Bioeksperimen
Vol. 12 No. 2: September 2026

Prediction of hemoglobin protein structure and function of the α4.2 deletion mutation and αα/-α4.2/βCD8 (-AA)/βN co-inheritance

Nurul Fitri T Tagunu (Magister Biology Study Program Faculty of Biology, Universitas Gadjah Mada)
Tri Ratnaningsih (Department of Clinical Pathology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada
Thalassemia Research Group, Universitas Gadjah Mada)

Nur Imma Fatimah Harahap (Department of Clinical Pathology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada
Thalassemia Research Group, Universitas Gadjah Mada)

Indra Lesmana (Department of Tropical Biology, Faculty of Biology, Universitas Gadjah Mada
Thalassemia Research Group, Universitas Gadjah Mada)

Niken Satuti Nur Handayani (Department of Tropical Biology, Faculty of Biology, Universitas Gadjah Mada
Thalassemia Research Group, Universitas Gadjah Mada)



Article Info

Publish Date
28 Sep 2026

Abstract

The α4.2 deletion is typically characterized as a silent mutation. The clinical impact of this mutation can vary, particularly when inherited alongside other globin gene mutations, for example co-inheritance with β-thalassemia mutations, such as βCD8 (-AA)/βᴺ. This study aims to determine the α4.2 deletion breakpoint and analyze the structural and functional impact of α-thalassemia heterozygous mutation associated with α4.2 deletion and co-inheritance of αα / -α4.2/ βCD8 (-AA) / βN on the resulting hemoglobin protein. DNA sample was sequenced using the Sanger method by 1st BASE laboratory. Sequence alignment was performed via Clustal Omega, while hemoglobin structure prediction and analysis were conducted using UCSF Chimera (Chimera-1.19) and BIOVIA Discovery Studio. The results identified the α4.2 deletion breakpoint between nucleotide 26 of the X2 box and nucleotide 347 of the X1 box. Despite the mutations, the α4.2 deletion and the αα / -α4.2/ βCD8 (-AA) / βN co-inheritance resulted in a protein structure identical to normal residues, maintaining all stabilizing interactions. Therefore, we conclude that in silico predictions indicate no major structural deviations from wild-type hemoglobin A for both the α4.2 deletion and the co-inheritance of αα/-α4.2 with βCD8 (-AA)/βN. This is consistent with the molecular nature of α-thalassemia deletions, which primarily affect globin gene dosage rather than amino acid sequence, although this observation is limited to computational analysis and has not been experimentally confirmed.

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Journal Info

Abbrev

bioeksperimen

Publisher

Subject

Biochemistry, Genetics & Molecular Biology

Description

Aim Bioeksperimen: Jurnal Penelitian Biologi is a peer-reviewed, open-access scientific journal dedicated to advancing knowledge across a broad spectrum of biological sciences through the publication of high-quality original research articles. The journal promotes rigorous experimental and ...