ABO blood group system alleles in white individuals of the ABO gene that produce one's blood type: The same study also identified 18 rare alleles, which generally have a weaker glycosylation activity. People with weak alleles of A can sometimes express anti-A antibodies, though these are usually not clinically significant as they do not stably interact with the antigen at body temperature. Cis AB is another rare variant, in which A and B genes are transmitted together from a single parent. The distribution of the blood groups A, B, O and AB varies across the world according to the population. There are also variations
Jehovah's Witnesses and blood transfusions by failing to report any benefits of blood-based treatment. Nor do its publications acknowledge that in some situations, including rapid and massive haemorrhage, there are no alternatives to blood transfusions. He claims Watch Tower Society publications often discuss the risk of death as a result of refusing blood transfusions, but give little consideration to the prolonged suffering and disability, producing an added burden on family and society, that can result from refusal. Attorney and former Witness Kerry Louderback-Wood also claims that Witness publications exaggerate the medical risks of taking blood and the efficiency of non-blood medical therapies in critical situations.