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Bellad A, Rangiah K, Sathe G, Dey G, Appadorai PK, Lokanatha H, Murthy PR, Gowdra A, Pandey A. Identification of a rare [ G γ( A γδβ) 0 ] -thalassemia using tandem mass spectrometry. Proteomics 2024:e2300495. [PMID: 38212249 DOI: 10.1002/pmic.202300495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/23/2023] [Accepted: 01/03/2024] [Indexed: 01/13/2024]
Abstract
Thalassemias are a group of inherited monogenic disorders characterized by defects in the synthesis of one or more of the globin chain subunits of the hemoglobin tetramer. Delta-beta (δβ-) thalassemia has large deletions in the β globin gene cluster involving δ- and β-globin genes, leading to absent or reduced synthesis of both δ- and β-globin chains. Here, we used direct globin-chain analysis using tandem mass spectrometry for the diagnosis of δβ-thalassemia. Two cases from unrelated families were recruited for the study based on clinical and hematological evaluation. Peptides obtained after trypsin digestion of proteins extracted from red blood cell pellets from two affected individuals and their parents were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Mass spectrometric analysis revealed a severe reduction in δ, β, and Aγ globin proteins with increased G γ globin protein in the affected individuals. The diagnosis of G γ(A γδβ)0 -thalassemia in the homozygous state in the affected individuals and in the heterozygous state in the parents was made from our results. The diagnosis was confirmed at the genetic level using multiplex ligation-dependent probe amplification (MLPA). Our findings demonstrate the utility of direct globin protein quantitation using LC-MS/MS to quantify individual globin proteins reflecting changes in globin production. This approach can be utilized for accurate and timely diagnosis of hemoglobinopathies, including rare variants, where existing diagnostic methods provide inconclusive results.
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Affiliation(s)
- Anikha Bellad
- Manipal Academy of Higher Education, Manipal, Karnataka, India
- Institute of Bioinformatics, International Technology Park, Bangalore, Karnataka, India
| | - Kannan Rangiah
- Manipal Academy of Higher Education, Manipal, Karnataka, India
- Institute of Bioinformatics, International Technology Park, Bangalore, Karnataka, India
| | - Gajanan Sathe
- Institute of Bioinformatics, International Technology Park, Bangalore, Karnataka, India
| | - Gourav Dey
- Institute of Bioinformatics, International Technology Park, Bangalore, Karnataka, India
| | | | - Hemalatha Lokanatha
- Department of Pathology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Pradeep Rudra Murthy
- Department of Pathology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Aruna Gowdra
- Department of Biochemistry, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Akhilesh Pandey
- Manipal Academy of Higher Education, Manipal, Karnataka, India
- Institute of Bioinformatics, International Technology Park, Bangalore, Karnataka, India
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
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Bilgen T, Altıok Clark Ö, Öztürk Z, Yeşilipek MA, Keser İ. Gap-PCR Screening for Common Large Deletional Mutations of β-Globin Gene Cluster Revealed a Higher Prevalence of the Turkish Inversion/Deletion (δβ)0 Mutation in Antalya. Turk J Haematol 2015; 33:107-11. [PMID: 26377447 PMCID: PMC5100720 DOI: 10.4274/tjh.2014.0242] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE Although the calculated carrier frequency for point mutations of the β-globin gene is around 10% for Antalya Province, nothing is known about the profile of large deletional mutations involving the β-globin gene. In this study, we aimed to screen common deletional mutations in the β-globin gene cluster in patients for whom direct DNA sequencing was not able to demonstrate the mutation(s) responsible for the disease phenotype. MATERIALS AND METHODS Thirty-one index cases selected with a series of selection events among 60 cases without detected β-globin gene mutation from 580 thalassemia-related cases tested by direct sequencing over the last 4 years in our diagnostic center were screened for the most common 8 different large deletional mutations of the β-globin gene cluster by gap-PCR. RESULTS We detected 1 homozygous and 9 heterozygous novel unrelated cases for the Turkish inversion/deletion (δβ)0 mutation in our series of 31 cases. Our study showed that the Turkish inversion/deletion (δβ)0 mutation per se accounts for 16.6% of the unidentified causative alleles and also accounts for 1.5% of all detected mutations over the last 4 years in our laboratory. CONCLUSION Since molecular diagnosis of deletional mutations in the β-globin gene cluster warrants different approaches, it deserves special attention in order to provide prenatal diagnosis and prevention opportunities to the families involved. We conclude that the Turkish inversion/deletion (δβ)0, as the most prevalent deletional mutation detected so far, has to be routinely tested for in Antalya, and the gap-PCR approach has valuable diagnostic potential in the patients at risk.
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Affiliation(s)
- Türker Bilgen
- Namık Kemal University Central Research Laboratory (NABİLTEM), Tekirdağ, Turkey, E-mail : ,
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