BRCA1 status in Pakistani breast cancer patients with moderate family history

OBJECTIVE: To determine BRCA1 status in breast carcinoma patients of Pakistani origin. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: The Oncology Clinics of the Aga Khan University Hospital, Karachi, between May 2005 and December 2009. METHODOLOGY: Fifty three breast cancer patients based on clinical and laboratory diagnosis were recruited for this study. Moderate family history was defined as having a close relative (mother, daughter, sister) diagnosed with breast cancer under 45 years. Peripheral blood samples were collected from each patient in a 5 ml tube containing EDTA as anticoagulant. Subsequent to DNA extraction, mutational analysis of BRCA1 exons 2, 5, 6, 16, 20 and 22 was carried out using single strand conformation polymorphism (SSCP) assay while protein truncation test (PTT) was used to examine mutations in exon 11. All BRCA1 sequence variants were confirmed by DNA sequencing. RESULTS: Twenty-three patients were diagnosed with early onset breast cancer, 30 patients had moderate family history. At the time of diagnosis, the median age of enrolled patients was 39 years (range 24-65 years). Out of 53 patients, analyzed by SSCP assay, mobility shift was detected in exon 6, 16 and 20 of three patients, whereas one patient was tested positive for mutation in exon 11 by PTT assays. All patients with BRCA1 mutations were further confirmed by DNA sequencing analysis. In exon 16 c.4837A \u3e G was confirmed, which is a common polymorphism reported in several populations including Asians. Moreover, mutations in exon 6 (c.271T \u3e G), exon 20 (c.5231 delG) and exon 11 (c.1123 T \u3e G) were reported first time in the Pakistani population. CONCLUSION: Several BRCA1 mutations were observed in Pakistani breast cancer patients with moderate family history. Therefore, mutation-based genetic counselling for patients with moderate family history can facilitate management, if one first or second degree relative or early onset disease is apparent

Classic virilizing congenital adrenal hyperplasia presenting late: case series from Pakistan

Deficiency of 21 hydroxylase enzyme deficiency (21OH) activity accounts for 90% cases of congenital adrenal hyperplasia (CAH). This results in deficient cortisol, increased ACTH, adrenal hyperplasia and increased adrenal androgen secretion. There is marked virilization in genetic females which is the hallmark of this disorder. Genetic heterogeneity in 21 OHD is well recognized, and both severe and mild forms occur. We present three cases of adult females with the disease from a larger study to establish genotype, phenotype correlation of Pakistani patients with congenital adrenal hyperplasia (CAH) and to highlight issues such as diagnostic delay, inappropriate gender assignment at birth, and high degree of consanguinity among parents, psychosexual outcome of 21 OHD females and the need to develop expertise for early case detection. The analysis was done using Amplification Refractory Mutation System (ARMS) PCR. These cases show that CAH frequently remains undiagnosed during the newborn period in our population due to lack of awareness in the society and lack of proper diagnosis by the primary physician. There is a need to develop expertise for early case detection

Ethnic disparity in 21-hydroxylase gene mutations identified in Pakistani congenital adrenal hyperplasia patients

Background: Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders caused by defects in the steroid 21 hydroxylase gene (CYP21A2). We studied the spectrum of mutations in CYP21A2 gene in a multi-ethnic population in Pakistan to explore the genetics of CAH. Methods: A cross sectional study was conducted for the identification of mutations CYP21A2 and their phenotypic associations in CAH using ARMS-PCR assay. Results: Overall, 29 patients were analyzed for nine different mutations. The group consisted of two major forms of CAH including 17 salt wasters and 12 simple virilizers. There were 14 phenotypic males and 15 females representing all the major ethnic groups of Pakistan. Parental consanguinity was reported in 65% cases and was equally distributed in the major ethnic groups. Among 58 chromosomes analyzed, mutations were identified in 45 (78.6%) chromosomes. The most frequent mutation was I2 splice (27%) followed by Ile173Asn (26%), Arg 357 Trp (19%), Gln319stop, 16% and Leu308InsT (12%), whereas Val282Leu was not observed in this study. Homozygosity was seen in 44% and heterozygosity in 34% cases. I2 splice mutation was found to be associated with SW in the homozygous. The Ile173Asn mutation was identified in both SW and SV forms. Moreover, Arg357Trp manifested SW in compound heterozygous state. Conclusion: Our study showed that CAH exists in our population with ethnic difference in the prevalence of mutations examined

Medullary carcinoma of breast with a novel germline mutation 1123T \u3eG in exon 11 of BRCA1

Breast cancer, the most common malignancy in females, has an estimated 5-10% hereditary predisposition. BRCA1 is a tumor suppressor gene and is known to be responsible for breast cancer and breast-ovarian cancers running in families. In breast caner patients, several mutations in BRCA1 have been reported throughout the gene. This report describes identification of a mutation in BRCA1 gene using protein truncation (PTT) assay in a patient with medullary carcinoma of breast who also had a family history of breast cancer. Following DNA sequencing, the mutation was confirmed as substitution of thymine at position 1123 with guanine of exon 11 (1123 T\u3eG). This mutation can be added to the pool of known BRCA1 mutations in Pakistani population, which will help in developing a local screening panel of BRCA1 mutations

Prenatal screening for beta-thalassemia major reveals new and rare mutations in the Pakistani population

beta-Thalassemia is the most common genetic disorder in Pakistan, where more than 6000 affected children are born annually, and the carrier population is around 10 million. The objective was to study beta-globin gene mutations in chorionic villous biopsy samples. Prenatal screening of 383 pregnant women between 2003 and 2010 was carried out using a panel of 13 mutation primers and amplification refractory mutations system (ARMS)-PCR. In addition, DNA sequencing was used to confirm uncharacterized mutations and in some cases fetal disease status was confirmed by linkage analysis. Families enrolled in this study represented major ethnic groups in Pakistan. Of the 13 mutations tested, three mutations accounted 71% of the total, including IVS1-5(G-C)[HBB:c.92+5G \u3e C], codon 8/9(+G) [HBB:c.27_28insG] and del 619[NG_000007.3:g71609-72227del619]. Mutations in four uncharacterized samples were later confirmed by DNA sequencing as -88(C-T)[HBB:c.-138C \u3e G], -90(C-T)[HBB:c.-140C \u3e T] and codon 59(+T)[HBB:c.178_179insT]. To our knowledge, this is the first report of these mutations in Pakistan. Moreover, 19.2% fetal samples were normal and 52.3% heterozygous, whereas 26.4% were affected with thalassemia major. IVS1-5:IVS1-5 was the most common genotype in fetal samples. Prenatal diagnosis of beta-thalassemia using ARMS PCR is an efficient approach for reducing the burden of this disease in Pakistan. In addition, rare mutations reported in this study should be incorporated in the diagnostic strategy

Status of HER2 amplification, polysomy 17 and histopathological features of 425 Pakistani breast cancer patients.

HER2 gene amplification in invasive breast cancer is a robust predictive marker for response to transtuzumab therapy. This study was undertaken to measure concordance between immunohistochemistry (IHC) and FISH for HER2 gene amplification in invasive breast tumors, as well as the presence of polysomy 17 and possible correlation with demographics and histopathological variables, including ER and PR positivity. A total of 425 cases of infiltrating carcinoma of breast (99% IDC-NOS) were studied. HER2 over expression was tested by IHC and FISH methods. Association between IHC and FISH in both subsets was calculated by amplification ratio including polysomy 17. Out of 425 specimens, 128 (30%) were positive for HER2 amplification by FISH test, whereas only 78 (24%) tumors with 2+ expression showed amplification. In contrast, 39 (74%) demonstrated 3+ IHC score and HER2 gene amplification. The histological variables including tumor size, tumor type, and lymph node involvement did not influence the outcome of FISH analysis. The ER and PR status showed significantly greater positivity in Patients negative for HER2 amplification. Polysomy 17 was detected in 23.7% Patients and was positively associated with ER and PR expression (P