A B S T R A C T PurposeTwenty percent of individuals with a strong family and/or personal history of breast and ovarian cancer carry a deleterious mutation in BRCA1 or BRCA2. Identification of mutations in these genes is extremely beneficial for patients pursuing risk reduction strategies. Approximately 7% of individuals who have genetic testing of BRCA1 and BRCA2 carry a variant of uncertain significance (VUS), making clinical management less certain. The majority of identified VUS occur only in one to two individuals; these variants are not able to be classified using current classification models with segregation analysis components. MethodsTo develop a clinically applicable method that can predict the pathogenicity of VUS that does not require familial information or segregation analysis, we identified characteristics of breast or ovarian tumors that distinguished sporadic tumors from tumors with BRCA1 or BRCA2 mutations. Study participants included individuals with known deleterious mutations in BRCA1 or BRCA2 and individuals with classified or unclassified BRCA variants. ResultsWe applied the models to 57 tumors with 43 different deleterious BRCA mutations and 57 tumors with 54 unique classified and unclassified BRCA variants. Of the 33 previously unclassified VUS studied, we found evidence of neutrality for 21. ConclusionOur models showed 98% sensitivity and 76% specificity for predicting classified DNA changes. We classified 64% of unknown variants as neutral. Classification of VUS as neutral will have immediate benefit for those individuals and their family members. These models are adaptable for the clinic and will be useful for individuals with limited available family history.

Mutations in tumor suppressor genes BRCA1 and BRCA2 confer an increased lifetime risk of breast and ovarian cancer. Loss of heterozygosity (LOH) of the wildtype allele has been observed in approximately 80% of tumors from BRCA1 carriers and 70% of tumors from BRCA2 carriers and accounts for the majority of the "second-hits" occurring in BRCA-related tumors. Few sporadic tumors have been reported to have mutations in BRCA. Some sporadic tumors do show LOH of BRCA1 and BRCA2. BRCA1 promoter methylation has also been observed in sporadic ovarian and breast tumors; however, BRCA2 promoter methylation has not been reported in sporadic tumors. The relationship between BRCA LOH and BRCA promoter methylation has not been well characterized in tumors from BRCA germline mutation carriers. The goal of this study was to determine if BRCA1 and BRCA2 promoter hypermethylation serves as a "second-hit" in tumors from mutation carriers that do not show LOH. We studied 38 tumors from BRCA1 carriers and 23 tumors from BRCA2 carriers for LOH. To determine if BRCA1 and BRCA2 promoter hypermethylation serves as a "second-hit" in tumors with germline mutations, we tested 15 tumors lacking LOH and nine tumors with LOH for BRCA1 or BRCA2 promoter methylation. We identified seven BRCA1 tumors and nine BRCA2 tumors lacking LOH. Of these, only one tumor with a BRCA2 mutation showed promoter methylation. These data indicate that promoter methylation is a not a frequent "second-hit" in tumors from BRCA1 or BRCA2 carriers.

Supraventricular tachycardia (SVT) is the most common arrhythmia in the pediatric population. Despite its commonality, presentation of SVT can be nonspecific and varies based upon age with infants demonstrating fussiness or irritability and older children reporting vague perceptions of tachycardia or palpitations. Furthermore, SVT may manifest as self-limited paroxysms or with prolonged runs of SVT with subsequent development of cardiac dysfunction, heart failure, and multiorgan shock. Clinicians must maintain high levels of suspicion for SVT given the potentially dire consequences of untreated SVT. When diagnosed, there are effective acute and chronic treatments for SVT, with potential for spontaneous resolution in many infants.

BackgroundThe SNRK (sucrose‐nonfermenting–related kinase) enzyme is critical for cardiac function. However, the underlying cause for heart failure observed in Snrk cardiac conditional knockout mouse is unknown.Methods and ResultsPreviously, 6‐month adult mice knocked out for Snrk in cardiomyocytes (CMs) displayed left ventricular dysfunction. Here, 4‐month adult mice, on angiotensin II (Ang II) infusion, show rapid decline in cardiac systolic function, which leads to heart failure and death in 2 weeks. These mice showed increased expression of nuclear factor κ light chain enhancer of activated B cells (NF‐κB), inflammatory signaling proteins, proinflammatory proteins in the heart, and fibrosis. Interestingly, under Ang II infusion, mice knocked out for Snrk in endothelial cells did not show significant systolic or diastolic dysfunction. Although an NF‐κB inflammation signaling pathway was increased in Snrk knockout endothelial cells, this did not lead to fibrosis or mortality. In hearts of adult mice knocked out for Snrk in CMs, we also observed NF‐κB pathway activation in CMs, and an increased presence of Mac2+ macrophages was observed in basal and Ang II–infused states. In vitro analysis of Snrk knockdown HL‐1 CMs revealed similar upregulation of the NF‐κB signaling proteins and proinflammatory proteins that was exacerbated on Ang II treatment. The Ang II–induced NF‐κB pathway–mediated proinflammatory effects were mediated in part through protein kinase B or AKT, wherein AKT inhibition restored the proinflammatory signaling protein levels to baseline in Snrk knockdown HL‐1 CMs.ConclusionsDuring heart failure, SNRK acts as a cardiomyocyte‐specific repressor of cardiac inflammation and fibrosis.