A study of children with acute leukaemia found a statistically significant difference in the blood groups of the patients depending on the type of leukaemia diagnosed. The multicenter study, published in the journal Pediatric hematology and oncology,(1) analysed blood group data in patients under 12 years with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML)

In the ALL group there were more patients with blood group O and fewer patients with blood group A and B [confirming the results of an earlier study(2)]. In the AML group there were more patients with blood group A. The authors of the study conclude that "alteration in ABO antigens might be associated with an increased risk of ALL."(1)

This complements the information available in the Complete Blood Type Encyclopedia, which cites a study showing significantly lower incidence of acute (rapidly growing) leukaemia in females of blood group O, suggesting a sex-responsive gene near the ABO locus protecting females against acute leukaemia.(3)(4) In relation to diet there are also significant associations with acute leukaemia in women and consumption of milk, tea, beer, wine and beef.(5)

Individuals with the A2 phenotype have also been found to be significantly higher in a study of patients with chronic lymphocytic leukaemia.(6) Of other polymorphisms associated with leukaemia, slow metabolisers of the cytochrome P450 (CYP) polymorphisms 2C19 and 2D6 were found to be significantly higher in patients with acute leukaemia,(7) and folic acid metabolism.(8) Cytochrome P450 plays a central role in drug and xenobiotic metabolism as well as synthesis of stress hormones, metabolism of fat-soluble vitamins and polyunsaturated fatty acids. The CYP 2C19 slow metaboliser polymorphism was also found to affect personality traits in a study of Japanese females.(9) Of the 487 Japanese volunteers in the study, those found to have slow or fast metabolism of this cytochrome were compared. Female slow metabolisers had significantly lower scores for reward dependence, cooperativeness and self-transcendence than in fast metabolisers. In males, none of the seven personality traits was significantly different between slow and fast metabolisers. CYP 2C19 metabolizes sex hormones and 5-hydroxytryptamine, which are involved in multiple brain functions.

Follow up:

References
1. Alavi S, Ashraf H, Rashidi A. "Distribution of abo blood groups in childhood acute leukemia." Pediatr Hematol Oncol. 2006 Dec;23(8):611-7. PubMed 17065136

2. Vadivelu M, Damodaran S, Solomon J, Rajaseharan A. "Distribution of ABO blood groups in acute leukaemias and lymphomas". Ann Hematol 2004 Sep;83(9):584-7. PubMed 15175895

3. D'Adamo, Peter J. The Eat Right for Your Type Complete Blood Type Encyclopedia. Pub. Riverhead Books, New York, 2002. ISBN 1-57322-920-2. p.194

4. Jackson N, Menon BS, Zarina W, Zawawi N, Naing NN. "Why is acute leukemia more common in males? A possible sex-determined risk linked to the ABO blood group genes." Ann Hematol. 1999 May;78(5):233-6. PubMed 10391104

5. Li Y, Moysich KB, Baer MR, et. al. "Intakes of selected food groups and beverages and adult acute myeloid leukemia." Leuk Res. 2006 Dec;30(12):1507-15. Epub 2006 May 5. PubMed 16678899

6. Janardhana V, Propert DN, Green RE. "ABO blood groups in hematologic malignancies." Cancer Genet Cytogenet. 1991 Jan;51(1):113-20.
PubMed 1984838

7. Roddam PL, Rollinson S, Kane E. et. al. "Poor metabolizers at the cytochrome P450 2D6 and 2C19 loci are at increased risk of developing adult acute leukaemia." Pharmacogenetics. 2000 Oct;10(7):605-15. PubMed 11037802

8. Morgan GJ, Smith MT. "Metabolic enzyme polymorphisms and susceptibility to acute leukemia in adults."
Am J Pharmacogenomics. 2002;2(2):79-92. PubMed 12083944

9. Ishii G, Suzuki A, Oshino S, Shiraishi H, Otani K. "CYP2C19 polymorphism affects personality traits of Japanese females." Neurosci Lett. 2006 Oct 17. PubMed 8521680