HBQ1 (hemoglobin subunit theta 1) is a globin gene located in the alpha-globin gene cluster on chromosome 16.3, functioning as part of the hemoglobin complex with roles in oxygen transport and erythrocyte development 1. The gene exhibits protein binding and heme binding activities, contributing to oxygen carrier function within the haptoglobin-hemoglobin complex 1. HBQ1 is frequently involved in alpha-thalassemia disorders through large deletions that remove multiple genes in the alpha-globin cluster, including HBA1, HBA2, and HBQ1, resulting in alpha0-thalassemia phenotypes 23. A damaging missense variant (p.G52A) in HBQ1 has been associated with decreased mean corpuscular hemoglobin levels, indicating its functional importance in red blood cell hemoglobin content 4. Beyond hematological functions, HBQ1 has emerged as a potential biomarker in other conditions, showing diagnostic value for coronary in-stent restenosis 5 and being identified as part of a genetic signature predicting glucose metabolic profiles in gastric cancer 6. The gene's involvement in large deletions can have implications for genetic counseling, as homozygosity may lead to severe conditions like Hb Bart's hydrops fetalis syndrome 3.