Multiplex Ligation-Dependent Probe Amplification Identification of 17 Different β-Globin Gene Deletions (Including Four Novel Mutations) in the Uk Population

Abstract

Large deletions of the beta-globin gene cluster are problematic to diagnose, and consequently the frequency and range of these mutations in the UK is unknown. Here we present a study evaluating the efficacy of the recently available technique of multiplex ligation-dependent prob amplification (MLPA) to determine the range and frequency of these deletions in the UK population. The results revealed a large deletion mutation in 75 of 316 patient samples collected over a 3-year period. Of these, 52 had a common (deltabeta)(0)-thalassemia [(deltabeta)(0)-thal] or hereditary persistence of fetal hemoglobin (HPFH) allele and 23 had rare or novel deletions resulting in (epsilon(G)gamma(A)gammadeltabeta)(0)-thal, (G)gamma(A)gamma(deltabeta)(0)-thal and beta(0)-thal. A total of 17 different deletions were found, 10 of which were rare and four were most likely novel [Asian Indian (epsilon(G)gamma(A)gammadeltabeta)(0)-thal, African (deltabeta)(0)-thal, African beta(0)-thal and Afghanistani beta(0)-thal]. The MLPA technique detected examples from all four categories of beta-globin gene deletions and demonstrated the wide molecular basis of deletional beta-thal/HPFH in UK patients.

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

“…The deletional mutations were chosen by taking into account ethnic background and according to the published frequencies [10]. Gap-PCR protocols and the primers for the deletional mutations HPFH-1, HPFH-2, HPFH-3, Sicilian (δβ)0-thal, Chinese Gγ(Aγδβ)0-thal, Hb Lepore, Asian-Indian inversion-deletion Gγ(Aγδβ)0-thal, and Turkish inversion-deletion (δβ)0-thal were used as previously described elsewhere [13].…”

“…Despite general carrier frequency for β-globin gene mutations being reported at 2% for Turkey and at as high as 10% for Antalya Province, large deletional mutations in the β-globin gene cluster have rarely been reported so far and there is no systemic study on mutation profiles of large deletional mutations in the β-globin gene cluster in Turkey [4,5,6,7,8,9]. On the other hand, the number of studies on variety and allelic frequencies of large deletions in the β-globin gene cluster has been growing recently [2,3,10,11,12]. Previous studies revealed that HPFH-1, HPFH-2, HPFH-3, Sicilian (δβ)0-thal, Chinese Gγ(Aγδβ)0-thal, Hb Lepore, Asian-Indian inversion-deletion Gγ(Aγδβ)0-thal, and Turkish inversion-deletion (δβ)0-thal mutations are among the most recurrent large deletional mutations in the β-globin gene cluster [10,13].…”

“…On the other hand, the number of studies on variety and allelic frequencies of large deletions in the β-globin gene cluster has been growing recently [2,3,10,11,12]. Previous studies revealed that HPFH-1, HPFH-2, HPFH-3, Sicilian (δβ)0-thal, Chinese Gγ(Aγδβ)0-thal, Hb Lepore, Asian-Indian inversion-deletion Gγ(Aγδβ)0-thal, and Turkish inversion-deletion (δβ)0-thal mutations are among the most recurrent large deletional mutations in the β-globin gene cluster [10,13]. …”

“…Therefore, molecular detection of large deletions needs different approaches in the laboratory. Researchers have recently applied strategies like Southern blotting, FISH, quantitative polymerase chain reaction (PCR), multiplex ligation-dependent probe amplification (MLPA), and gap-PCR for molecular detection of large deletional mutations of the β-globin gene cluster [10,12,14,15,16]. Among them, gap-PCR is a fast and reliable method allowing us to detect the previously characterized mutations [3,13].…”

Fine-tiling array CGH to improve diagnostics for α- and β-thalassemia rearrangements

“…We have introduced the MLPA assay in our standard diagnostic routine for those cases that remain negative for mutation detection after gap‐PCR and sequencing analysis. Due to the implementation of MLPA for the detection of deletions and duplications in the α‐ and β‐globin gene clusters, a range of new rearrangements have been identified [Babashah et al, 2009; Gallienne et al, 2009; Harteveld et al, 2005; Lee et al, 2010; Liu et al, 2008; Phylipsen et al, 2010a; So et al, 2009]. However, the exact breakpoints of these deletions remain unknown.…”