Cardiac telomere attrition following changes in the expression of shelterin genes in pulmonary hypertensive chickens.

1. The alterations of relative telomere length and expression of shelterin genes (TRF1, TRF2, RAP1, POT1, and TPP1) were evaluated from the chickens' right heart ventricle in the early and last stages of cold-induced pulmonary hypertension (PHS) at 21 and 42 d of age.2. The relative telomere length in the right ventricular tissues was significantly shorter in the PHS group of broilers than in the control group at 42 d, but did not statistically change at 21 d of age. There was a significant negative correlation between relative telomere length and RV:TV ratio in the broilers at 42 d of age.3. The relative expression of POT1, RAP1 and TPP1 genes in the right ventricular tissues was significantly lower in the PHS group than in the control group at 21 d. The relative expression of the TRF2 gene was only higher in the PHS group of broilers than control at 42 d. The mRNA level of the TRF2 gene exhibited a significant positive correlation with RV:TV ratio at 42 d.4. It was concluded that most shelterin genes are dysregulated in the early stage of PHS (right ventricular hypertrophy) while telomere attrition occurs only at the last stage (heart dilation/failure).

A pan-Canadian prospective study of young women with breast cancer: the rationale and protocol design for the RUBY study.

Introduction: The understanding of the biology and epidemiology of, and the optimal therapeutic strategies for, breast cancer (bca) in younger women is limited. We present the rationale, design, and initial recruitment of Reducing the Burden of Breast Cancer in Young Women (ruby), a unique national prospective cohort study designed to examine the diagnosis, treatment, quality of life, and outcomes from the time of diagnosis for young women with bca. Methods: Over a 4-year period at 33 sites across Canada, the ruby study will use a local and virtual recruitment model to enrol 1200 women with bca who are 40 years of age or younger at the time of diagnosis, before initiation of any treatment. At a minimum, comprehensive patient, tumour, and treatment data will be collected to evaluate recurrence and survival. Patients may opt to complete patient-reported questionnaires, to provide blood and tumour samples, and to be contacted for future research, forming the core dataset from which 4 subprojects evaluating genetics, lifestyle factors, fertility, and local management or delivery of care will be performed. Summary: The ruby study will be the most comprehensive repository of data, biospecimens, and patient-reported outcomes ever collected with respect to young women with bca from the time of diagnosis, enabling research unique to that population now and into the future. This research model could be used for other oncology settings in Canada.

Improved diagnostic yield of neuromuscular disorders applying clinical exome sequencing in patients arising from a consanguineous population.

Neuromuscular diseases (NMDs) include a broad range of disorders affecting muscles, nerves and neuromuscular junctions. Their overlapping phenotypes and heterogeneous genetic nature have created challenges in diagnosis which calls for the implementation of massive parallel sequencing as a candidate strategy to increase the diagnostic yield. In this study, total of 45 patients, mostly offspring of consanguineous marriages were examined using whole exome sequencing. Data analysis was performed to identify the most probable pathogenic rare variants in known NMD genes which led to identification of causal variants for 33 out of 45 patients (73.3%) in the following known genes: CAPN3, Col6A1, Col6A3, DMD, DYSF, FHL1, GJB1, ISPD, LAMA2, LMNA, PLEC1, RYR1, SGCA, SGCB, SYNE1, TNNT1 and 22 novel pathogenic variants were detected. Today, the advantage of whole exome sequencing in clinical diagnostic strategies of heterogeneous disorders is clear. In this cohort, a diagnostic yield of 73.3% was achieved which is quite high compared to the overall reported diagnostic yield of 25% to 50%. This could be explained by the consanguineous background of these patients and is another strong advantage of offering clinical exome sequencing in diagnostic laboratories, especially in populations with high rate of consanguinity.

Prevalence of founder mutations in the BRCA1 and BRCA2 genes among unaffected women from the Bahamas.

Population-based testing for BRCA1/2 mutations detects a high proportion of carriers not identified by cancer family history-based testing. We sought to determine whether population-based testing is an effective approach to genetic testing in the Bahamas, where 23% of women with breast cancer carry one of seven founder mutations in the BRCA1 or BRCA2 gene. We determined the prevalence of founder BRCA mutations in 1847 Bahamian women without a personal history of breast or ovarian cancer, unselected for age or family history. We found that 2.8% (20/705) of unaffected women with a family history of breast/ovarian cancer and 0.09% (1/1089) of unaffected women without a family history carry a BRCA mutation. A total of 38% of unaffected women with a known mutation in the family were found to carry the familial mutation. We previously suggested that all Bahamian women with breast or ovarian cancer be offered genetic testing. These current data suggest that additionally all unaffected Bahamian women with a family history of breast/ovarian cancer should be offered genetic testing for the founder BRCA mutations.

Photo neutron dose equivalent rate in 15 MV X-ray beam from a Siemens Primus Linac.

Fast and thermal neutron fluence rates from a 15 MV X-ray beams of a Siemens Primus Linac were measured using bare and moderated BF3 proportional counter inside the treatment room at different locations. Fluence rate values were converted to dose equivalent rate (DER) utilizing conversion factors of American Association of Physicist in Medicine's (AAPM) report number 19. For thermal neutrons, maximum and minimum DERs were 3.46 × 10(-6) (3 m from isocenter in +Y direction, 0 × 0 field size) and 8.36 × 10(-8) Sv/min (in maze, 40 × 40 field size), respectively. For fast neutrons, maximum DERs using 9" and 3" moderators were 1.6 × 10(-5) and 1.74 × 10(-5) Sv/min (2 m from isocenter in +Y direction, 0 × 0 field size), respectively. By changing the field size, the variation in thermal neutron DER was more than the fast neutron DER and the changes in fast neutron DER were not significant in the bunker except inside the radiation field. This study showed that at all points and distances, by decreasing field size of the beam, thermal and fast neutron DER increases and the number of thermal neutrons is more than fast neutrons.

Factors associated with genetic counseling and BRCA testing in a population-based sample of young Black women with breast cancer.

Concerns about the potential for genomic advances to increase health disparities have been raised. Thus, it is important to assess referral and uptake of genetic counseling (GC) and testing in minority populations at high risk for hereditary breast and ovarian cancer (HBOC). Black women diagnosed with invasive breast cancer ≤age 50 in 2009-2012 were recruited through the Florida State Cancer Registry 6-18 months following diagnosis and completed a baseline questionnaire. Summary statistics, Chi-square tests, and path modeling were conducted to examine which demographic and clinical variables were associated with referral and access to genetic services. Of the 440 participants, all met national criteria for GC, yet only 224 (51 %) were referred for or received GC and/or HBOC testing. Variables most strongly associated with healthcare provider referral for GC included having a college education (OR 2.1), diagnosis at or below age 45 (OR 2.0), and triple negative tumor receptor status (OR 1.7). The strongest association with receipt of GC and/or HBOC testing was healthcare provider referral (OR 7.9), followed by private health insurance at diagnosis (OR 2.8), and household income greater than $35,000 in the year prior to diagnosis (OR 2.0). Study findings suggest efforts are needed to improve genetic services access among a population-based sample of high-risk Black women. These results indicate that socioeconomic factors and physician referral patterns contribute to disparities in access to genetic services within this underserved minority population.

Prevalence of PALB2 mutations in the Creighton University Breast Cancer Family Registry.

The purpose of this study is to determine the prevalence of PALB2 mutations among breast cancer families from the United States. The PALB2 gene was screened for mutations in 90 familial breast cancer patients from the Creighton University Breast Cancer Family Registry. These patients had previously tested negative for mutations in BRCA1 and BRCA2. Two of 90 breast cancer patients (2.2 %) were found to carry a truncating mutation in PALB2 (c.2411_2412delCT and c.2053delC). Both probands were diagnosed with breast cancer before age 35 and each had three relatives with breast cancer. Mutations in PALB2 are less common than BRCA1 and BRCA2 in familial breast cancer patients. However, testing for PALB2 mutations is a useful adjunct for patients undergoing testing for BRCA1 and BRCA2.

Strategies for recruitment of relatives of BRCA mutation carriers to a genetic testing program in the Bahamas.

The prevalence of BRCA1 and BRCA2 mutations among unselected breast cancer patients in the Bahamas is 23%. It is beneficial to advise relatives of mutation carriers that they are candidates for genetic testing. Women who test positive are then eligible for preventive interventions, such as oophorectomy. It is not clear how often relatives of women with a mutation in the Bahamas wish to undergo genetic testing for the family mutation. Furthermore, it is not clear how best to communicate this sensitive information to relatives in order to maximize patient compliance. We offered genetic testing to 202 first-degree relatives of 58 mutation carriers. Of 159 women who were contacted by the proband or other family member, only 14 made an appointment for genetic testing (9%). In contrast, among 32 relatives who were contacted directly by the genetic counselor, 27 came for an appointment (84%). This study suggests that for recruitment of relatives in the Bahamas, direct contact by counselor is preferable to using the proband as an intermediary.

Genetic testing for RAD51C mutations: in the clinic and community.

Much of the observed familial clustering of breast and ovarian cancer cannot be explained by mutations in BRCA1 and BRCA2. Several other cancer susceptibility genes have been identified, but their value in routine clinical genetic testing is still unclear. Germline mutations in RAD51C have been identified in about 1% of hereditary breast and ovarian cancer families. RAD51C mutations are predominantly found in families with a history of ovarian cancer and are rare in families with a history of breast cancer alone. RAD51C is primarily an ovarian cancer susceptibility gene. A mutation is present in approximately 1% of unselected ovarian cancers. Among mutation carriers, the lifetime risk of ovarian cancer is approximately 9%. The average age at onset is approximately 60 years; this suggests that preventive oophorectomy can be delayed until after natural menopause. Under current guidelines, genetic testing for RAD51C is expected to have a limited impact on ovarian cancer incidence at a population level. This is because the penetrance is 9% to age 80; the great majority of families with mutations would be represented by a single case of ovarian cancer, these are potentially preventable through population screening but not through screening of established ovarian cancer families.

Mutations predisposing to breast cancer in 12 candidate genes in breast cancer patients from Poland.

A number of genes other than BRCA1 and BRCA2 have been associated with breast cancer predisposition, and extended genetic testing panels have been proposed. It is of interest to establish the full spectrum of deleterious mutations in women with familial breast cancer.We performed whole-exome sequencing of 144 women with familial breast cancer and negative for 11 Polish founder mutations in BRCA1, CHEK2 and NBS1, and we evaluated the sequences of 12 known breast cancer susceptibility genes. A truncating mutation in a breast cancer gene was detected in 24 of 144 women (17%) with familial breast cancer. A BRCA2 mutation was detected in 12 cases, a (non-founder) BRCA1 mutation was detected in 5 cases, a PALB2 mutation was detected in 4 cases and an ATM mutation was detected in 2 cases. Polish women with familial breast cancer who are negative for founder mutations in BRCA1, CHEK2 and NBS1 should be fully screened for mutations in BRCA1, BRCA2 and PALB2. The PALB2 founder mutation c.509_519delGA should be included in the panel of Polish founder mutations.

Survival in women with ovarian cancer with and without microsatellite instability.

PURPOSE OF INVESTIGATION: Microsatellite instability (MSI) is a hallmark of defective mismatch repair and is present in approximately 20% of ovarian cancers. It is not known if the presence of MSI predicts survival in women with epithelial ovarian cancer. MATERIALS AND METHODS: Cases of epithelial ovarian cancer were ascertained from a population-based study in Ontario and tumour samples were tested for MSI, using five MSI markers. Patients were divided into MSI-high and MSI-low/normal, according to National Cancer Institute criteria. The authors compared the prevalence of specific prognostic factors in the two subgroups, including age, grade, stage, and histology. They estimated the hazard ratio for death from ovarian cancer associated with MSI-high and with other prognostic factors using a multi-variate analysis. RESULTS: A total of 418 ovarian cancer patients were included. One hundred and twenty-seven (19.7%) cancers were MSI- high. Subgroup analyses did not reveal any statistically significant differences for pathologic features associated with MSI status. No survival difference was seen according to MSI status. CONCLUSIONS: The presence of MSI in ovarian cancer is not associated with survival.

Recurrent mutations of BRCA1 and BRCA2 in Poland: an update.

Three founder alleles of BRCA1 (C61G, 4153delA, 5382insC) were reported in Poland in 2000, and these three mutations have comprised the standard testing panel used throughout the country. However, since 2000, other recurrent mutations of BRCA1 and BRCA2 have been reported. To establish if the inclusion of one or more of these mutations will increase the sensitivity of the standard test panel, we studied 1164 Polish women with unselected breast cancer diagnosed at age of 50 or below. All women were genotyped for 12 recurrent mutations of BRCA1 and BRCA2. We identified a mutation in 83 of 1164 patients (7.1%) including 61 women with one of the original three mutations (C61G, 4153delA, 5382insC) and 22 women with a different mutation (1.9%). Three new mutations (3819del5, 185delAG and 5370C>T) were seen in multiple families. By including these three mutations in the extended panel, the mutant frequency increased from 5.2 to 6.7%. Polish women with breast cancer diagnosed at age of 50 or below should be screened with a panel of six founder mutations of BRCA1 (C61G, 4153delA, 5382insC, 3819del5, 185delAG and 5370C>T).

The impact of a BRCA2 mutation on mortality from screen-detected prostate cancer.

BACKGROUND: Men with a BRCA2 mutation face an increased risk of prostate cancer. These cancers tend to have an aggressive nature and it has not yet been demonstrated that regular screening of BRCA2 carriers is associated with improved survival. METHODS: We identified 4187 men who underwent a prostate cancer biopsy for an elevated PSA or an abnormal digital rectal examination between 1998 and 2010. We screened the BRCA2 gene in its entirety for mutations and we followed the men for death from prostate cancer until December 2012. RESULTS: The 12-year prostate cancer-specific survival rate was 94.3% for men without a BRCA2 mutation and was 61.8% for men with a mutation (P<10(-4); log-rank test). CONCLUSIONS: The survival of men with screen-detected prostate cancer and a BRCA2 mutation is much poorer than expected.

The spectrum of BRCA1 and BRCA2 mutations in breast cancer patients in the Bahamas.

We sought to identify the full range of founder mutations in BRCA1 and BRCA2 in the Bahamas and to estimate the proportion of all BRCA1 and BRCA2 mutations that are accounted for by founder mutations. We studied 214 Bahamian women with invasive breast cancer, unselected for age or family history. A founder mutation had previously been identified in 49 patients. We conducted full sequencing of the BRCA1 and BRCA2 genes and multiplex ligation-dependent probe amplification (MLPA) for 156 patients. A novel founder mutation in BRCA2 (exon 17 818delA) was seen in four different patients and five other unique mutations in BRCA1 and BRCA2, including a large deletion (exons 8-9) in BRCA1. In total, a mutation was seen in 58 of the 214 patients (27%); 92% of carriers carried one of the seven founder mutations. Approximately 27% of unselected cases of breast cancer in the Bahamian population are attributable to a mutation in BRCA1 or BRCA2, a prevalence which far exceeds that of any other country. The majority of women who carry a mutation in the Bahamas, carry one of the seven founder mutations, making it possible to offer genetic testing to all women at risk for breast cancer in the Bahamas.

Frequency of mutations in mismatch repair genes in a population-based study of women with ovarian cancer.

BACKGROUND: Mutations in genes for hereditary non-polyposis colorectal cancer (HNPCC) in ovarian cancer patients remains poorly defined. We sought to estimate the frequency and characteristics of HNPCC gene mutations in a population-based sample of women with epithelial ovarian cancer. METHODS: The analysis included 1893 women with epithelial ovarian cancer ascertained from three population-based studies. Full-germline DNA sequencing of the coding regions was performed on three HNPCC genes, MLH1, MSH2 and MSH6. Collection of demographic, clinical and family history information was attempted in all women. RESULTS: Nine clearly pathogenic mutations were identified, including five in MSH6, two each in MLH1 and MSH2. In addition, 28 unique predicted pathogenic missense variants were identified in 55 patients. Pathogenic mutation carriers had an earlier mean age at diagnosis of ovarian cancer, overrepresentation of cancers with non-serous histologies and a higher number of relatives with HNPCC-related cancers. CONCLUSIONS: Our findings suggest that fewer than 1% of women with ovarian cancer harbour a germline mutation in the HNPCC genes, with overrepresentation of MSH6 mutations. This represents a lower-range estimate due to the large number of predicted pathogenic variants in which pathogenicity could not definitively be determined. Identification of mismatch repair gene mutations has the potential to impact screening and treatment decisions in these women.

Effects of supplementation of canola meal-based diets with arginine on performance, plasma nitric oxide, and carcass characteristics of broiler chickens grown at high altitude.

A total of 300 male broilers (Ross 308) were exposed to cool conditions at high altitudes to study the effects of dietary Arg supplementation on performance and physiological and zootechnical variables. A corn-soybean meal (SBM) and a corn-canola meal (CM) diet were formulated for the starting (1 to 3 wk of age) and growing (3 to 6 wk of age) stages according to NRC recommendations. Two additional diets were prepared by supplementing 0.2 and 0.4% l-Arg to the corn-CM diet. Substitution of CM for SBM caused a significant (P < 0.05) reduction in weight gain and feed intake and resulted in impaired feed:gain. Supplementing Arg in the CM diet restored the feed and weight losses to a significant extent so that a significant difference was found between CM diet and CM + 0.4% Arg in terms of weight gain for the growing (3 to 6 wk) stage and the entire study (1 to 6 wk; P < 0.05). Total plasma nitric oxide (NO) concentration analyzed by nitrate plus nitrite assay was measured in the treatment groups. A significant (P < 0.05) decrease in plasma NO level was observed by substituting CM for SBM in the diet. Supplementing the CM diet with Arg increased the plasma NO level above that of SBM group. Carcass and breast yields were significantly decreased (P < 0.05) as a result of substituting CM for SBM. The substitution of CM for SBM, however, significantly (P < 0.05) increased the proportions of thighs and heart. The right ventricular weight:total ventricular weight ratio and ascites mortality showed a significant (P < 0.05) increase when SBM was replaced by CM in the diet. Fortification of the CM diet with Arg eliminated the significant difference in the right-to-total ventricular weight ratios when compared with the SBM diet. In conclusion, feeding CM to broiler chickens raised at high altitude caused reduced growth performance and predisposed the birds to pulmonary hypertension and ascites, which were partly restored by Arg supplementation.

The effect of isotretinoin treatment on plasma homocysteine levels in acne vulgaris.

Isotretinoin has revolutionized the treatment of acne by improving the cosmetic outcome and decreasing the psychological damage. However, use of isotretinoin is associated with significant side-effects such as mucocutaneous involvement, dyslipidaemia and liver dysfunction, as indicated by increases in liver enzymes. The responsible enzyme for homocysteine metabolism, cystathionine-beta-synthase, might also be affected by isotretinoin-induced liver dysfunction, which leads to hyperhomocysteinaemia, an independent risk factor for thrombovascular diseases. The aim of this study was to evaluate homocysteine levels and the responsible vitamins for its metabolism in patients with moderate to severe acne vulgaris on isotretinoin treatment, before and after treatment. We found increased level of homocysteine in patients after 2 months of taking isotretinoin. Our findings suggest that isotretinoin may increase the risk of cardiovascular disorders by causing hyperhomocysteinaemia.

Germline BRCA2 mutations and the risk of esophageal squamous cell carcinoma.

The incidence of esophageal squamous cell carcinoma (ESCC) is very high among the Turkmen population of Iran. Family studies suggest a genetic component to the disease. Turkmen are ethnically homogenous and are well suited for genetic studies. A previous study from China suggested that BRCA2 might play a role in the etiology of ESCC. We screened for mutations in the coding region of the BRCA2 gene in the germline DNA of 197 Turkmen patients with ESCC. A nonsense variant, K3326X, was identified in 9 of 197 cases (4.6%) vs 2 of 254 controls (0.8%) (OR=6.0, 95% CI=1.3-28; P=0.01). This mutation leads to the loss of the C-terminal domain of the BRCA2 protein, a part of the region of interaction with the FANCD2 protein. We observed nine other BRCA2 variants in single cases only, including two deletions, and seven missense mutations. Six of these were judged to be pathogenic. In total, a suspicious deleterious BRCA2 variant was identified in 15 of 197 ESCC cases (7.6%).