{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T11:31:37Z","timestamp":1792150297841,"version":"4.4.0"},"reference-count":47,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2025,9,9]],"date-time":"2025-09-09T00:00:00Z","timestamp":1757376000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Alpha-thalassemia is most often caused by large deletions within the \u03b1-globin gene cluster which reduce or abolish \u03b1-globin chain synthesis. Several common deletions are well described, but atypical structural variants remain underdiagnosed. In this study, we report three novel large heterozygous deletions of the \u03b1-globin cluster. The variants were identified in unrelated patients who presented with persistent microcytosis and hypochromia in the absence of iron deficiency or structural hemoglobin variants. A stepwise molecular diagnostic approach was applied. It combined commercial deletion screening assays, Sanger sequencing, Multiplex Ligation-dependent Probe Amplification (MLPA), and targeted Next-Generation Sequencing (NGS) with the Devyser Thalassemia panel. MLPA detected three deletions ranging from ~17 kb to ~360 kb. All involved the critical HS-40 regulatory region and both HBA1 and HBA2 structural genes, consistent with \u03b10-thalassemia alleles. Next-Generation Sequencing confirmed the extent of each deletion and refined their genomic boundaries. Comparative genomic mapping showed that these deletions are distinct from classical variants such as --SEA or --MED, indicating novel structural configurations. Clinically, all patients displayed a carrier phenotype, with normal HbF levels (&lt;1%) and normal or slightly reduced HbA2 values. This study broadens the mutational spectrum of \u03b10-thalassemia and demonstrates the diagnostic value of combining MLPA and NGS in patients with unexplained microcytosis. By enabling accurate distinction from iron-deficiency anemia and other microcytic disorders, these findings have direct translational implications for improving diagnostic precision and genetic counseling in clinical practice.<\/jats:p>","DOI":"10.3390\/ijms26188783","type":"journal-article","created":{"date-parts":[[2025,9,10]],"date-time":"2025-09-10T10:27:12Z","timestamp":1757500032000},"page":"8783","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Molecular Characterization of Three Novel Large Deletions Causing \u03b10-Thalassemia"],"prefix":"10.3390","volume":"26","author":[{"given":"Sara","family":"Ferrer-Benito","sequence":"first","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"},{"name":"Grupo de Investigaci\u00f3n en Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, Instituto de Investigaci\u00f3n Sanitaria Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mar\u00eda Pilar","family":"Ricard Andr\u00e9s","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Universitario Fundaci\u00f3n Alcorc\u00f3n, 28922 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7770-7114","authenticated-orcid":false,"given":"Mar\u00eda Jos\u00e9","family":"Mur\u00fazabal","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Universitario Marqu\u00e9s de Valdecilla, 39008 Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jorge M.","family":"Nieto","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"},{"name":"Grupo de Investigaci\u00f3n en Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, Instituto de Investigaci\u00f3n Sanitaria Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fernando A.","family":"Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"},{"name":"Grupo de Investigaci\u00f3n en Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, Instituto de Investigaci\u00f3n Sanitaria Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bel\u00e9n","family":"Ortega-Montero","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Villegas","sequence":"additional","affiliation":[{"name":"Facultad de Medicina, Complutense University of Madrid, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Celina","family":"Benavente","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"},{"name":"Grupo de Investigaci\u00f3n en Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, Instituto de Investigaci\u00f3n Sanitaria Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5126-5039","authenticated-orcid":false,"given":"Paloma","family":"Ropero","sequence":"additional","affiliation":[{"name":"Servicio de Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"},{"name":"Grupo de Investigaci\u00f3n en Hematolog\u00eda, Hospital Cl\u00ednico San Carlos, Instituto de Investigaci\u00f3n Sanitaria Hospital Cl\u00ednico San Carlos, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1186\/1750-1172-5-13","article-title":"Alpha-thalassaemia","volume":"5","author":"Harteveld","year":"2010","journal-title":"Orphanet J. 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