Biomedical subjects

Diptasri Mandal

Publications and source records attributed to Diptasri Mandal.

5 recordsLinked to original sources

PubMed2007

Identification of a novel tumor suppressor gene p34 on human chromosome 6q25.1.

In this study, we observed loss of heterozygosity (LOH) in human chromosomal fragment 6q25.1 in sporadic lung cancer patients. LOH was observed in 65% of the 26 lung tumors examined and was narrowed down to a 2.2-Mb region. Single-nucleotide polymorphism (SNP) analysis of genes located within this region identified a candidate gene, termed p34. This gene, also designated as ZC3H12D, C6orf95, FLJ46041, or dJ281H8.1, carries an A/G nonsynonymous SNP at codon 106, which alters the amino acid from lysine to arginine. Nearly 73% of heterozygous lung cancer tissues with LOH and the A/G SNP also exhibited loss of the A allele. In vitro clonogenic and in vivo nude mouse studies showed that overexpression of the A allele exerts tumor suppressor function compared with the G allele. p34 is located within a recently mapped human lung cancer susceptibility locus, and association of the p34 A/G SNP was tested among these families. No significant association between the less frequent G allele and lung cancer susceptibility was found. Our results suggest that p34 may be a novel tumor suppressor gene involved in sporadic lung cancer but it seems not to be the candidate familial lung cancer susceptibility gene linked to chromosomal region 6q23-25.

Alleles↗

PubMed2006

Acceptance of genetic testing for hereditary breast ovarian cancer among study enrollees from an African American kindred.

Clinical availability of genetic testing for cancer predisposition genes is generating a major challenge for U.S. health care systems to provide relevant genetic services to underserved populations. Here we present rates of study enrollment and utilization of genetic testing in a research study on BRCA1 testing acceptance in one large kindred. We also present data on baseline access to genetic information as well as enabling and obstructing factors to study enrollment. The study population included female and male members of an African American kindred based in the rural southern United States with an identified BRCA1 mutation. A combination of quantitative and qualitative data were collected and analyzed. Of the 161 living, eligible, and locatable kindred members, 105 (65%) enrolled in the study. Family, personal, and educational motivations were the most commonly endorsed reasons for study participation. The most commonly cited reasons for refusal to participate in the study were: lack of interest, time constraints, and negative experiences with prior participation in genetic research. Eighty three percent of the participants underwent BRCA1 testing. In multiple logistic regression analysis, age 40-49 (odds ratio (OR) = 6.9; 95% confidence interval (CI) = 1.2-39.5), increased perceived risk of being a BRCA1 mutation carrier (OR = 4.1; 95% CI = 1.1-14.6), and high cancer genetics knowledge levels (OR = 1.5; 95% CI = 1.1-2.3) were associated with BRCA1 testing acceptance. The results of this study indicate that cognitive and demographic factors may influence genetic research participation and genetic testing decisions among African Americans who are at increased risk of carrying a deleterious BRCA1 mutation.

Adult↗

PubMed2006

Risk reduction behaviors and provider communication following genetic counseling and BRCA1 mutation testing in an African American kindred.

Little is known about the impact of cancer genetic counseling and testing on health behaviors in racial and ethnic subgroups. This prospective observational study examined use of risk reduction strategies following BRCA1 counseling and testing. Participants were female members of an African American kindred who received genetic education, counseling and testing (n = 40) and completed a 1-year follow-up interview. Mutation carriers were more likely to opt for breast (100%, 7/7) and ovarian (25%; 1 of 4) cancer surveillance than prophylactic surgery. Following genetic counseling, 71% (5/7) of the BRCA1 carriers who opted for surveillance reported having a mammogram within the year following receipt of their genetic test results. Ovarian cancer screening among mutation carriers increased from 0% at baseline to 25% (one of four) at 1 year. Compared to noncarriers (23%, 7/30), carriers (70%, 7/10) were more likely to discuss their BRCA1 test results with their primary health care providers. Surveillance for breast cancer was preferred to prophylactic surgery and chemoprevention as a way to reduce risk for these cancers. Our data indicate that patient-provider communication about BRCA1 test results is suboptimal.

Adult↗

PubMed2005

The impact of receiving genetic test results on general and cancer-specific psychologic distress among members of an African-American kindred with a BRCA1 mutation.

BACKGROUND: Numerous studies have examined short-term and long-term psychologic responses to genetic testing for breast/ovarian carcinoma susceptibility in clinic samples and among families who participated in genetic linkage studies. However, to the authors' knowledge, the vast majority of studies focused on non-Latino whites and women. In this prospective study, the authors investigated the psychologic impact of receiving carrier-specific BRCA1 test results as part of a genetic education/counseling intervention in female and male members of an African-American kindred with a BRCA1 mutation. METHODS: Eighty-five of 101 participating kindred members (84%) underwent genetic counseling/education and testing according to an established protocol. Participants completed in-person or telephone-administered, computer-assisted interviews. At baseline and after the receipt of test results (1 mo, 4 mos, and 12 mos), general psychologic distress (i.e., anxiety and depression) and cancer-specific distress were measured. Statistical analyses were performed using linear mixed-model approaches for longitudinal data. RESULTS: The hypothesis that mutation carriers, particularly women who had no personal history of breast carcinoma, were expected to report greater distress than noncarriers was not supported. After controlling for socioeconomic status and personal history of breast/ovarian carcinoma, noncarriers reported significant declines in the distress measures (depressive symptoms, anxiety and cancer-related worries), whereas distress was not altered markedly in carriers after genetic risk notification. CONCLUSIONS: The current findings suggested that individuals receiving BRCA1 test results who learn that they are not carriers of a deleterious mutation may experience psychologic benefits. Furthermore, those who learned that they were mutation carriers did not appear to have adverse, clinically meaningful psychologic outcomes.

Adaptation, Psychological↗

PubMed2003

Importance sampling method of correction for multiple testing in affected sib-pair linkage analysis.

Using the Genetic Analysis Workshop 13 simulated data set, we compared the technique of importance sampling to several other methods designed to adjust p-values for multiple testing: the Bonferroni correction, the method proposed by Feingold et al., and naïve Monte Carlo simulation. We performed affected sib-pair linkage analysis for each of the 100 replicates for each of five binary traits and adjusted the derived p-values using each of the correction methods. The type I error rates for each correction method and the ability of each of the methods to detect loci known to influence trait values were compared. All of the methods considered were conservative with respect to type I error, especially the Bonferroni method. The ability of these methods to detect trait loci was also low. However, this may be partially due to a limitation inherent in our binary trait definitions.

Computer Simulation↗