ABO blood groups and psychiatric disorders: a Croatian study

Background. The prevalence of ABO alleles is different in different populations, and many studies have shown a correlation between the occurrences of some diseases and different genotypes of ABO blood groups. The aim of this study was to determine whether there is a significant association between psychiatric syndromes and ABO blood groups. Materials and methods. This case-control study involved 156 psychiatric patients and 303 healthy, unrelated, voluntary blood donors. Genomic DNA was isolated from blood on a QIAcube device using a QIAamp DNA Blood mini QIAcube kit. ABO genot, ping on five basic ABO alleles was performed using allele-specific polymerase chain reaction analysis. Results. Compared with healthy subjects, a significantly higher proportion of psychiatric patients had AB blood group (chi(2)=9,359, df=3, p=0.025) and, accordingly a significantly higher incidence of A I B genotype (chi(2)=8.226, df=3, p=0.042). The odds ratio showed that psychiatric disorders occur almost three times more frequently in carriers of AB group compared to other blood groups. However, no statistically significant difference was found w the distribution of ABO blood groups among patients with different psychiatric diagnoses. Likewise, no correlations were found between ABO blood groups and other characteristics of the psychiatric patients (sex, psychiatric heredity, somatic comorbidity, suicidality). Conclusions. The results of this study support the hypothesis of an association between psychiatric disorders and ABO blood groups. T he probability is that psychiatric disorders will occur almost three times more frequently in carriers of AB group compared to other ABO blood groups in the Croatian population.