1
|
Moore JA, Pullon BM, Drake KM, Brennan SO. Novel α 0-Thalassemia Deletion Identified in an Indian Infant with Hb H Disease. Hemoglobin 2020; 44:297-301. [PMID: 32722952 DOI: 10.1080/03630269.2020.1797774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We report the identification of a large deletion of the α-globin gene cluster, which removed both HBA2 and HBA1 and included the region from HBZ to HBQ1 on chromosome 16 (16p13.3). The α0-thalassemia (α0-thal) deletion was discovered in an Indian family residing in New Zealand. The proband was a 3-month-old female, who presented with a Hb H disease of unknown molecular origin. Routine hematology showed marked hypochromic microcytic anemia, with numerous Hb H inclusion bodies. In the absence of iron deficiency, there was a strong clinical suspicion of α-thal. On initial screening using a multiplex gap polymerase chain reaction (gap-PCR), only the common rightward deletion (-α3.7) was detected. Investigation of the proband's mother and father revealed the mother was heterozygous for the -α3.7 deletion, while none of the seven most common pathogenic α-thal deletions were detected in the father. Multiplex ligation-dependent probe amplification (MLPA) was employed to detect the presence of a novel α0-thal deletion in both the proband and her father. For the proband, the α0-thal deletion in combination with the -α3.7 deletion, eliminated three copies of HBA consistent with a clinical diagnosis of Hb H disease.
Collapse
Affiliation(s)
- Jordyn A Moore
- Specialist Biochemistry, Canterbury Health Laboratories, Christchurch, New Zealand
| | - Beverley M Pullon
- Technical Specialist Haemolytics, Waikato Hospital, Hamilton, New Zealand
| | - Kylie M Drake
- Molecular Pathology Department, Canterbury Health Laboratories, Christchurch, New Zealand
| | - Stephen O Brennan
- Specialist Biochemistry, Canterbury Health Laboratories, Christchurch, New Zealand
| |
Collapse
|
2
|
Mota NO, Kimura EM, Ferreira RD, Pedroso GA, Albuquerque DM, Ribeiro DM, Santos MNN, Bittar CM, Costa FF, Sonati MDF. Rare α0-thalassemia deletions detected by MLPA in five unrelated Brazilian patients. Genet Mol Biol 2017; 40:768-773. [PMID: 28981562 PMCID: PMC5738609 DOI: 10.1590/1678-4685-gmb-2016-0330] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 07/23/2017] [Indexed: 11/21/2022] Open
Abstract
Alpha-thalassemias are among the most common genetic diseases in the world. They are characterized by hypochromic and microcytic anemia and great clinical variability, ranging from a practically asymptomatic phenotype to severe anemia, which can lead to intrauterine or early neonatal death. Deletions affecting the α-globin genes, located on chromosome 16p13.3, are the main causes of α-thalassemia. Multiplex ligation-dependent probe amplification (MLPA) can be used to detect rearrangements that cause α-thalassemia, particularly large deletions involving the whole α cluster and/or deletions in the HS-40 region. Here, MLPA was used to investigate the molecular basis of α-thalassemia in five unrelated patients, three of whom had Hb H disease. In addition to the -α3.7 deletion identified in the patients with Hb H disease, four different α0 deletions removing 15 to 225 kb DNA segments were found: two of them remove both the α genes, one affects only the regulatory element (HS-40) region, and another one extends over the entire α cluster and the HS-40 region. These results illustrate the diversity of α-thalassemia deletions in the Brazilian population and highlight the importance of molecular investigation in cases that present with microcytosis and hypochromia without iron deficiency and normal or reduced Hb A2 levels..
Collapse
Affiliation(s)
- Natália O Mota
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Elza M Kimura
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Roberta D Ferreira
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Gisele A Pedroso
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Daniela M Ribeiro
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Magnun N N Santos
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Fernando F Costa
- Hemocentro, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Maria de Fatima Sonati
- Laboratório de Hemoglobinopatias, Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| |
Collapse
|