Asociación entre grupo sanguíneo Kidd y malformaciones congénitas / Association between Kidd blood group and congenital malformations

Background: Since the discovery of blood groups, an association between these genetic polymorphisms and pathological phenotypes has been searched, looking for factors involved in the pathogenesis of diseases or biological population mechanisms that maintain these polymorphisms. In previous reports, we have described some associations between erythrocytic genetic marker segregation and the presence of congenital malformations. Aim: To explore the association between Kidd blood group and congenital malformations. Patients and methods: One hundred twenty two malformed newborns and their mothers and 136 normal newborns, seen at the Clinical Hospital of the University of Chile, were studied. Results: Kidd blood group segregation distortions were found among male malformed newborns, that were not present in normal newborns. Among mothers of both groups of newborns, a paucity of heterozygous for this system was found. Conclusions: The association found between a blood group and congenital malformations, allows to state that malformed children have a different genetic background, when compared to normal children

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

Estudio de paternidad aplicando el polimorfismo de DNA: evaluación en relación a los métodos convencionalmente usados en Chile / Paternity study applying DNA polimorphism: evaluation in relation to conventional methods used in Chile

Simultaneous detection of several VNTR loci using a single DNA probe is the basis of the technique called DNA fingerprint (DNAfp) of increasing application in parenthood identification. According to the data gathered by different laboratories worldwide, father exclusion can be made in a larger number of cases when compared with the customary tests based on erythrocyte antigens. The question could then be whether DNAfp will completely replace erythrocyte antigen tests. We report here our experience in applying DNAfp to 92 samples corresponding to 34 paternity cases and comparing these with the results obtained with the antigens of the systems ABO, Rh. MNSs, Duffy and Kidd. Most of the HaeIII/digested DNA samples produced 13 to 16 bands larger than 4,3 Kb (average 14,0761ñ2,205). Average band sharing between pairs of unrelated individual was 1,907ñ1,083. Two cases presenting an a posteriori probability of being the father of 80.7 percent and 76.5 percent by erythrocyte antigens were clearly excluded by DNAfp. All exclusions made by antigens were confirmed by DNAfp. In the cases reported as father probable (28 cases) by DNAfp, these shared with the child 6,7407ñ1,7 bands on average. Because of time, cost and simplicity we favor a procedure starting with the antigens test and continuing with DNAfp only when an exclusion is not possible. Economy will increase as the number of exclussions increases