[News Terms] The 'Dibaba (D--)' Blood Type, Only 110 People Worldwide

Blood stored in the blood storage facility of the Seoul Central Blood Center of the Korean Red Cross in Gangseo-gu, Seoul. Photo by Hyunmin Kim kimhyun81@

[Asia Economy Reporter Kim Jong-hwa] The D-- type is an extremely rare blood type that appears in about 1 in 300,000 people. It is one of the blood types classified by the Rh (Rhesus) blood group system and is also called the 'D type' or 'Badi Badi Badi (-D-/-D-) type.'

The Rh blood group classifies blood based on five major antigens among 45 antigens in the blood: C, c, D, E, and e. Most people are categorized as either 'Rh positive (Rh+, with D antigen)' or 'Rh negative (Rh-, without D antigen)' depending on the presence or absence of the D antigen.

The blood type that has only the D antigen is the 'D--' type. It is a blood type where only the D antigen exists among the five antigens, and since both the C and E series antigens are absent, it is denoted with two negatives '-'.

There is also a very rare blood type called 'Rh null,' which lacks all five antigens. The Rh null type appears in about 1 in 1,000,000 people. As of 2010, 43 cases of Rh null have been officially confirmed worldwide, with only 9 of them known to donate blood. Japan has 6 cases, and none have been discovered domestically yet.

As of 2006, only 3 people with the D-- type have been identified in Korea, and globally, there are only about 110. In 2004, when a mother experienced excessive bleeding, and in 2017, when a patient with infectious endocarditis required surgery, blood donations from Japan were procured for D-- type transfusions.

On the 10th, the Korean Red Cross Blood Management Headquarters urgently gathered D-- type A blood donors for a liver transplant surgery. The Blood Management Headquarters contacted donors who might have the D-- type over the past 10 years and secured a total of 5 donors, but it was reported that the amount of blood collected was insufficient for the transfusion needs.