Detection and characterisation of β-globin gene cluster deletions in Chinese using multiplex ligation-dependent probe amplification
Detection and characterisation of β-globin gene cluster deletions in Chinese using multiplex ligation-dependent probe amplification
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DOI:
10.1136/jcp.2009.067538
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发表时间:
2009-12-01
影响因子:
3.4
通讯作者:
Chan, L. C.
中科院分区:
文献类型:
--
作者:
So, C. C.;So, A. C. Y.;Chan, L. C.
Background: Deletions in the beta-globin cluster causing thalassaemia and hereditary persistence of fetal haemoglobin (HPFH) are uncommon and difficult to detect. Data in Chinese are very scarce.Aims: To use a recently available technique to investigate the frequencies and nature of beta-globin cluster deletions in Chinese.Methods: 106 subjects with phenotypes of thalassaemia or HPFH and suspected to have deletions in the b-globin cluster were studied. A commercially available kit employing multiplex ligation-dependent probe amplification (MLPA) was used to screen for deletions. Gap PCR and direct nucleotide sequencing were used to characterise deletions detected.Results: 17 deletions in the b-globin cluster were found in 17 patients: 8 of Chinese ((A)gamma delta beta)(0) thalassaemia, 7 of Southeast Asian (Vietnamese) deletion and 2 of Thai ((A)gamma delta beta)(0) thalassaemia. The only type of deletion detected in delta beta-thalassaemia was Chinese ((A)gamma delta beta)(0) thalassaemia. The deletional form of HPFH was rarely seen in only 1 case of Thai ((A)gamma delta beta)(0) thalassaemia. Deletions presenting as beta-thalassaemia trait and raised HbF were all of the Southeast Asian (Vietnamese) deletion type. When these deletions were co-inherited with classical beta-thalassaemia mutations in compound heterozygous states, the phenotypes could be very variable.Conclusions: In the Chinese population, there are only relatively few types of deletions seen in the beta-globin cluster. MLPA is a fast and effective way of screening for these deletions. Characterisation of these deletions allows the development of simpler and more specific PCR-based tests for routine diagnostic use. Accurate prediction of phenotype is not always feasible. The molecular defects in many cases of HPFH still await discovery.