Blood types of minorities in Bangkok: A study in Thai Sikhs and the Burmese blood donors

Abstract

Background : Blood types are unique to each ethnic groups. In Thailand, Sikhs are one of established ethnic minorities. They are known to have certain rare blood types which have not been systematically studied. Therefore, we studied nine blood group systems of the Sikh and Burmese blood donors in Bangkok, Thailand.

Objectives : To assess the proportion of alleles of nine blood group antigens among Thai Sikhs and Burmese blood donors.

Materials and Methods : A total of 122 samples of Thai Sikhs blood donors at Sri Guru Singh Association Mobile Unit and 189 samples of the Burmese and Mons blood donors at Jia Hong Garment Factory Mobile Unit were tested for nine blood groups of antigen system including Rh (C, E, c, e), MNS (M, N, S, s), P (P1 and P2), Lewis (Le^a and Le^b), Kidd (Jk^a and Jk^b), Duffy (Fy^a and Fy^b), Kell (K and k) and Diego (Di^a and Di^b). For ABO and Rh(D) blood group system, data of 1,597 Thai Sikhs and 189 the Burmese blood donors were taken from the National Blood Centre, Thai Red Cross Society’s database.

Results : Thai Sikhs blood donors have a higher proportion of Rh(D) negative (3.7%) than the Burmese ones (1.0%). Almost all Thai Sikhs blood donors are Rh(C) positive and Rh(e) positive. Similarly, most the Burmese blood donors are commonly Rh(C) positive (93.6%) and Rh(e) positive (97.4%). As for the MNS system, most the Burmese (96.3%) and all Thai Sikhs blood donors are Mi^a (-) and also both groups were predominantly M (+) and s (+). As for the P blood group system, the predominant allele is P1 (63.1%) in Thai Sikhs, and P2 (74.1%) in the Burmese blood donors. As for the Duffy system, Fy (a+b+) is the most common allele among the Thai Sikhs blood donors (43.4%), while Fy (a+b-) is the most common allele among the Burmese blood donors (77.2%). Allele Fy (a-b+) is common in the Thai Sikhs blood donors (21.3%) but rare in the Burmese (2.6%). The Kell antigen K (+) and Diego antigen Di^a (+), both are very rare in the Thai Sikhs and the Burmese blood donors.

Conclusion : The red cell antigen profiles of the Thai Sikhs blood donors are different from the Burmese, Mons and Thais blood donors. In additional, Thai Sikhs blood donors have distinctively higher proportion of Rh negative, Fy^a(-), S(+), and K(+) but they are absence of Mi^a (+) and Di^a (+).