Diagnosis of thalassemia carriers commonly found in Northern Thailand via a combination of MCV or MCH and PCR-based methods

Abstract

Background: Conventional diagnostic strategy for thalassemia carriers is time-consuming and requires many types of laboratory tests.

Objective : To demonstrate the possibility of a combination of MCV or MCH and a PCR-based technique in identifying α- and β-thalassemia carriers in the population of the Northern Thailand in which molecular defects causing thalassemia are well documented.

Materials and methods: Seventy northern Thai healthy adults with Hb12 g/dL, MCV 80 fL and MCH 27 pg were tested for the α- and β-globin gene mutations commonly found in Northern Thailand by a modified multiplex allele-specific PCR. The nucleotide sequencing was employed to confirm the results obtained from the PCR-based method.

Results: A combination of MCV 80 fL or MCH 27 pg and a modified multiplex allele-specific PCR was able to definitely diagnose α- and β-thalassemia carriers in 81.4% of the samples tested. These included single carriers of SEA-α thalassemia 1, of α-thalassemia 2 (3.7-kb deletion), of Hb Constant Spring, of HbE, of β^41/42(-TTCT)-thalassemia and of β^17(A-T)-thalassemia. These also included double carriers of α-thalassemia 2 (3.7-kb deletion) and β^17(A-T)-thalassemia, double carrier of Hb Constant Spring and HbE, double carrier of SEA-α thalassemia 1 and β^17A-T)-thalassemia and double carrier of α-thalassemia 2 (3.7-kb deletion) and HbE. The results obtained from the modified multiplex allele-specific PCR completely agreed with those generated from the standard nucleotide sequencing.

Conclusion: Combination of MCV or MCH and a modified multiplex allele-specific PCR might be an alternative means in detecting common α- and β-thalassemia carriers in northern Thailand. This strategy may be applied in other regions where thalassemia is endemic and globin gene mutations are well documented. Bull Chiang Mai Assoc Med Sci 2013; 46(1): 22-32