Duffy Blood Group Genotyping in Thai Blood Donors

BACKGROUND: Duffy (FY) blood group genotyping is important in transfusion medicine because Duffy alloantibodies are associated with delayed hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. In this study, FY allele frequencies in Thai blood donors were determined by in-house PCR with sequence-specific primers (PCR-SSP), and the probability of obtaining compatible blood for alloimmunized patients was assessed. METHODS: Five hundred blood samples from Thai blood donors of the National Blood Centre, Thai Red Cross Society, were included. Only 200 samples were tested with anti-Fy(a) and anti-Fy(b) using the gel technique. All 500 samples and four samples from a Guinea family with the Fy(a-b-) phenotype were genotyped by using PCR-SSP. Additionally, the probability of obtaining antigen-negative red blood cells (RBCs) for alloimmunized patients was calculated according to the estimated FY allele frequencies. RESULTS: The FY phenotyping and genotyping results were in 100% concordance. The allele frequencies of FY*A and FY*B in 500 central Thais were 0.962 (962/1,000) and 0.038 (38/1,000), respectively. Although the Fy(a-b-) phenotype was not observed in this study, FY*B(ES)/FY*B(ES) was identified by PCR-SSP in the Guinea family and was confirmed by DNA sequencing. CONCLUSIONS: Our results confirm the high frequency of the FY*A allele in the Thai population, similar to that of Asian populations. At least 500 Thai blood donors are needed to obtain two units of antigen-negative RBCs for the Fy(a-b+) phenotype.

Duffy blood group genotypes among African-Brazilian communities of the Amazon region

Duffy blood group genotype was studied in 95 unrelated subjects from four African-Brazilian communities of the Amazon region: Trombetas, Pitimandeua, Curiaú, and Mazagão Velho. Genotyping was performed using an allele-specific primer polymerase chain reaction technique for determining the three major alleles at FY blood group, and as expected, FY*O allele was the most common one, with frequencies ranging from 56.4% in Mazagão Velho to 72.2% in Pitimandeua, whereas the FY*O/FY*O genotype was found with frequencies between 32.3% in Mazagão Velho and 58.8% in Curiaú. Genotype and allele distributions in the four Amazonian communities are consistent with a predominantly African origin with some degree of local differentiation and admixture with people of Caucasian ancestry and/or Amerindians. These results reveal that the impact of the FY*O/FY*O genotype on the transmission and endemicity of the vivax malaria deserves to be investigated in full detail in an attempt to identify the contribution of host biological factors and explain the non-homogeneous prevalence of malaria in the region expressed by its different levels of exposure

The mutation G298A®Ala100Thr on th coding sequence of the Duffy antigen/chemokine receptor gene in non-caucasian Brazilians

Ala100Thr has been suggested to be a Caucasian genetic marker on the FY*B allele. As the Brazilian population has arisen from miscegenation among Portuguese, Africans, and Indians, this mutation could possibly be found in Euro- and Afro-Brazilians, or in Brazilian Indians. Fifty-three related individuals and a random sample of 100 subjects from the Brazilian population were investigated using the polymerase chain reaction and four restriction fragment length polymorphisms. Confirming the working hypothesis, among the related individuals three Afro-Brazilians (two of them a mother and daughter) and a woman of Amerindian descent had the Ala100Thr mutation on the FY*B allele. Five non-related Euro-Brazilians also carried the mutation. All nine individuals presented the Fy(a-b+) phenotype. We conclude that the Ala100Thr mutation can occur in populations other than Caucasians and that this mutation does not affect Duffy expression on red blood cells. Gene frequencies for this allele in the non-related individuals were in agreement with those of other populations. The Duffy frequencies of two Amerindian tribes were also investigated.

Asociación entre heterocigocidad materna para cinco grupos sanguíneos y éxito reproductivo / Association between maternal heterozygosity for five blood groups and reproductive success

Background: In man, blood groups are polymorphic genetic systems. Maternal fetal incompatibility phenomena should lead to an elimination rather than a maintenance of these polymorphisms. Apossible mechanism that could explain the persistence of these polymosphisms in natural populations is a selective reproductive advantage of heterozygous individuals. Aim: To explore the relationship between maternal heterozygosity for five blood grups and some obstetrical variables related to gestational success. Material and methods: Using a case control design, to every mother giving birth to a malformed child a consecutive mother, whose offspring was normal, was assigned as control. All women were typified for ABO, Rh, kidd, MNSs and Duffy blood groups. Results: Two hundred two women were studiend. There was only one stillbirth, born from a heterozygous mother for all analyzed loci. Mothers that were heterozygous or homozygous for all loci had a higher frequency of malformed children. Women homozygous for all loci had a higher frequency of living offspring than the rest of the sample. Conclusions: Heterozygous mothers for these genetic systems have a reproductive disadvantage

Grupo sanguíneo duffy en recién nacidos malformados y sus madres / Duffy blood group in malformed newborns and their mothers

The aim of this work is to analyze the distribution of Duffy blood group and the reproductive history of 148 malformed newborns and their mothers compared to 131 control pairs. The mother -child segregation of the system is analyzed using ITO matrixes. A higher frequency of heterozygote mothers for the system was found among tha malformed group compared to controls. No differences in the reproductive history was found between Duffy system homozygote or heterozygote mothers

Further study of Rh, Kell, Duffy, P, MN, Lewis and Gerbiech blood groups of the Thais.

Blood and saliva from unselected blood donors at the Blood Bank, Siriraj Hospital were studied. Two Kell positive, two Rh negative and one Gerbiech negative were found, which could be considered as rare blood type in Thailand. The commonest Rh gene complex was CDe (R11 and the presence of CDE (Rz) in this study are the usual pattern of people in Southeast Asia. Fya is very common as in other people of Asia. In the Lewis system, the incidence of Le (a + b -) was 28.48% which agree well with our previous report 30.9%. There were 410 out of 1,668, (23.17%) who were found to be Lea non-secretor and 95 of them have Lewis antibodies in their sera. Aberrant secretion patterns were also found in this study, 5 people were found to secrete A or B substances according to their blood groups but no H substance was detectable. Further investigation of Lewis groups and secretion in Thailand are needed.