SETTING: Haematology Lab, Department of Biomedical Science, University of Malaya.
PARTICIPANTS: Eight couples characterised as β-thalassaemia carriers where both partners posed the same β-globin gene mutations at CD41/42, IVS1-5 and IVS2-654, were recruited in this study.
OUTCOME MEASURES: Genotyping was performed by allele specific-PCR and the locations of SNPs were identified after sequencing alignment.
RESULTS: Genotype analysis revealed that at least one paternal SNP was present for each of the couples. Amplification on free-circulating DNA revealed that the paternal mutant allele of SNP was present in three fcDNA. Thus, the fetuses may be β-thalassaemia carriers or β-thalassaemia major. Paternal wild-type alleles of SNP were present in the remaining five fcDNA samples, thus indicating that the fetal genotypes would not be homozygous mutants.
CONCLUSIONS: This preliminary research demonstrates that paternal allele of SNP can be used as a non-invasive prenatal diagnosis approach for at-risk couples to determine the β-thalassaemia status of the fetus.
CASE REPORT: In this case series, we report on two cases of WT which had poor response to pre-operative chemotherapy. Both cases underwent surgery after pre-operative chemotherapy and recovery was uneventful during a two-year follow-up.
DISCUSSION: Both patients had chemotherapy prior planned surgery, but had unfortunate poor tumour response. The tumour progressed in size which required a radical nephrectomy. The histology report for the first case had more than 60% blastemal cells remaining despite giving pre-operative chemotherapy with no focal anaplasia. This showed poor response to chemotherapy evidenced by the high number of blastemal cells. The second case was a stromal type WT which is known for poor response and may lead to enhancement of growth and maturation induced by chemotherapy. These were the possible reason of poor response of WT in these two cases.
METHODS: The purpose of this study was to design an assay for the detection of triplications, common and rare deletional alpha thalassaemia using droplet digital PCR (ddPCR).
RESULTS: This is a quantitative detection method to measure the changes of copy number which can detect deletions, duplications and triplications of the alpha globin gene simultaneously.
CONCLUSION: In conclusion, ddPCR is an alternative method for rapid detection of alpha thalassaemia variants in Malaysia.