Spectrum and Prevalence of BRCA1/BRCA2 Variants in Aegean Region Hereditary Breast and Ovarian Cancer Cases

Year 2025, Volume: 12 Issue: 2, 120 - 126, 28.08.2025

Zehra Manav Yiğit , Gökay Bozkurt

https://doi.org/10.47572/muskutd.1623615

Abstract

In Western populations, 5–10% of breast cancer cases are hereditary, primarily due to pathogenic germline variants in BRCA1 and BRCA2 genes. Women carrying these variants have a lifetime risk of 40–57% for BC and 18–40% for ovarian cancer. This study aims to investigate the prevalence and distribution of BRCA1 and BRCA2 variants among hereditary breast and ovarian cancer cases in the Aegean region of Turkey. In this retrospective study, the medical records of 157 hereditary breast and ovarian cancer cases who presented to the Medical Genetics Clinic at Aydın Adnan Menderes University between 2013 and 2019 were reviewed. BRCA1 and BRCA2 gene analyses for these cases were performed using Sanger sequencing. The results were analyzed by collecting demographic and clinical data, including tumor characteristics and family history. Pathogenic or likely pathogenic variants were identified in 17 cases (11%) for BRCA1 and 6 cases (4%) for BRCA2. The most common BRCA1 variants were c.66dupA and c.5266dupC, while BRCA2 variants exhibited greater heterogeneity, with no recurrent variants. Breast cancer (72.6%) was the most frequent diagnoses, with invasive ductal carcinoma as the predominant histological subtype. The study underscores the importance of population-specific genetic testing strategies to identify BRCA1/2 variants. The findings reveal a unique variant spectrum in the Aegean Region population, highlighting the absence of globally common variants and the need for comprehensive genetic counseling to improve risk assessment and management for hereditary breast and ovarian cancer patients.

Keywords

BRCA1 , BRCA2 , Hereditary Breast and Ovarian Cancer , HBOC , Sanger Sequencing

Ege Bölgesi’nde Kalıtsal Meme ve Yumurtalık Kanseri Olgularında BRCA1/BRCA2 Varyantlarının Spektrumu ve Yaygınlığı

Abstract

Batı toplumlarında meme kanseri vakalarının %5-10'u kalıtsaldır ve başlıca BRCA1 ve BRCA2 genlerindeki patojenik germ hattı varyantlarından kaynaklanır. Bu varyantları taşıyan kadınların meme kanseri için yaşam boyu riski %40-57 ve over kanseri için %18-40'tır. Bu çalışma, Türkiye'nin Ege Bölgesi'ndeki kalıtsal meme ve over kanseri vakaları arasında BRCA1 ve BRCA2 varyantlarının sıklığını ve dağılımını araştırmayı amaçlamaktadır. Bu retrospektif çalışmada, Aydın Adnan Menderes Üniversitesi'nde 2013-2019 yılları arasında Tıbbi Genetik Polikliniği’ne başvuran ve Sanger dizilemesi ile BRCA1/2 genleri analiz edilen 157 kalıtsal meme ve over kanseri olgusunun dosyaları taranmıştır. Sonuçlar tümör özellikleri ve aile öyküsü de dahil olmak üzere demografik ve klinik veriler toplanarak analiz edilmiştir. BRCA1 için 17 vakada (%11) ve BRCA2 için 6 vakada (%4) patojenik veya muhtemel patojenik varyant saptanmıştır. En yaygın BRCA1 varyantları c.66dupA ve c.5266dupC iken, BRCA2 varyantları kümeleşme yapmadan daha fazla heterojenlik göstermiştir. Meme kanseri (%72,6) en sık tanı olarak belirlenmiş ve baskın histolojik alt tip olarak invaziv duktal karsinom görülmüştür. Çalışma, BRCA1/2 varyantlarını belirlemek için popülasyona özgü genetik test stratejilerinin önemini vurgulamaktadır. Bulgular, Ege Bölgesi popülasyonunda benzersiz bir varyant spektrumunu ortaya koyarak, küresel olarak yaygın varyantların çalışma ile uyumlu olmadığını göstermektedir. Ayrıca kalıtsal meme ve yumurtalık kanseri hastalarında risk değerlendirmesini ve hasta yönetimini iyileştirmek için kapsamlı genetik danışmanlığa olan ihtiyacı vurgulamaktadır.

Keywords

BRCA1 , BRCA2 , Ailesel Meme ve Yumurtalık Kanseri , Sanger Sekanslama

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