Genotype-phenotype correlation and mutation spectrum of HBB gene in the Hatay province of Turkey

Year 2024, Volume: 49 Issue: 1, 40 - 46, 29.03.2024

Murat Kaçmaz , Semih Aşıkovalı

https://doi.org/10.17826/cumj.1394315

Abstract

Purpose: Thalassemia carriage and hemoglobinopathies are quite common disorders in Turkey, especially in the Çukurova region, including Hatay province. Due to the high case population and genetic diversity in our region, this study aimed to investigate the genotype-phenotype correlation in the HBB gene.
Materials and Methods: The data of patients who applied to Hatay Mustafa Kemal University Medical Genetics or Hematology Clinic between January 2010 and November 2022 were evaluated retrospectively.
Results: A total of 40 (100%) cases, comprising 25 (62.5%) homozygous and 15 (37.5%) compound heterozygous genotypes, were included in the study based on the mutation profiles in the HBB gene. In the analysis of the cases, it was seen that there were 17 different variants and 22 distinct genotypes. The three most common variants identified in this study were IVS-I-6 (T>C), IVS-I-1 (G>A), and IVS-II-848 (C>A). Of the cases with homozygous genotypes, 13 (52%) had the IVS-I-6 (T>C) variant. The most frequent genotypes observed in cases with compound heterozygous genotype were IVS-I-6 (T>C)/IVS-I-110 (G>A), IVS-I-6 (T>C)/Hb Knossos, and IVS-I-110 (G>A)/-101 C>T, each in 2 (13%) cases.
Conclusion: This study provides information on the phenotypic characteristics of very rare genotypes. We think that this information will be very beneficial, especially for clinicians interested in prenatal diagnosis, preimplantation genetic diagnosis, and postnatal genetic counseling.

Keywords

Hemoglobinopathies, hemoglobin Knossos, Genetic Counseling

Türkiye'nin Hatay ilinde HBB geninin genotip-fenotip korelasyonu ve mutasyon spektrumu

Abstract

Amaç: Talasemi taşıyıcılığı ve hemoglobinopatiler, aralarında Hatay ilininde bulunduğu Çukurova bölgesi başta olmak üzere Türkiye'de oldukça yaygın görülen rahatsızlıklardır. Bölgemizdeki vaka popülasyonunun ve genetik çeşitliliğin fazla olması nedeniyle bu çalışma HBB genindeki genotip-fenotip korelasyonunu araştırmayı amaçlamaktadır.
Gereç ve Yöntem: Hatay Mustafa Kemal Üniversitesi Tıbbi Genetik veya Hematoloji Kliniğine Ocak 2010 ve Kasım 2022 arasında başvuran hastaların verileri retrospektif olarak değerlendirildi.
Bulgular: Bu çalışmaya HBB genindeki mutasyon profillerine göre 25’i (%62,5) homozigot ve 15’i (%37,5) birleşik heterozigot genotipten oluşan toplam 40 (%100) olgu dahil edildi. Olguların analizinde 17 farklı varyant ve 22 farklı genotip olduğu görüldü. En sık saptanan üç varyant IVS-I-6 (T>C), IVS-I-1 (G>A) ve IVS-II-848 (C>A) idi. Homozigot genotipli olguların 13’ünde (%52) IVS-I-6 (T>C) varyantı vardı. Birleşik heterozigot genotipli olgularda en sık görülen genotipler, her biri 2 (%13) olguda görülmek üzere IVS-I-6 (T>C)/IVS-I-110 (G>A), IVS-I-6 (T>C)/Hb Knossos ve IVS-I-110 (G>A)/-101 C>T şeklindeydi.
Sonuç: Bu çalışmada oldukça nadir görülen genotiplerin fenotipik özelliklerine dair bilgiler mevcuttur. Bu bilgilerin özellikle doğum öncesi tanı, preimplantasyon genetik tanı ve doğum sonrası genetik danışmanlıkla ilgilenen klinisyenler için oldukça faydalı olacağı görüşündeyiz.

Keywords

Hemoglobinopatiler, hemoglobin Knossos, Genetik Danışmanlık

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