<0.001). Of note is that none of the carriers of pathogenic CTC1 mutations showed any physical signs of inherited congenital BMF syndromes or any family history of leukemia, BMF and any other cancers. Interestingly, patients with sAA/PNH syndrome and biallelic CTC1 variant eventually evolved to MDS, while the other monoallelic CTC1 carriers showed stable disease and responsed to immunosuppression. Flow cytometric telomere length measurement (adjusted for age) showed a markedly shortened telomere in the index case, as well as 1 SAA case carrying biallelic CTC1 variants and 1 AA case with co-concurrent POT1 and CTC1 variants when compared with age matched controls. A significant difference was seen when comparing telomere length between CTC1 variants carriers and age-matched normal controls, while no difference was seen among CTC1 variants carriers, AA/PNH group without any variants.Because of the curious co-incidence of heterozygous CTC1 variants and AA/PNH, we further analyzed this subgroup for the presence of other telomerase gene mutations, 11/172 Tier-1 variants, while 6 Tier-1 GLVs detected in MDS. Most frequent SNVs were found in POT1 with 5/172 (3%) in AA/PNH and 3/366 (0.8%) in MDS/AML. Notably, in one AA/PNH patient POT1 stop gain variant (Q364X) was co-concurrent with CTC1 heterozygous frame shift deletion (P999fs). The enrichment of variants in TELO-related genes in AA/PNH subgroup was found in comparison to MDS/AML (p<.01) and ExAC database controls (p<.01). Further clinical phenotype analysis indicated that 3 AA/PNH cases harboring POT1, TINF2 and TERT Tier-1 variants had family history of cancer. Family history of cancer was also found in a MDS patient with a TINF2 variant.In sum, our results indicate that heterozygous CTC1 variants were associated with otherwise typical AA with clonal outgrowth of PNH clone and the presence of this variant does not seem to preclude response to immunosuppression. DisclosuresMaciejewski:Ra Pharmaceuticals, Inc: Consultancy; Ra Pharmaceuticals, Inc: Consultancy; Apellis Pharmaceuticals: Consultancy; Apellis Pharmaceuticals: Consultancy; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Alexion Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Cognitive Indicators of Preclinical Behavioral Variant Frontotemporal Dementia in MAPT Carriers.

The cognitive indicators of preclinical behavioral variant Frontotemporal Dementia (bvFTD) have not been identified. To investigate these indicators, we compared cross-sectional performance on a range of cognitive measures in 12 carriers of pathogenic MAPT mutations not meeting diagnostic criteria for bvFTD (i.e., preclinical) versus 32 demographically-matched familial non-carriers (n = 44). Studying preclinical carriers offers a rare glimpse into emergent disease, environmentally and genetically contextualized through comparison to familial controls. Evaluating personnel blinded to carrier status administered a standardized neuropsychological battery assessing attention, speed, executive function, language, memory, spatial ability, and social cognition. Results from mixed effect modeling were corrected for multiplicity of comparison by the false discovery rate method, and results were considered significant at p &lt; .05. To control for potential interfamilial variation arising from enrollment of six families, family was treated as a random effect, while carrier status, age, gender, and education were treated as fixed effects. Group differences were detected in 17 of 31 cognitive scores and spanned all domains except spatial ability. As hypothesized, carriers performed worse on specific measures of executive function, and social cognition, but also on measures of attention, speed, semantic processing, and memory storage and retrieval. Most notably, group differences arose on measures of memory storage, challenging long-standing ideas about the absence of amnestic features on neuropsychological testing in early bvFTD. Current findings provide important and clinically relevant information about specific measures that may be sensitive to early bvFTD, and advance understanding of neurocognitive changes that occur early in the disease. (JINS, 2019, 25, 184-194).

Treatment dilemmas in asymptomatic children with primary hemophagocytic lymphohistiocytosis

AbstractAsymptomatic carriers (ACs) of pathogenic biallelic mutations in causative genes for primary hemophagocytic lymphohistiocytosis (HLH) are at high risk of developing life-threatening HLH, which requires allogeneic hematopoietic stem cell transplantation (HSCT) to be cured. There are no guidelines on the management of these asymptomatic patients. We analyzed the outcomes of pairs of index cases (ICs) and subsequently diagnosed asymptomatic family members carrying the same genetic defect. We collected data from 22 HSCT centers worldwide. Sixty-four children were evaluable. ICs presented with HLH at a median age of 16 months. Seven of 32 ICs died during first-line therapy, and 2 are alive after chemotherapy only. In all, 23/32 underwent HSCT, and 16 of them are alive. At a median follow-up of 36 months from diagnosis, 18/32 ICs are alive. Median age of ACs at diagnosis was 5 months. Ten of 32 ACs activated HLH while being observed, and all underwent HSCT: 6/10 are alive and in complete remission (CR). 22/32 ACs remained asymptomatic, and 6/22 have received no treatment and are in CR at a median follow-up of 39 months. Sixteen of 22 underwent preemptive HSCT: 15/16 are alive and in CR. Eight-year probability of overall survival (pOS) in ACs who did not have activated HLH was significantly higher than that in ICs (95% vs 45%; P = .02), and pOS in ACs receiving HSCT before disease activation was significantly higher than in ACs receiving HSCT after HLH activation (93% vs 64%; P = .03). Preemptive HSCT in ACs proved to be safe and should be considered.

Access to Genetic Testing Impacts Oncologists´ Decisions on Ovarian Cancer Personalized Treatment: Lessons Learned From a National Program in Greece

Background: State health insurance authorities in Greece do not reimburse genetic testing for cancer predisposition. The Hellenic Society of Medical Oncology has launched and carries out a national program covering genetic testing for BRCA1/2 mutations detection, with the financial support of pharmaceutical industry. Aim: This analysis evaluates how, during this program, access to genetic testing transformed the oncologists' therapeutic approach toward their ovarian cancer patients and how the results impacted treatment decisions concerning PARP inhibitors. Adoption of testing by healthy relatives and timing of testing in the disease continuum were also evaluated. Methods: Adult patients with high-grade epithelial ovarian carcinoma, irrespectively of family history or age at diagnosis were eligible for this program. Genetic counseling was recommended before testing, and both were offered at no financial cost. First degree family members of pathogenic mutation carriers were also offered free counseling and testing. Results: From March 2015 through January 2018, 708 patients were enrolled and tested. One hundred and forty seven (20.7%) mutation carriers were identified, 102 (14.4%) in BRCA1 and 45 (6.3%) in BRCA2 gene. Testing was more often pursued at initial diagnosis (61%) than at recurrence (39%), as recorded for 409 patients with available relevant information. During the 1st year of the program, average monthly tests performed were 25.1, while during the 3rd year this number increased to 34.3 tests per month. Among patients who tested positive for deleterious BRCA1/2 mutations, relapse was reported in 58 patients, 94.8% of which (n= 55) received treatment with the PARP inhibitor olaparib as per its indication. Family members of 21 patients (14.3%), out of the 147 who tested positive, received genetic counseling and testing for the mutation identified in the context of the program. Conclusion: Free access to genetic testing for BRCA1/2 for ovarian cancer patients and genetic consultation facilitates testing uptake, affects common clinical practice &amp; has major impact on patients and their families. Still, diffusion of genetic information and broader testing of family members require further efforts by the oncological community.

The spectrum of BRCA1 gene mutations in early onset breast cancer patients from Russia

Aim of the study. Aim of the study was to estimate the occurrence of pathogenic mutations in the BRCA1 gene in Russian breast cancer patients.Material and methods. Complete coding sequence of the BRCA1 gene of 445 early onset breast cancer patients (under 40 years) from Novosibirsk region (Russia) were analyzed by targeted Next Generation Sequencing (NGS) using Ion Torrent platform. Results. Forty (9%) carriers of various pathogenic mutations were revealed. Thirty five (7,9%) patients carried 5382insC mutation, described earlier as a founder mutation for Slavic population. Five (1.1%) patients carried various pathogenic mutations, namely C61G, 462delCC, E143X, 4153delA, and IVS18+1G&gt;T. Besides, 29 genetic variants with no clinical significance or with unknown clinical significance were detected in BRCA1 gene among 445 early onset breast cancer patients. Conclusions. Data on the frequency of genetic variations in the BRCA1 gene among early onset breast cancer patients in the Novosibirsk Region (Russia) were obtained. Proportion of the 5382insC mutation is 87.5% of all pathogenic mutations in the BRCA1 gene found in patients.

Risk-adapted approach to prostate cancer screening

Mass prostatic specific antigen (PSA) testing (population-based PSA screening) has remained controversial, nevertheless there are men cohorts likely to benefit from PSA screening. Heritable factors contribute to 60 % risk for developing familial prostate cancer. Despite the fact that its clinical application is challenging due to polygenic inheritance, advances in new generation sequencing technologies permit identifying highly penetrant germline mutations in genes BRCA1, BRCA2, CHEK2, HOXB13 and MMR associated with tremendous increase in risk of developing the prostate cancer. Several germline mutations are associated with clinically aggressiveness of disease and shortened survival. Targeted screening that is based on family history and genomic aberrations should be the next step towards the precision medicine. Men at elevated risk should been performed for early detection are those with familiar history of prostate cancer, or BRCA1, BRCA2, CHEK2, HOXB13 and MMR pathogenic germline mutation carriers, or first line relatives diagnosed with certain types of cancer. Systematic PSA testing in 1–2 years among germline mutation carriers men beginning at age 45 years would contribute to increase in early detection of localized prostate cancer resulting in more chance of curative treatment and improve survival rates

Adrenocortical carcinoma (ACC): When and why should we consider germline testing?

Adrenocortical carcinoma (ACC), particularly when occurring during childhood, has been a traditional component of the tumor spectrum of Li-Fraumeni syndrome. Recent research has defined a significant risk increase of ACC with other familial cancer syndromes, such as Lynch syndrome and multiple endocrine neoplasia. ACC patients can serve as index patients for a new family diagnosis of a hereditary syndrome, allowing for further family cascade genetic testing, impacting the care and surveillance for patients and at risk family members. Individuals carrying pathogenic genetic variants can embark on a regular preventive screening and surveillance protocol likely reducing morbidity and mortality. Although several of these hereditary predisposition syndromes lead to a very high relative risk increase for ACC, the absolute risk most often does not reach a level to recommend general screening for ACC in carriers of pathogenic mutations. The larger value lies in the ability to screen for other commonly associated tumors in pathogenic variant carriers, such as colon cancer with Lynch syndrome. Here, we review the risk for ACC associated with hereditary syndromes and suggest an approach for genetic evaluation for ACC patients.

PO-016 The role of autophagy-related protein 9B in liver carcinogenesis

IntroductionAccording to the National Cancer Register in Bulgaria more than 800 women develop ovarian cancer annually. The most frequent histological type, representing about three quarters of these cases is high-grade serous ovarian carcinoma (HS-OC). About 25% of the HG-OC are supposed to be caused by mutations in the BRCA1 and BRCA2 genes.Material and methodsWe have screened 80 Bulgarian patients with high grade serous ovarian cancer (HS-OC), disease progression and platinum sensitivity for germline mutations in the BRCA1/2 genes. The mutation analysis was performed by Next Generation Sequencing (NGS) with Ion Torrent PGM System, Sanger Sequencing and MLPA (Multiplex Ligation Dependent Probe Amplification). All identified pathogenic variants with NGS were confirmed by direct sequencing.Results and discussionsIn total 26 (32.5%) pathogenic mutations were found of which 23 (28.75%) in BRCA1: three recurrent c.5263_5264insC (7/80), c.2019delA (3/80), c.5333–1G>A (2/80), the rest appearing just once c.139T>C, c.139T>G, c.181T>G, c.3496delG, c.4391delC, c.5212G>A, c.5497G>A, c.5533_5534insT, deletion of exons 3–7. In BRCA2 only 4 (5%) mutations were found: c.3545_3546delTT, c.8059_8063delGTTCT, c.8674A>T, c.9294C>G. The most prevalent mutation in the study group observed with frequency of 8.75% was c.5263_5264insC, followed by c.2019delA (3.75%) and c.5333–1G>T (2.50%) in BRCA1. The recurrent mutations account for 57.7% of all detected mutations.ConclusionTwenty six (32.5%) of the HS-OC patients in our study were carriers of germline pathogenic mutations. These results are relevant to the clinical practice and personalised treatment of patients with OC. The BRCA1 and BRCA2 mutations are related to survival and chemotherapy response. The mutation carriers, detected by NGS sequencing, could benefit from therapy with PARP inhibitor.AcknowledgementsDUNK01-2/2009/NSF, Ministry of Education and Science, Bulgaria, AstraZeneca LTD, Bulgaria

Genetic variants associated with Alzheimer\u2019s disease confer different cerebral cortex cell-type population structure

BackgroundAlzheimer’s disease (AD) is characterized by neuronal loss and astrocytosis in the cerebral cortex. However, the specific effects that pathological mutations and coding variants associated with AD have on the cellular composition of the brain are often ignored.MethodsWe developed and optimized a cell-type-specific expression reference panel and employed digital deconvolution methods to determine brain cellular distribution in three independent transcriptomic studies.ResultsWe found that neuronal and astrocyte relative proportions differ between healthy and diseased brains and also among AD cases that carry specific genetic risk variants. Brain carriers of pathogenic mutations in APP, PSEN1, or PSEN2 presented lower neuron and higher astrocyte relative proportions compared to sporadic AD. Similarly, the APOE ε4 allele also showed decreased neuronal and increased astrocyte relative proportions compared to AD non-carriers. In contrast, carriers of variants in TREM2 risk showed a lower degree of neuronal loss compared to matched AD cases in multiple independent studies.ConclusionsThese findings suggest that genetic risk factors associated with AD etiology have a specific imprinting in the cellular composition of AD brains. Our digital deconvolution reference panel provides an enhanced understanding of the fundamental molecular mechanisms underlying neurodegeneration, enabling the analysis of large bulk RNA-sequencing studies for cell composition and suggests that correcting for the cellular structure when performing transcriptomic analysis will lead to novel insights of AD.