B. Vinod Kumar 1 Smita Lakhotia 2 Ravindran Ankathil 1 Jayaprakash Madhavan 3 P.G. Jayaprakash 3 M. Krishnan Nair 3 Kumaravel Somasundaram 2, * 1 Division of Cancer Research 2 Department of Microbiology and Cell Biology; Indian Institute of Science; Bangalore, India 560 012 3 Department of Radiation Oncology Regional Cancer Center; Trivandrum, India 695 011 *Correspondence to: Department of Microbiology and Cell Biology; Indian Institute of Science; Bangalore, India 560 012. Email: skumar@mcbl.iisc.ernet.in. Received 8/ 21/ 01; Accepted 8/ 22/ 01. Published online as a CB& T “ Papers In Press” at: www.landesbioscience.com/ journals/ cancer.html KEY WORDS BRCA1, Breast Cancer, CSGE, PCR, Mutation, Cancer Predisposition ABSTRACT Most of the predisposition to hereditary breast and ovarian cancer has been attributed to inherited defects in two tumor suppressor genes BRCA1 and BRCA2. To explore the contribution of BRCA1 mutations to hereditary breast cancer among Indian women, we examined the coding sequence of the BRCA1 gene in 14 breast cancer patients with a positive family history of breast and/ or ovarian cancer. Mutation analysis was carried out using conformation sensitive gel electrophoresis (CSGE) followed by sequencing. Three mutations (21%) in the BRCA1 gene were identified. Two of them are novel mutations of which one is a missense mutation in exon 7 near the RING finger domain, while the other is a one base pair deletion in exon 11 which results in protein truncation. The third mutation, 185delAG, has been previously described in Ashkenazi Jewish families. To our kno wledg e this is the first repo rt o f a study o f g ermline BRCA1 mutatio n analysis in familial breast cancer in India. O ur data from 14 different families suggests a lower prevalence but definite involvement of germline mutations in the BRCA1 gene among Indian women with breast cancer and a family history of breast cancer. SUM M ARY Breast cancer is one of the most common malignancies affecting women worldwide. Genetic predisposition for familial early onset of breast cancer accounts for approximately 5-10% of all breast cancers. Mutations in two autosomal dominant genes, BRCA1 and BRCA2 have been linked to familial breast cancer. This report provides the results of mutation analysis of BRCA1 gene in 14 breast cancer patients with a positive family history of breast and/or ovarian cancer from India. INTRODUCTION Breast cancer is one of the most common malignancies affecting women worldwide. In India, breast cancer is the second most common malignant condition among women. 1,2 Genetic predisposition for familial early onset of breast cancer accounts for approximately 5-10% of all breast cancers. Mutations in two autosomal dominant genes, BRCA1 and BRCA2 have been linked to familial breast cancer. 3-6 BRCA1 encodes an 1863 amino acid nuclear protein. Evidence implicates a role for BRCA1 in the control of gene expression, perhaps at the level of transcription. 7-12 A number of observations have linked BRCA1 to DNA damage response pathways. 13-17 The regulation and function of BRCA1 is probably very complex. Nevertheless, the finding that the mutations in BRCA1 are associated with hereditary breast cancer is a valuable information. Genetic testing could potentially offer different management options for the BRCA1 mutation carrying high-risk individuals. This report provides the results of mutation analysis of BRCA1 gene in 14 breast cancer patients with a positive family history of breast and/or ovarian cancer from India. We found that 21% of these families have mutations in BRCA1. M ATERIALS AND M ETHODS Patient Selection. All the patients included in this study were being treated at The Regional Cancer Centre, Trivandrum, India. Fourteen patients with breast or breast/ovarian cancer each from a different hereditary cancer family were chosen for the study. Each of these patients has at least one first-degree relative affected with breast or breast/ovarian cancer. Blood samples were collected from the patients and stored in acid-citrate-dextrose solution at -70˚C. Isolation of DNA from Blood Samples. Genomic DNA was isolated from 200 μl of blood sample using a commercial DNA isolation kit (Qiagen, USA). For PCR, the DNA was diluted to 25 ng/μl and 4 μl was used in a 25 μl PCR reaction. [Cancer Biology & Therapy 1, 18-21, January 2002]; published online as a CB&T “Papers In Press” at www.landesbioscience.com/journals/cancer.html Research Article Germline BRCA1 Mutation Analysis in Indian Breast/ Ovarian Cancer Families 18 Cancer Biology & Therapy 2002; Vol. 1 Issue 1